The new material editor in Accurender nXt has 2 modes, simple and advanced. This tutorial covers how to create a displacement grass texture using the advanced settings in nXt. To do this tutorial, you will need two bitmaps. One for the displacement, and one for the grass texture. This tutorial will show how to create the displacement using Corel Photo-Paint (other Photo something software should be simular). The Displacement Map and Grass Texture can be downloaded from AccuStudio, for this tutorial we will use grass_noise.png and grass_garand.jpg. Note: the default displacement used in this tutorial is black and white. You can use a gray scale noise image to soften and vary the length of the grass some. The gray scale image is grass_noise_gs.png.

Launch Photo-Paint and create a new image. Set it up with a resolution of 200x200 at 100dpi with a white background. Select Effects > Noise > Add Noise. This will create a gray scale speckled image. Each pixal represents a blade of grass. The simplest way to convert it to black and white is to use the 3D Noise, select Effects > Noise > 3-D Stereo Noise. An alternate method is to convert it to 1 bit, Black and White, you will need to play with the method to get the best random pixal placement with this method. Save you image to PNG Note: to create a gray scale image, do not do the 3D noise (or convert to 1 bit) and continue to apply the noise setting 2 or 3 times more, until you achive the desired density.

The next step is to launch AutoCAD then Accurender nXt by typing AR5 at the command prompt. On the nXt pallete Click the double down arrow next to Materials to expand the materials section. To create a new Textured material, click on the little down arrow next to the sphere on the left and select Textured...

A dialog appears, select your displacement map. On the material Dialog, click the Advanced button.

Once the Advanced Dialog appears, click on the Textures tab. This is where you change the settings to the displacement map and add the grass texture.

Before adding the grass texture, verify that the settings are correct for your displacement map. The size of the map, may not come in correctly, in this case we are working in the Imperial units and will set the maps to 24x24. Change "Type" to Displacement map, set Height to 150 (100 to 150 for short grass and 300 for tall grass), Facet Size 1 to 5 and leave Z Offest at -0.50, then click OK to close this dialog.

Next add your Grass Texture map, from the Textures tab, click one of of the blank Image buttons. a selection dialog appears. After you select the Grass Texture map, the image properties will show up. For our Grass, we have changed the Tiles size to match base bitmap (48x32.51) set the Bump to 0.25 and leave all of the other settings as is. After you have adjusted size, click OK.

After each bitmap has been added, you can rename and then save the new Texture. Edit the name and then click OK.

Apply the material to an object or layer and then render. Note: a displacement texture comes with a performance hit. The grass adds almost 2 BILLION Apparent Faces to this model. It took 2 hours to do 100 passes.

The new material editor in Accurender nXt has 2 modes, simple and advanced. This tutorial covers how to create a wood flooring using the advanced settings in nXt. To do this tutorial, you will need three bitmaps. One for the base (diffuse), bump and reflectivity. http://www.arroway-textures.de/ is a good source, but please read their terms of use first before downloading.

The first step is to launch Accurender nXt by typing AR5 at the command prompt. On the nXt pallete Click the double down arrow next to Materials to expand the materials section. To create a new Textured material, click on the little down arrow next to the sphere on the left and select Textured...

 A dialog appears, select your base texture. On the material Dialog, click the Advanced button.

Once the Advanced Dialog appears, click on the Textures tab. This is where you add additional textures for bump mapping and

Before adding the bump and reflectivity maps, verify that the settings are correct for your base bitmap. The size of the map, may not come in correctly, in this case we are working in the Imperial units and will set the maps to 180x405. All of the other settings will remain as is, so click OK to close this dialog.

Next add your BUMP map, from the Textures tab, click on of the blank Image buttons. a selection dialog appears. After you select the bump map, the image properties will show up. For our wood flooring, we have changed the Tiles size to match base bitmap (180x405) set the Bump to 0.25 and on the Advanced tab uncheck Base Color. After you have adjusted all of the settings, click OK.

Next we add our reflectivity map. Once again, from the Textures tab, click on of the blank Image buttons. a selection dialog appears. After you select the reflectivity map, the image properties will show up. Changed the Tiles size to match base bitmap (180x405) set the Strengthto 0.05 and on the Advanced tab uncheck Base Color and then check Highlight Intensity. After you have adjusted all of the settings, click OK.

After each bitmap has been added, you can rename and then save the new Texture. Edit the name and then click OK. 

Apply the material to an object or layer and then render.

This tutorial covers proper modeling and lighting in an interior rendering.

Introduction

You have created an interior model. You click render, the lighting is flat, shadows are lifeless and there are artifacts all over place. the best way to over come this is to setup up your model correctly from the beginning. Also, a very important note about rendering, over 2/3 of the time is in setting your lights up, not in the modeling of the object. So it is best to be patient in getting just the right lighting. Before you jump into this tutorial, it is assumed that you have a basic understanding of Accurender and know where the settings are.

In the following text, AR3 refers to AccuRender v. 3.1.

If you want to use the same AutoCAD models illustrated in this tutorial. The materials for the models can be found in Accustudio MLIB 23. The links are provided below.

• Tutorial 01 Model (AutoCAD 2000 format)
• Tutorial 02 Model (AutoCAD 2000 format)
• Accustudio Materials (models require MLIB 23)

Creating Your Model

There are a few important rules to observe when constructing a model for Radiosity calculation and interior rendering which can be seen in the interior tutorial 01 drawing.

• Make sure all flat surfaces are continuous. A wall with windows in it is best constructed as a single region so there are no join lines. Plain walls can be 3D faces, thick lines or regions, whichever takes your fancy.

• Make sure all walls, ceilings and floors meet up exactly rather than overlapping. This will minimize the number of Artifacts occurring at join lines. Cut ceilings and floors round pillars. Don’t worry about details such as skirting, door frames, window frames, coving etc. These will be dealt with later.

• Don’t model detail that won’t be seen from the interior viewpoint as it will only slow the rendering down and not contribute anything to the final image.
• Ideally model window panes as thin 3D faces

Preparing your model for Accurender

Apart from assigning materials to your objects and layers, there are certain object properties that need to be set to ensure that everything renders correctly which can be seen in the interior tutorial 02 drawing. It’s worth mentioning a few words at this point about “Molding and Trim” and “Raytrace Only”:

If you tag an object as Molding and Trim, it won’t cast Radiosity shadows or reflect Radiosity light. It will, however receive Radiosity light. To regain the shadows during Raytracing you must check the Recalculate Lights box.

If you tag an object as Raytrace Only, then it is completely omitted from the Radiosity calculation, neither reflecting nor receiving Radiosity light. This obviously makes the Radiosity calculation faster and avoids unsightly artifacts, however, unless the object is directly lit, it will appear darker as it is not benefiting from reflected light round the room. As a rule of thumb, only use this setting on shiny metal and glass objects.

The decision to include or exclude an object from the Radiosity calculation can be made by answering the simple question; “Will this object make a significant contribution to the distribution of light within the model?”. Be careful though, one chair in a large room may not, but 100 chairs may.

• Tag everything that is not curved as No Smooth Shading. This ensures that Accurender doesn’t try to “round off” flat surfaces. 

• Tag skirting, door frames and window frames as Molding and Trim. These are small details which have been placed on top of a large flat surface and have no real contribution to the overall light distribution in the room. Most small objects used to dress an interior should also be tagged.

• Tag all chrome and glass objects as Molding and Trim and Raytrace Only. You may be able to get away with just Raytrace Only but there’s no harm in tagging both just to be on the safe side.

• Additionally tag windows, window frames and particularly blinds and mullions as Window Covering so that they don’t cast weird shadows from the ambient light coming from outside. Tag window panes as Thin under Type. You can also tag blinds as No Raytrace Shadows if you don’t have direct sunlight coming through the window.

• Make sure objects with a directional material applied, such as floor boards are mapped correctly through the Object Properties dialogue box.

