Accurender FAQ

1.  What is non-photometric raytracing ?

2.  How do I render in Architectural Desktop 3 or 3.3

3.  Matrox video and Accurender

4.  How do I render in Architectural Desktop 2

5.  How do I render in Architectural Desktop 1

6.  Elsa Synergy video and Accurender

7.  Does Accurender run in AutoCAD 2000

8.  How do I preview trees ?

9.  Why are the renderings too dark or too light ?

10.  Ati video and Accurender

11.  transparent materials rendering black.txt

12.  Why is my model taking so long to translate ?

13.  How can I make the sun shadows lighter ?

14.  How do I get more than one sun ?

15.  What is the Highlight Property ?

16.  What is Clear Finish ?

17.  What is Angular Blend and Clear Finish ?

1.  What is non-photometric raytracing ?
AccuRender 3 introduced photometric rendering. Photometric render mode works well for architectural scenes. It captures subtle differences in