• Ensure that all objects inserted into your interior such as tables and chairs are Radiosity friendly. For example, a table top should be included in the Radiosity calculation, but the legs should be tagged as Molding and Trim. A glass vase can be tagged as Raytrace Only.

Lighting Your Model

There are hundreds of different options when it comes to lighting, most of which are covered in the Accurender manual. The most accurate simulation comes from Goniometric lights with IES data attached to them which can give you the exact light distribution from a specific light fitting.

However, the main light source in most interiors is the light coming in through the windows and one of the biggest problems can be balancing this with the interior lights.

In the sample drawing interior tutorial 02 there are just two types of light source: Accurender Rectangular lights (600x1200mm) and Daylight.

Basic Accurender lights are very useful for experimenting with as you can change their settings very easily as opposed to Light Fittings which have set values.

Position your overhead lights a few millimeters lower than the ceiling and tag them as Molding and Trim so as to avoid artifacts. The layer on which you insert your lights should be Black/White in colour otherwise your light source will take on a hue based on the layer colour. Make sure when using grid lights that the mapping origin point of the ceiling lines up with the corner of one of the lights. Set the type and brightness of the light to real world values e.g. 300W Fluorescent.

Daylight Openings simulate the ambient light coming in from outside. They have no settings themselves (apart from being able to obstruct outside light by percentage), they just indicate where the light is coming in from outside. All the settings to do with exterior light are found under the Sun properties.

Daylight Openings should be positioned outside the window with the center line pointing in. Anything behind the line of the daylight opening will not receive ambient light. Size the Daylight Opening such that it is slightly smaller than the window. If there are blinds in front of the window then alter the Obstructed value accordingly. For large windows it is best to use several smaller Daylight Openings for a more accurate calculation.

The following settings will make a good starting point for a daytime shot (the results of years of trial and error):

You may want to alter the Cloudiness setting depending on your background image (see below). For more of a twilight shot simply reduce the Sun and Sky values to 0.05 or thereabouts.

Make sure for the final Raytrace you set Antialiasing to as high as you dare, noise to 0.05 and check Soft Shadows and Recalculate Lights.

Setting the Environment

Many interior renderings are let down badly by the view outside the window, often an inappropriate scene thrown in at the last minute without any consideration for perspective or lighting.

Firstly choose an image that is suitable for the location of the interior with the light coming from approximately the right direction (you can always reverse the image). It may also be desirable to blur the image slightly so it doesn’t dominate the rendering. Also note that most background images will need to be brightened up to create a lighting contrast between interior and exterior.

The image can be placed either with planar, cylindrical or spherical mapping. Planar is the easiest to control as you can see it in the walkabout window before Raytracing and position it accordingly. Always make sure the perspective of the image matches that of your interior view by aligning the horizon lines. One disadvantage, though, is that you will have to keep repositioning the background as you change your viewpoint. Also planar backgrounds don’t reflect in shiny objects in your model, rather they show through the object making it appear transparent.

Cylindrical mapping is probably the best to use and will reflect in shiny objects. It’s not usually necessary to map it through 360 degrees, 180 is usually more than adequate as can be seen in the sample drawing. Adjust the altitude so that the horizon line of your image is at the correct level.

Spherical mapping is best reserved for exterior shots and animations as it requires a special spherical image to avoid distortion.

With the image selected and placed appropriately, set the environment background colour to 3 colours which mimic the image. This will ensure you don’t get any horrible cyan reflections in shiny surfaces.

Final Tweaking

Once you have run your final Raytrace, the fun is still not over. It’s time to hit the exposure controls. Accurender has an auto exposure feature which balances out the overall image sometimes leaving it looking a little flat and lifeless.

Depending on whether your viewpoint is looking towards the windows or away from them, you will need to adjust the exposure controls to suit.

There are no standard or suggested values to use as it is purely view dependant. Just remember to use them.

This completes the tutorial.

rev 08.08.2005    ::   For more information visit http://www.accustudio.com/
rev 08.10.2005    ::   Introduction by Daniel Hargreaves

You've finally finished the rendering, but the background doesn't look right and needs to be replaced. Use of the alpha channel is the way to go.

This tutorial describes the use of the alpha channel in AccuRender.

Introduction

An Alpha Channel represents transparency information about an image, on a per pixel basis. This can be very useful with the renderings created with AccuRender.

The following is how I’ve come to use the Alpha Channels of TIFF files which have been generated from a rendering in AccuRender. This may or may not apply to your use; therefore, please regard all of this as a general discussion only, and in no way infer any particular expertise of the author (ergo ME!).

Creating The Alpha Channel With AccuRender

To create an Alpha Channel with AccuRender, in the “Environment” settings dialogue, select “Alpha”, as shown below:

Once the rendering is complete, you need to save your image in a file format that supports the Alpha Channel. My preference is to save it as a TIFF file (Tagged Image File Format) as this is a lossless type image. 

How To Isolate The Rendered Image Using The Alpha Channel

Using Adobe PhotoShop, open the TIFF file which you’ve created. Following is the sample that I’ll use for this demonstration:

Even though it isn’t obvious at this stage, this TIFF file contains an Alpha Channel which consists of all of the transparency information; that is, all of what is not the image that you rendered.

You can use this Alpha Channel as a mask to separate the actual image from the background in order that you can then insert other backgrounds, other images, text, etc.

To do this, proceed as follows.

On the menu bar in PhotoShop, click on “Select” and then “Load Selection”, as shown below:

You will next be presented with the following dialogue box:

The default shown above is fine, so click “OK”. Next, click on “Layer”, then “New”, then “Layer Via Copy”, as shown below:

Alternately, you can use the shortcut keystrokes to do this by holding down your <CTRL> key and simultaneously depressing the letter “J”. You will now have a new layer which contains ONLY the image; the background is not included.

To evidence this, make your new layer active and then turn off the visibility of the Background layer. You will see that only the image remains:

No matter how meticulously you might try to create this by silhouetting, you could never be as precise because the Alpha Channel is done on a pixel-by-pixel basis – simply put, it’s dead on the money!

Creating An Alpha Channel With Photoshop

The following is the way that I have come to create an alpha channel using Photoshop so that you can then mask out the background when you apply it in AccuRender (whether as a material definition or as a decal). It's not difficult to do, but it's also not so easy to figure out if you'd never done it this way before.

Begin by creating a new PhotoShop file and be sure to set it as "RGB" (not grayscale), even if your image doesn't need color. Next, create whatever you're going to create in PhotoShop. Save it as a native PSD file.

Click on the "Channels" palette, and from there, click the right-pointing triangle you see shown below. Next, click on "New Channel" like you see here:

It will default to the following, which is fine - accept it:

You will now notice that it has turned off each of the RGB channels (why this is, I have no idea). Turn all three of them back on. You will now see something like this:

Now click back on the "Layers" palette and make your selection using the ordinary way that you're used to.

In the example above, I simply held down the <CTRL> key and depressed the layer's name which selected everything "active" on that layer.

Now press the <DELETE> key, and you're done: Note that it deleted that selection from the alpha channel; it did not delete anything from the layer itself.

You will need to save the file out in a format that supports an alpha channel, such as a TIFF file, for example.

This completes the tutorial.

rev 03.20.2005    ::   For more information visit http://www.accustudio.com/
rev 08.10.2005    ::   Formatted for AccuStudio by Kevin Lockwood

An advanced tutorial for UVeclipse & 5AMIN

This tutorial covers the need for control of the ambient light in exterior rendering. This is done by the use of a light dome.

Introduction

You have created the perfect model. You click render and the lighting is flat. The shadows have no depth. One way to over come this is to use a light dome to fill in the missing parts of your lighting. Before you jump into this tutorial, it is assumed that you have looked at the UVeclipse Beginners guide and have a good understanding of Accurender lighting. You can find the UVeclipse tutorial by CLICKING HERE.

Because we are focusing on lighting in this tutorial, we will be completely ignoring the background and materials.

In the following text, AR3 refers to AccuRender v. 3.1., UVe refers to UVeclipse Light Dome creator by David Rutten, and 5AM refers to 5AMIN for AutoCAD Program for importing the 5AM file format created by UVeclipse.

If you want to use the same AutoCAD model and 5am file you can download them from the 5AM Tutorial site. The links are provided below.

Model (AutoCAD 2000 format)
blue.5am (UVeclipse light solution)

Setting up the Model

When you first load a model into AR3 and click "Render" You get the default lighting which is similar to the AR3 "SUN". With this light you don't have any control over location or intensity.

The first step in setting up for the dome is to reduce the default "Ambient Light." This is found on the Lighting Dialog by clicking on the "Ambient" button. The default setting is 0.800. You will need to select a very low number like 0.01 or 0.015, you can even turn it off by setting all the way down to 0.0. For this tutorial we will use the value of 0.015. 
 

As you can see the model has already gotten darker. This will let the lights interact with each other. But we still need to add the "Main Light" source. This will allow us to control the light in the scene.

Adding the Main Light

Open up the Lighting Dialog in AR3. Before we add the Main Light, let's enable the lighting zones. Also at this time we can add a zone for the light dome.

Click "Add Zone..." to add your light Zone. We will use this later to control the dome, but for now let's just name it "Dome", and leave it empty. We will place the Main Light in the scene in the default "**Main**" zone.

There are to types of lights that can be used with the dome. The third we will steer away from, the "**SUN**". The default SUN is very powerful and I find it fights with the the dome lights. With this we will look at the "Parallel" and "Spot" Lights. We add these be selecting the "Add" button on the Light Dialog.

The Parallel light behaves very much like the sun. It is a light source very far away and all light is "Parallel" in the scene. You can control just like the the sun with the exception of select a time and location. Modify the Azimuth and Altitude to the the general lighting effect desired. As you can see, with the Ambient almost at zero, the shadows are very black.

By using a spot light set very far away from the model, we can emulate the the parallel light. The problem is a 100 watt light won't make it to the model if it is a couple hundred feet (or meters) from the model. So we need to increase the wattage. Depending on the scale or size of the model and the distance the spot is set is how high we need to set the wattage. For now we will set it to 24,000 watts. We still have the black shadow, but we also get some nice soft light effect on the curves.

Adding the Dome

The first step is to launch 5AM. You will need to load the VLX file and then type 5AMIN at the command line. Choose a 5am file, for this tutorial, we will use "blue.5am." The UVe light solution blue.5am has 49 lights in it. Using a dome around 50 light is the minimum I would recommend. If you have to few lights they have a hard time interacting with each other and the scene, and they really won't contribute, just give you hot spots. To many lights can wash the scene out and adds unnecessary time to the rendering. There are also several other 5am light solution files on the 5AM tutorial site that can set the mood of the rendering. Select the "Center of Light Dome" close the the middle of the model. If you are using a ground plane set at zero, it is best to raise the Z axis of the dome to 12" above your ground plane. This way the lights don't intersect the ground plane. You may also notice in the sample model, that the default AR3 ground plane is not used. I have found that the infinite plane can suck the life out the light dome making more of a challenge to adjust the lighting. Using a 3Dface (or in this case a circle) will make it easier to adjust. Next we will need to set the radius bigger than the model. This is where the "Preview Dome" button comes in handy. The model is a 100' across and almost 50' tall. A dome with a radius of 80' (960 inches) will encompass our model. You can use the radius button or just type the distance in. I have found a good general rule of thumb is your light dome should be about twice the size of your model. When you have every set, click on the "Insert Dome" button.

Adjusting the Dome

Because 5AMIN was written with "Studio Lighting" as its base, the intensity slider only goes to 100. If you delete all of the lights from the dome, increase the lighting to 100 may improve it some, you still don't get very satisfying results. 

Because the lighting is not satisfactory, once again we will delete the UVe lights in AR3. The nice thing about 5AM is you can override any of the settings by typing directly in the edit box. Where you see the "100" under the "Light Intensity" type in 5000. This number will change the wattage of the accurender light. We also have raised the Z to "12" to get the lights off of the ground plane. We need a value per light to work with the scale of the model. 5000 is a good starting place for most exterior models. After you insert the light dome, remember to put the lights in to the "Dome" light zone. This will make it easier to do small adjustments later on.

The lights from the dome are blending better, but each one is casting a hard edge shadow. If you increase the antialiasing to High (or Highest) and select "Soft Shadows". This will continue to improve the over all lighting and shadows in the scene. Of course it will also slow down the rendering time. But the time spent is worth the wait. 

Putting it all together

The last step is to turn the main light. Before doing a final render, let's turn off the soft shadows. This will give some of the speed back and we are still in a testing mode.

If you find that the light dome shadows are still over powering, you can edit the zone.

One thing to take into consideration is we have 49 lights at 5000 watts each. So small adjustments will make a difference. For this model I have lowered it to 0.040. You will see changes in the light level with 0.01 adjustments.
 

With the light levels set, we can now do a final rendering with soft shadows turned on and antialiasing set to Highest. You can see how the ambient light is now a soft blue. 

Summary

Adding, and adjusting the Main Light along with the Light Dome is all part of preparing your final exterior scene. The two main things that will take most of you time in preparing a rendering is materials and lighting. Hopefully you see the time invested in lighting will give you the high end results you are looking for.

This completes the tutorial.

rev 8.15.04    ::   For more information visit http://www.accustudio.com/
rev 8.13.07    ::   Updated links

UVeclipse is a program created by David Rutten. The following is clipped from the UVeclipse home page:

"The purpose of UVeclipse is to lubricate the tedious task of a lighting setup prior to rendering. In order to render an image in a photoreal context you need lots of lighting factors to approach the real thing. In most cases photons are colliding with objects all over the place and adding 2 spotlights to your scene isn't going to make up for that. Some platforms feature skylights but often these lack the necessary colour controls which would make them really useful."

"UVeclipse can generate a realistic lighting setup within seconds, based on easy to get image data. Lightdomes are used to simulate a light-casting environment, including coloured, directional shadows and hotspots."

The counter part is to use an importer with your rendering The focus of this tutorial is to work with AutoCAD and Accurender 3. The latest version of 5AMIN can be downloaded from the ArchSymb web site , just click on the "Bonus & Free Stuff" link. You can also visit the MarketPlace > UVeclipse for samples and the programs. Version 2.2.3 is the latest version.

Get an Image

The first thing you will need to do is get an image. The Exchange > Textures > Backgrounds is an excellent resource for UVeclipse images. For this tutorial I used the Grace Image. This can be found under Backgrounds/Mirror maps. Basically you can use any panoramic image, it is best to select one that you can use in your environment in Accurender.

UVeclipse also comes with a default image which can be used also for creating your light solution.

Launch UVeclipse

Launch the UVeclipse program. If you did a standard install, you can find the icon on your desktop. Otherwise, you can find it under your Start button, Programs, UVeclipse.

By default the program will launch the "Open new enviroment image" dialog. If you already have an image loaded or clicked on Cancel, you can bring it up again by clicking on the Folder icon.

Navigate to the location were you saved your image and click Open.

In this tutorial I’m going to talk about scaling masonry bitmaps to get correct sizing. In particular scaling of elements like bricks, blocks, pavers, CMU’s, and similar items.

Many times we get hold of a great photo of some material but have no idea about how it was photographed. How far away was the camera? How big are those suckers in the real world? You need to know this to be able to get correct scaling of the photographed material onto your CAD based objects. Frequently people just guess the scaling but most times there is a better and more accurate way to get it right.

First off we’ll look at masonry patterns. Once you understand the basic patterns in common use and the modular sizes used in various countries, you will know how to treat your bitmap.

Secondly I’ll discuss what’s required to fix up the errors and shortcomings that commonly appear in photographed materials – even those that are professionally prepared. Lastly we’ll look at how to crop your bitmap and create a new AccuRender material so you’ll get a near perfect result when you use it.

Bricks

While there dozens of ways to lay bricks, they are generally laid in a few standardized patterns, known as bonds. There are 4 main bonds used in face brickwork.

• English bond – each alternate course shows brick faces only, the other courses show brick ends only. See diagram.
• Flemish bond – each course consists of alternating faces and ends,
  with each successive course offset by 50%. See diagram.
• Stretcher bond – also known as running bond. Each course is laid one half brick along from the previous course. Only brick faces are seen. See diagram.
• Soldier bond – bricks are laid in a grid pattern with no offsets, so that all joints line up in straight lines. Can be laid horizontally or vertically, either faces only or ends only may be seen.

Generally speaking, older or period buildings will be laid in English or Flemish bond (which was suitable for solid walls), while modern buildings employ Stretcher bond, or occasionally Soldier bond for feature panels. These are suited to cavity walls.

Although brick setouts have varied greatly over time and between cultures, we can nonetheless establish standards that comply with modern usage.

U.S.A. Standard The standard U.S. modular setout is based on a module of 8 inches. This means 1 brick length plus mortar joint is 8 inches, and 3 courses in height including mortar joints totals 8 inches. A standard brick is 7 5/8” long x 2 ¼” high x 3 ¾” wide. U.K. Standard The current U.K. metric standard varies a little from the traditional Imperial setout, and the module is now 225mm in length including mortar joint per brick, and 75 mm in height including mortar per course. The Imperial module was 9 inches in length and 3 inches in height. A standard brick is 215 mm long x 102 mm high x 65 mm wide. Australian & New Zealand Standards This metric standard is based on a repeating module of 2400 mm x 600 mm. 10 bricks in length including mortar total 2400 mm and 7 courses of bricks including mortar total 600 mm in height. One course including mortar is therefore 85.7143 mm high and one brick including mortar is 240 mm long. A standard brick is 230 mm long x 75 mm high x 110 mm wide.

Concrete Blocks(CMU)

Like bricks, concrete blocks have been made in many forms over the centuries, but are now made in standardized sizes and are laid in predictable patterns. Also known as CMU (for concrete masonry unit) in some countries, they may have a smooth face, a grooved face, or a rough face created by mechanical splitting of the manufactured units.

These units are usually laid in stretcher bond and occasionally in stack (vertical joints) bond.

U.S. Standard

Standard U.S. module is 8” long including mortar x 8” high including mortar x 8” wide.

U.K. Standard

The current U.K. metric standard is 450 mm in length (equal to 2 bricks) including mortar joint per unit, and 225 mm in height (equal to 3 bricks) including mortar joint per course.

Australian and New Zealand Standards

This metric standard is based on a repeating module of 400mm x 200mm. 1 block length including mortar totals 400mm and 1 block course including mortar totals 200mm in height. Sizes and thicknesses vary, but are generally multiples of 200 mm.

A common block size is 390 mm long x 190 mm high x 190 mm wide. Thus 6 block lengths equal 10 brick lengths, and 3 block heights equal 7 brick courses.

Paving Bricks and Tiles

Modern paving bricks and tiles are made in predictable sizes. While patterns are many, but if we know the unit size we can calculate the layout dimensions.

U.S. Standard

Common sizes are 8” long including mortar x 4” wide including mortar. Also 6” x 6” and 12” x 12” are common.

U.K. Standard

Common sizes are 200 mm long including mortar x 100 mm wide including mortar. Also 300 mm x 300 mm and 400 mm x 400 mm are common.

Australian and New Zealand Standard

Common sizes are 200 mm long including mortar x 100 mm wide including mortar. Also 300 mm x 300 mm and 400 mm x 400 mm are common.

Diagonal Setouts

Pavers and bricks are sometimes laid in diagonal, herringbone, or basketweave patterns. By knowing which shape has been used it’s possible to work out the correct usage for the bitmap. Two situations are common – square modules laid diagonally or rectangular modules laid diagonally. Knowing all this, bitmaps can be corrected to suit various CAD systems and national standards.

Fixing Bitmaps 

Most bitmaps, including those professionally prepared, require some fixing before they can be used. In this tutorial I am using Photoshop for corrections but most paint programs operate in a similar way, although they may not have all the bells and whistles of Photoshop.

The usual problems with bitmaps are rotation errors, lens distortion, angled shooting effects and exposure correction. Once these problems are fixed the bitmap can be cropped to suit our purposes and made into a seamless material.

When first opening an image I find it often pays dividends to use Photoshop’s Image/Adjustments “Auto Levels” and/or “Auto Contrast” tools. Although not perfect they can often remedy an imperfect image very quickly. If they don’t help much you can always adjust manually where needed.

You need to check that the image has not been rotated, or indeed that the camera was not out of alignment with original object being photographed. You could try turning on the grid to check the image’s alignment. It’s useful to zoom the image up to full screen to see more detail. Hit the Tab key to turn off all dialog boxes so just the image is visible. If it’s out of level here’s what to do.

Photoshop has a natty little item called the “Measure Tool” which you’ll find on the eyedropper flyout. Use it this way – pick a point on the image and then pick a second point that should be either directly horizontally opposite or directly vertical above/below the first point. In other words pick two points on the image that should be either horizontal or vertical to each other if the image was not distorted or rotated.

Now go to Image/ Rotate Canvas/Arbitrary. You’ll find that Photoshop has recorded the rotational error for you. Hit O.K. and magically the image is automatically corrected and made level.

If the image is still out of whack or distorted in some way – say for example the brick or tile joints don’t line up as they should, try using the Edit/Transform tools to correct any stretching or perspective errors. Now we come to cropping the image. I suggest you make a copy of the original before cropping.

The aim of this cropping is to create an image that tiles seamlessly when it’s applied over a large area. Ideally, what we want is an image that starts in the CENTER of a mortar line on the left edge and finishes in the CENTER of another mortar line at the right edge. If the image is for walling, we also want a FULL mortar line at the base edge and NO mortar line at the top edge. If the image is for paving, we want to crop in the CENTER of a mortar line at the base edge and in the CENTER of a mortar line at the top edge. It’s best to crop your image to the maximum size you can, and also remember to zoom up to full screen to have the best possible view of exactly where you’re cropping, as you cannot zoom after selecting the cropping tool.

NOTE – always crop your image so you have a FULL number of bricks/tiles on one row. Count them up and make sure there is a row of full ones. It’s O.K. if there are two half bricks/tiles, one at each end, because that still totals up to a row of full ones. It doesn’t matter how many there are in the total, however.

NOTE – always crop your image so there are a FULL number of brick/tile courses. It doesn’t matter how many so long as they are full courses.

Now let’s work a real example. The image below is a download from the BeldenBrick site at http://www.beldenbrick.com/. Note that it has a mortar line along the top, but almost none along the base. That’s fine for paving but not for walling. Why not? Because you don’t want a line of mortar running along the top of a wall – that’s why.

By having a full mortar edge along the bottom and none at the top of each tiled patch you create the impression of consistently repeating mortar lines till you get to the top, where it finishes neatly as brick without mortar. The left and right edges are a compromise. By cropping an image in the center of vertical mortar lines you achieve correctly tiled patches running left to right. This is a minor problem on exposed vertical corners such as pillars, where you’ll see a narrow line of vertical mortar where there should be none, but there’s no easy workaround for that.

Here’s the original bitmap. Note there are several problems with it. It’s too dark; it has no mortar line along the base; it doesn’t contain a full number of bricks left to right; and it has a half line of mortar along the top. Often times, just rotating or flipping the bitmap to get the mortar to the bottom, is a good starting point.

Now here’s our new bitmap, with all those problems fixed. Save it on an AR3 path.

NOTE – keep a written record of the number of full bricks across and the number of courses vertically – you’ll need that later.

Now the next issue is to create an AccuRender material from our new bitmap.

Let’s say we want to use this image for a metric sized brick wall and piers for a project in the U.K. We know from our previous work that brick modules in the U.K. are 225 mm long x 75 mm high. We also noted that our new bitmap is 8 bricks long x 14 courses high, so we want it to render at 1800 mm wide (225 x8) and 1050 mm high (75 x 14). Open AccuRender, create a new material, and select our new bitmap as the map.

Click on the Main tab and unlock the fixed ratio by picking on the padlock symbol and set the map size to X=1800 and Y=1050 (assuming you have your units set to millimeters). You may need to adjust the size of the preview cube/sphere to see the map clearly. Now save your new material. Refer to image below.

Below is a test rendering showing U.K. sized piers and wall with this material applied. Everything fits as it should and all brick joints are correctly located.

Another example. Let’s say we have a brick bitmap that is 12 bricks wide and 28 courses high for use on U.S. walls. We know from our previous work that the U.S. standard brick module is 8” long (1 brick) x 8” high (3 courses). Therefore we make our bitmap 96” wide (8 x 12) and 74.6666” high (8 x 9.3333). Note that you could also crop the bitmap to be 27 courses high for simplicity’s sake. Then your calculation would be 72” high (8 x 9). Note that you should also remake the material after cropping the bitmap, if you do that step.

Another example. For a brick bitmap having 7 full bricks width and 14 courses height, for use in Australia or New Zealand, the AccuRender material settings would be X = 1680 (240 x 7) and Y = 1200 (85.7142 x 14).

Concrete Block (CMU) Calculations

The issues here are exactly the same as for bricks. A CMU bitmap should be cropped in the same way as described for bricks. Create a new material in the same way.

Worked examples. A CMU bitmap having rectangular blocks twice as long as they are wide could fairly be presumed to be a 16” x 8” unit in the U.S.A. If it has 9 full block lengths and 7 full block widths showing, then the AccuRender material settings would be X = 144 (16 x 9) and Y = 56 (8 x 7) - assuming inches is set as the AccuRender unit.

As an example in the U.K., let’s say you have a bitmap that you want to use for block walling. The bitmap shows 11 full blocks in length and 9 full blocks in width after straightening and cropping. The U.K. module is 450 mm long and 225 mm high (refer above). Therefore the AccuRender map settings would be X = 4950 (450 x 11) and Y = 2025 (225 x 9) – again assuming the AccuRender units setting is millimeters.

Paving Bricks and Tiles

Where paving bricks or tiles are square or rectangular, and are laid horizontally or vertically, the settings are just the same as for wall bricks and blocks.

Diagonal Setout

Where the units are laid out in a diagonal, herringbone or basketweave pattern things are a little more complicated, however. Standard formulas can be applied to these cases to solve most situations. It’s useful to understand that all these setouts are formulated around multiples of √2 (1.4142) where the tile size is either 1 x 1 units or 1 x 2 units in dimension, and this fact forms the basis of all calculations.

For diamond shaped setouts where the units are square, each repeating module of 4 tiles is 2 x √2 (2.8284) units long and 2 x √2 (2.8284) units wide, where each tile is 1 unit x 1 unit. Each tile measures √2 (1.4142) units corner to corner. Refer to diagram below. Bitmaps should be cropped to contain only full multiples of these units.

As a worked example, let’s say you have a bitmap composed of square paving bricks. You want this material to render as 300 mm bricks on a metric based project in the U.K. The bitmap when corrected and cropped shows 8 full bricks horizontally (4 full units) and 6 full bricks vertically (3 full units). Using the formula, the calculations for the AccuRender material are: X = 4 x 2.2824 x 300 = 2738.8800 and Y = 3 x 2.2824 x 300 = 2054.1600.

For a U.S. project where the pavers are to render at 12” x 12” and the AccuRender units are set to inches, the calculations would be X = 4 x 2.2824 x 12 = 109.5552 and Y = 3 x 2.2824 x 12 = 82.1664.

In the case of rectangular materials, the same principles apply, but with a slight twist. For basketweave setouts, each repeating module of 8 tiles is 4 x √2 (5.6568) units long and 4 x √2 (5.6568) units wide, where each tile measures 2 units x 1 unit. Refer to diagram below. Bitmaps should be cropped to the corners of full multiples of these units.

As a worked example in the U.S. where the tiles must render at say 8” x 4” each, and the corrected bitmap is 5 full modules long and 3 full modules wide, the AccuRender material settings would be X = 5 x 5.6568 x 4 = 113.1360 and Y = 3 x 5.6568 x 4 = 67.8816. This assumes the AccuRender units are set to inches.

For a metric example using the bitmap above, and where the tiles must render at say 300 mm x 150 mm, X = 5 x 5.6568 x 300 = 8485.2000 and Y = 3 x 5.6568 x 150 = 2545.56, where the AccuRender units are set to millimeters.

For herringbone setouts where the units are rectangular, each repeating module of 2 tiles is 2 x √2 (2.8284) units long and 2 x √2 (2.8284) units wide, where each tile measures 2 units x 1 unit. Similarly, each tile measures √2 (1.4142) units corner to corner. Refer to diagram below. Bitmaps should be cropped to contain only full multiples of these units.

The calculations for a bitmap of this type are similar to the other patterns. As an example, for a metric project in the U.K. where each brick/tile has to render at 200 mm x 100 mm, and the bitmap shows 11 full modules horizontally by 8 full modules vertically, the AccuRender material settings would be X = 11 x 2.8284 x 100 = 3111.2400 and Y = 8 x 2.8284 x 100 = 2262.7200.

As a practical example, consider the bitmap below. Apart from the usual problems, it has one more – the pattern does not repeat systematically. In the right hand portion there is either a laying error or a deliberate doubling up of some components, which upsets the symmetrical patterning.

To rectify this problem we must first identify where the module repeats fall within the image and so decide where to crop it. The white lines show where we will crop.

After cropping and adjustment, we must also do some further editing. For this bitmap to work successfully the various brick colors must repeat both horizontally and vertically at the seams. All “A” areas must be the same, as must all “B” areas and so on. Some selection with the lasso tool and some mirroring, cutting and pasting will fix this problem. The final bitmap is shown below.

In the image below the new bitmap has been applied as a paving material. Although a little repetitive due to the small sampling area that was available, it repeats seamlessly and all edges appear as they should.

Other Materials

The methods shown here can be extended to many other types of materials that have been photographed. In fact anything that is composed of identifiable units can be used to create a new material that is correctly scaled. Examples such as parquet flooring; glass bricks, roof tiles, shingles, sheet roofing, floorboards and similar items would be suitable for this purpose.

Note – a special thanks to Daniel Hargreaves of MPI Architects for valuable help with U.S. standards.

After your animation frames are rendered, and you inspect the finished result, you might find the need to add or delete a few frames, or otherwise tweak the motion a bit. This tutorial covers an assortment of techniques to modify and reassemble your animation into a finished product.

Introduction

Once you have created your animation, you may find yourself faced with several questions:

• If you’ve added or deleted frames, how do you fix the frame numbering to allow for those changes?
• What if you want to add a gradual fade-in from black screen at the start, or a gradual fade-out to your company logo at the end?
• What if you want to freeze the action somewhere during theanimation?
• What if you want to combine some frames from animation A then a few from animation B, before adding all frames from C and just a couple from D?

This tutorial is about those kinds of issues. It is assumed that you already have AccuRender or you wouldn’t be reading this tutorial, and with the sole exception of coMOTION, this discussion has been limited to programs that are available for free.

In the following text, AR3 refers to AccuRender v. 3.1., coMOTION refers to coMOTION Animation Extensions for AccuRender, WinMorph refers to WinMorph v. 3.01., and Bink refers to RAD Games Tools Bink v. 1.2i.

Frame Numbers

When you create your frames (total no. = N) in an AR3 or coMOTION animation they will be numbered consecutively beginning usually with frame 0000 and ending with frame N-0001 (N minus 1). It’s important to understand that the first frame is not 1, but zero.

Animation compilers such Bink will search only for consecutively numbered files within a directory, so if you’ve deleted frames or if there’s a gap in the number sequence, the compiled animation will start with the lowest numbered frame in the selected sequence and end at the first gap. That’s a problem right there because you’ll be missing whatever comes after the gap.

Now you could manually re-number the remaining frames, but that might be an enormous task, and anyway there are better methods. One very useful tool for this purpose is ReNum, which can be downloaded from either AccuStudio at http://www.accustudio.com/marketplace/fm_freeware.htm or directly from the authors at http://www.gromada.com/temp/renum130.exe.

Renumbering Frames

ReNum is an intelligent tool that can understand nuances in human numbering systems. That means ReNum understands things like this: - a collection of files numbered 089, 075, 076a, 076b, 078f, 123, 066c would be understood and put into correct order. If you chose to renumber and rename them say “ZEN000” you would get ZEN000 through to ZEN006 in the correct numerical sequence of the originals.
NOTE – All frames should be the same size and of the same file type.

Adding Frames

If you need to add extra frames into your animation, then depending on how many frames, there are 2 ways to do it with ReNum. If it’s a small number to be added, or they’re just here and there, you could use an alphabetical method. If it’s a large number to be added then a numerical method is easier.

ALPHABETICAL METHOD

The alphabetical system uses “a, b, c” format. ReNum understands that 16a comes after 16, and that 32w comes after 32 but before 33. Similarly with aa, bb, and so on. Because you must rename frames manually in this method, it’s only suitable for small additions however.

It’s a 2-step process. First pick the frames to be inserted and rename them as per the above method. Then include them in your total selection to insert them into the overall series in the right place. Shift-pick will grab a consecutive range of files, and Ctrl-pick will grab only the files you pick. When you renumber the selection, all files will be renumbered sequentially (but without the a,b,c’s).

Let’s say you have 5 frames to add after frame 077 in your 100-frame animation. You’d name them 077a, 077b, 077c, 077d and 077e. You then pick all frames and renumber. The new frames will be inserted after the old 077 but before the old 078, and the total sequence will increase by 5, making the new sequence 000 to104.

NUMERICAL METHOD

The numerical method entails renumbering groups of frames. The sequential groups that result from this can then be all collated together for compilation into a complete animation. This method is more fully explained below in the COMBINING CLIPS worked example.

Deleting Frames

Why would you want to delete frames? There are several reasons why you might. If an animation turns out to be too long-winded, or you want to make a shortened demo, or if there are faulty frames needing replacement, or where frames have been duplicated.
Duplicated frames can occur in coMOTION animations that are cyclic or repeating in nature.

coMOTION EXAMPLE

Let’s say you’ve got an oscillating object which cycles over say 100 frames. In the coMOTION setup you might have the object centered on frame 000, then reaching maximum left twist on frame 024, centered again on frame 049, reaching maximum right twist on frame 074, then finally centered again on the last frame, i.e. frame 099.

Now when you run your rendering, assemble your frames, and create a repeating animation it won’t look quite right – there’ll be a glitch because frame 000 and frame 099 are duplicated. The animation will falter when it reaches the start/end point in the cycle because two successive frames are in the same twist position. The solution is to remove frame 099 before assembling the animation.

Deleting Frames with ReNum

ReNum allows you to select any frames in a series and delete them. You can then choose either to replace the missing files or to renumber the entire series to remove the numerical gaps that now exist.

ReNum also allows you to select individual frames, or every Nth frame. For example, you could select every 5th frame, or every 10th frame and save just those to create a shorter, more compact demo version of your full animation. Incidentally, ReNum offers you the choice to keep or delete the original frames when you perform these kinds of actions.

Also you have the choice to rename and renumber just the selected files only. This makes it simpler to distinguish the frames of the full version from the frames of the compact version. If you select the renumbering option your new frames will now be numbered consecutively, ready for compiling directly as the new animation.

Insert / Append with ReNum

Insert allows you to add a selection of files to an existing group, or simply inserts the selection if there are no preselected files. If you pick an insert file that is part of a sequence, then ReNum detects this fact and you will be offered the choice to insert as many of the files in the (non-broken) sequence as you wish by picking from a dialog box. The default will show them all. ReNum calls these files a “sequence” and treats them as a group.

Append will allow you to add a SINGLE file onto an existing group and will compel you to renumber the new group that’s created.

Reverse Frame Order

ReNum can do this too, but why would you want to reverse the numerical order of your frames? A couple of possibilities come to mind. If you’ve drawn your spline paths in the opposite direction to what you intended and your animation runs opposite to what you want, reversing the frame numbers will correct the problem. Of course you could reverse the spline paths and re-render the frames, but this way there’s no need to burn the rendering time again. Another example could be something like an oilfield pump where the piston mechanism travels backwards and forwards, over and over. Just render one half-cycle, copy and reverse-number the frames to complete the cycle. Then create a repeating full cycle as your animation. Same idea with windshield wipers, and so forth.

Creating Fade-ins, Holds, and Fade-outs

FADE-INS are used as introductions or lead-ins to an animation. You could fade in from a white screen (or any color you like) at the beginning. This gives a smooth start to the animation and alerts the viewer that something is about to happen so they had better pay attention. The length of this lead-in is a matter of taste but usually around 1 second is enough.

HOLDS are freezes or sequences where a particular image stays on screen for a fixed amount of frames without changing. Why would you want this? Examples would be where you need to give the viewer enough time to read a written message, or where you want to retain an image for impact – maybe your company logo, or a description about the animation or the project it’s showcasing. Screen time will depend on the complexity of your image – you must allow enough time for slow readers to absorb the complete message.

FADE-OUTS allow a graceful exit at the end of the animation. Again you can fade out to black (or any color) or you can fade out to a graphic of some kind. Generally 1 or 2 seconds is about right.

WORKED EXAMPLE

In this example we will use WinMorph and Bink to create an animation showing fade-in, hold, and fade-out techniques. The general idea is to use Winmorph to create 3 short morphed sequences of the fade-in, hold, and fade-out stages then to use Bink to combine them into a single movie.

First use your image-editing program (Photoshop or whatever) to create 3 images at the size you intend for your animation frames – 1 x black, 1 x mid-gray, and 1 x white at 320 x 240 pixels or whatever size you are using. These images can be reused in other animations any time.

Next get hold of or create, a logo, image, photo, or some kind of bitmap of the same dimensions as the other images you just made. Use this for the HOLD sequence.

Open Winmorph and select File/ New Morph project (or pick the yellow page > page icon). You now choose your starting and ending images for the first sequence. I’ve chosen “320_240_white.jpg” to start and “320_240_intro.jpg” to end. Then pick the CHOOSE button to move to the next stage. Refer to Image 1.

Now choose Morph/ Options. I’ve chosen AVI as the output type, set 25 frames, and a 1 second duration. File name is Part1 (this becomes significant later). For compression options I’ve selected Full Frames (uncompressed). Now O.K your choices and select Morph/ Start Morphing (or pick the yellow/cyan icon) to begin generating the file. You can view it when completed to check that it’s correct.

Repeat the process for Part2 but now select “320_240_intro.jpg” as both the starting and the ending image. Set 75 frames, and 3 seconds duration this time. Because both images are the same, we will get 3 seconds of animation where the same image remains fixed on the screen – just what we want.

Same again for Part3, selecting “320_240_intro.jpg” as starting image and “320_240_black.jpg” as ending image. Set 50 frames and 2 seconds duration for this one. Now close Winmorph and open Bink.

Go to the directory where you saved your AVI’s and highlight Part1.AVI, then pick the “Bink It” button. Bink realizes that the 3 consecutively named files are part of a sequence and asks if you want to treat the sequence as one single animation. Answer Yes then pick a name for the new file. Accept the .bnk format for now and pick the “Bink” button. Your new joined animation is now created. Save it.

Now select your new .bnk file and pick on the “Advanced play” button. The new dialog box offers several choices. The “Make EXE” button on the right is used to make a self-loading and self-running animation Bink file that will run on any machine and any platform.

Now have a look at 3parts.exe

With your new .bnk file selected pick on the “Convert a file” button. The dialog box you now see offers the choice to convert your assembled file into several formats. You can convert it into an AVI or into single frames of several types. Depending upon how you are rendering your main animation file, pick an appropriate format and save.

ANOTHER WAY

As an alternative to the above process, Winmorph offers other choices for direct output of each morphed sequence. You can save to .AVI format, .MPG (mpeg) format, or single frame .BMP output. There are choices available to control image size and quality, etc. Assembly of your final animation file then follows in the usual way.

Morph Variations

As a variation on a HOLD sequence, your image might do all kinds of interesting things while it remains on screen – text might change color or become reversed, photos might go to grayscale and come back to color, things may distort, stretch, or rotate. The Winmorph program makes all these things possible. Check out the Warp possibilities of Winmorph for distorting images.

Combining Clips

After rendering your various frames you need to assemble them into finished animations. Suppose you want to combine:

• 55 consecutive frames from animation A as a fade-in.
• 11 random frames from animation B.
• All 1000 frames from animation C.
• 33 more frames from animation B.
• 99 consecutive frames from animation D as a fade-out.

Step 1 – Open ReNum and select the 55 frames from “A” and renumber them as say, ALPHA 0000. Saving to a different directory is a good idea. Keep the old frames for now. These new frames will be saved as ALPHA 0000 to ALPHA 0054.

Step 2 – Select the 11 random frames from “B” and renumber them to this new directory as ALPHA 0055. Their new names will become ALPHA 0055 to ALPHA 0065.

Step 3 – Select all frames from “C” and renumber them likewise as ALPHA 0066. Their new names will become ALPHA 0066 to ALPHA 1065.

Step 4 – Ditto for the 33 frames from “B”. New names will become ALPHA 1066 to ALPHA 1098.

Step 5 – Ditto for the 99 frames from “D”. New names will become ALPHA 1099 to ALPHA 1197.

Output Options

You may choose to use Bink to compile your animation.

To do this, open Bink and pick any one of the new frames. Pick the “Bink it” button. Bink recognizes that it’s part of a sequence and asks if you want to load them all. Reply Yes, then pick the “Bink” button in the next dialog box. Accept the .bnk format for now and save your new animation. Bink will select all 1198 frames. Your .bnk file can now be converted to an AVI or to a self-running EXE as described in the fade-out example above.

Alternatively, you might wish to output your animation as a Flash file, or you might use one of the many freely available compilers to compile your animation.

Summary

Adding, deleting, and duplicating frames, together with splitting, joining and tailoring clips is all part of preparing your final animations.

There are many expensive and exotic renderers and animation compilers out there in the marketplace, but hopefully this tutorial has demonstrated that you can still get a great result without them.

This completes the tutorial.

rev 4.28.08   ::   For more information visit www.accustudio.com

This tutorial is an introduction to simple AccuRender animation techniques. AR3 is used here as an abbreviation and refers to AccuRender v.3.1. It is suggested that the reader refer to the AccuRender help files and the AccuRender manual for further explanation of concepts where necessary.

Paths

In a similar way to other animation software programs, AR3 uses the concept of a physical “path” to define a route for objects to move along during the course of an animation. AR3 also uses path length, in conjunction with the number of frames in an animation, to determine the rate of travel through the scene.  The number of frames in a single animation sequence is referred to as the frame count.

Although AR3 has no acceleration or deceleration ability, by combining sequences having different combinations of path length and frame count, the appearance of greater or lesser speed can be achieved.

Each camera in an animation may be assigned to a path or may pivot around a single point. Paths can be assigned to multiple cameras. Paths MUST be AutoCAD splines. Splines can be created in two different ways - by use of the SPLINE command or by the splining of polylines.

SPLINE METHOD - By invoking the AutoCAD SPLINE command, splines can be drawn to create suitable paths. Once drawn, spline vertices can be manipulated by the use of GRIPS. Smoothness of splines is controlled by the SPLINESEGS setvar, with a default value of 8 and a maximum value of 32.

POLYLINE METHOD - Polylines can be drawn to create suitable paths. These polylines (plines) are then smoothed by the PEDIT/ SPLINE command. Note that this command creates a splined polyline - not a spline. The SPLINESEGS desired value should be set prior to splining the pline. Again GRIPS can be used to adjust vertices or to manipulate the pline. Once the path is correct, these splined plines can be converted to splines by invoking the SPLINE/ Object command and picking the pline. Performing a LIST upon the path will verify that it is now a spline object.

Many users find splines difficult to draw with accuracy and to manipulate, and so the splined pline method may be easier to set up and to adjust.

Animation Types

There are 4 basic types of AR3 animation:

• Walk Path - create new or pick existing path
• Orbit Path - create new or pick existing path
• Spin Path - create new or pick existing path
• Target + Walk Path - pick 2 x existing paths

WALK PATH

The camera moves along the path, always looking at the path ahead, like a person walking.

ORBIT PATH

The camera moves along the major path, always looking at a fixed target - often creating the effect of orbiting around a central point. You will be prompted for a target object when the orbit path is selected. Either an AutoCAD point object or a short spline (minor path) can be used as the target.

SPIN PATH

The Spin Path format is virtually the reverse of the Orbit Path format. The camera is rotated around a central point, or travels along a minor spline path, while the camera’s aiming point follows along the major path further out from the center. This type of animation is suited to creating a panorama.

TARGET + WALK PATH

This format allows the camera to follow along one path, while its aiming point follows along another path. This is suited to cameras that change viewing direction as they move along the path.

Additional Controls

Several additional controls are available for the animation:

LENS LENGTH

The starting and ending Lens Length can be set differently, so that the visible field of view changes during the course of the animation. Lens parameters are analogous to a standard SLR camera lens.

2 POINT PERSPECTIVE

Two-point perspective control is available to eliminate the vanishing point distortions that occur when the viewing direction is not parallel to the XY-plane.

EXPOSURE

Standard tone operator controls are available.

RECALIBRATE FRAMES

This control can help to minimize animation flicker caused by varying exposure levels throughout the animation.

OUTPUT

Rendered output takes 3 possible forms - AVI full movie or Single Frames as finished files, or you can generate a quick shaded AVI file from the Walkabout window. The AVI full movie option offers the choice to select the preferred video compressor and then render a finished AVI movie. The Single Frames option offers the choice of JPG, BMP, TGA or TIFF output - one frame at a time. The Single Frames option can offer many advantages. Faulty or imperfect frames can be re-rendered, transitions are more easily created, and in the event of power loss or system lockup, all output is not lost. However, for small or non-critical animations AVI may be your choice of output.
As a third option, or maybe just to check your work, you can generate a quick shaded view AVI by loading the scene into the Walkabout window. If you then select Render Frames/ Preview/ Record you are prompted for a name and the number of frames you want to record. A simple shaded AVI without background or ground plane is then generated.

Animation Speed

What is speed? It is UNITS OF MOTION relative to UNITS OF TIME. In simpler terms, how far in how much time?

AR3 controls the movement of an animation sequence by dividing the length of the major path by the frame count. For example, if you have a Walk Path of 100 ft and a frame count of 50, AccuRender will move 2 ft along the path each time before rendering the next frame. In other words, 100 ft of path is equally divided into 50 frames, 100/50 = 2.

FRAME RATE

The next consideration is frame rate. Animations are, like cartoons, simply a series of still shots passing by so fast that it seems like movement is really happening. But how fast is fast enough to be believable, and how slow can you afford to go?

These are some industry standards as guidelines. Frame rate is expressed in frames per second (f.p.s.). Hollywood movies = 24 f.p.s. , NTSC (North America & Japan) video = approx. 30 f.p.s. , PAL/SECAM (Europe & Asia) video = 25 f.p.s. Generally any motion below about 12 f.p.s. appears jerky, while above 30 f.p.s. is not necessary. Reasonable frame rates for animation range from around 15 f.p.s. - 20 f.p.s. The higher the frame rate, the smoother the motion appears, but the more frames have to be rendered.

If you are aiming to produce broadcast quality animation, you must maintain the standard frame rates mentioned above, as well as standard frame sizes.
These are some typical values: -

MPEG-1 (NTSC) 352 X 240 pixels
MPEG-1 (PAL) 352 X 288 pixels

MPEG-2 (NTSC) 720 X 480 pixels (maximum), also 704 X 480 and 352 X 480.
MPEG-2 (PAL) 720 X 576 pixels (maximum), also 704 x 576 and 352 x 576.

Relating to the Real World

All this information can be used to calculate an animation where things move at the speed they should, and thereby look correct to the viewer who is accustomed to the real thing in the real world. Some basic mathematics is required, but it isn’t very difficult. The beginning point is to calculate how many frames to render - it depends upon your final output use of course - but when you know that, the rest is easy.

Sources of Information

Many users may have no idea at all about how fast things ought to move in the first place. How do you solve that? There are 3 ways. Below is a table in both metric and imperial units showing speeds of some common activities - that’s the first way. K.P.H. = Kilometers per hour. M.P.H. = Miles per hour.

SIMPLE EXAMPLE 1

Let’s say you want to move through your street scene at the speed of a police cruiser prowling an inner city block. From the table above we know we want a speed of around 15 m.p.h. Our 3D street scene is 350 ft long and we’ve got a camera path of say 300 ft. running through it. Another way of looking at things is to say 15 m.p.h. = 5280 ft x 15 = 79,200 ft spread out over 3600 seconds (1 hr.) or 22 ft per second. A path of 300 ft will take 13.636 seconds to pass along at 22 ft per second. So 13.636 seconds of animation at 20 f.p.s. will require approximately 273 frames to be rendered. So let’s set 275 as the frame count to be sure we got it all in the can.

The second way to get information is the Internet.

SIMPLE EXAMPLE 2

Let’s say you want to animate your camera to move around a running track at the speed of an Olympic sprinter. How fast is that? Go for example to the Guinness Book of Records site, look up sports/ athletics and check the world record time for say 400 meters. Let’s say, for simplicity’s sake it’s 40.0 seconds flat. O.K. that’s 400 meters in 40 seconds = 10 meters in 1 second (average).

If we’ve got a standard Olympic oval running track of 400 meters, (and a camera path of 400 meters), that’s going to take 40 seconds for a full circuit. 40 seconds of animation at 20 f.p.s. will need 800 frames total. Now 40 seconds of just one activity is a very long time in animation terms, so let’s have just 10 seconds - that’s plenty. 10 seconds at 20 f.p.s. will require 200 frames to be rendered. Now you’ve got 2 options here - just render 200 selected frames, or make a new path that will take 10 seconds to pass along.

The third way is actual measurement. There are some things you can time yourself with a stopwatch or just a simple wristwatch. Let’s say - as a far out example - you want to know how fast someone in a wheelchair moves, or how fast an animal can run. All you’ve got to do is time how many seconds it takes for the subject to get from point A to point B. When you know the distance from point A to point B you’ve got your answer - X feet in Y seconds or X meters in Y seconds. Apply those numbers to your walk path in the way shown previously and you’re done. This method may not be scientifically accurate but it’s pretty close and as a result your animation movement and speed will look believable to the viewer.

Output Options

For the first option, you could set up the normal animation, go to Render Frames, and then pick the AR3 preview buttons. This allows you to scroll through all frames in a shaded view, then select the 200 consecutive frames that suit your needs best, and render only those frames.

For the second option, you could cut the existing major path where appropriate or create a new one of suitable length - i.e. 100 meters (400/4). Then set a frame count of 200 and render just those 200 frames. As a result of these actions you may finish up in a situation where you need to renumber your frames, or reverse their numbering order, and so on. There is an excellent free utility available for this purpose called ReNum. It is available at http://www.accustudio.com/marketplace/freeware.htm or at http://www.gromada.com/temp/renum130.exe.

There are also many good utilities available for manipulating your AVI files - if you go the AVI route. For example, AVI Frame Rate is a free utility useful to change the frame rate of an assembled AVI. Similarly AVI Edit is a free utility that enables all kind of AVI manipulation and image assembly. Both are available for download at http://www.am-softhome.com. AccuStudio also has an extensive listing of suitable programs - many of which are free. The Radgame BINK tools in particular are excellent.

The Internet is a great source of information about the speed of many things. Just do a general search with a good search engine.

Combining Clips

Try this experiment. Next time you’re watching television turn off the sound completely. This enables you to focus just on the visuals. Now look at what’s happening. A few seconds of footage looking this way, then a few seconds of footage looking that way, then a few seconds looking back again from the first viewpoint, then maybe a long shot or two, then maybe a zoom shot, and so on.

You can achieve all this with a bit of planning and by combining different AR3 animation clips. Any scene can have as many paths through it as you wish. You might color code your paths to avoid confusion, then sweep your camera through the scene any which-way you want, as many times as you need. Your rendered clips can then be assembled in whatever order makes a good storyline and has an interesting and logical flow to it. Try now to think like a Hollywood director and not like an animator - the audience doesn’t care about technical details - they want to be entertained by what they’re seeing, and they want to understand what they’re seeing without having to work hard. Remember, they don’t have the investment in the movie that you do. It’s up to you to get your audience involved and to make them want to see what’s coming up next.

There are many free sound files available on the ‘net, so think about adding a simple soundtrack to your animation. If you think this isn’t important, go back again and try watching several minutes of television without any sound - it sucks.

Reversing Paths

If you find the way you have drawn your spline path(s) creates motion going in the opposite direction to what you want, use the SPLINE/ REVERSE command to reverse the start and end points of the spline. Movement will then go in the opposite direction. If you perform a LIST on the spline you will see the order of control points is now reversed from before.

Some Simple Tricks

SPEED CHANGES

As mentioned before, AR3 has no acceleration or deceleration ability but you can simulate (fake) it pretty well by combining clips of different speeds. Think back to the part about how AR3 divides the major path by the number of frames you have set to calculate the movement from frame to frame. If you lengthen the path and keep the same frame count, or maintain the path while having a lower frame count, AR3 must move further each frame to cover the whole path within the allotted number of frames. The reverse operations create the opposite effect and AR3 moves less each frame. The overall effect is of the camera moving either slower or faster along the path, depending on your needs. When you combine multiple clips together you can create the illusion of gradual or rapid speed changes, and so on.

ZOOM LENS

The option to change lens length during the course of a clip can be used to create a zoom lens effect. This is done by setting different starting and ending lenses. The starting lens is selected by picking EDIT ANIMATION/ MORE SETTINGS/ CAMERA. The ending lens is selected by going to EDIT ANIMATION and then picking on the path segment name. This will make the EDIT tag available. Pick that and the ENDING LENS LENGTH box will now be available to set the ending lens value. Remember that wide-angle lenses have a small lens setting and zoom lenses have a larger lens setting.

Click on the following link for a brief demo of this effect: LINEAR.EXE

SPIRAL PATH

Refer to Image 1 below. Here spiral.lsp has been used to create a spiral camera path.

The camera follows the spiral path up and away from the mannequin. Click the following link for a brief demo: SPIRAL.EXE

If you were to reverse the spline (see above) then the camera would spiral down towards the mannequin.

Other paths can be made in a similar way. A spiral path could be used to make an airplane appear to perform barrel rolls for example. A little imagination is all it takes.

This completes the tutorial.

rev 2.17.02   ::   For more information visit www.accustudio.com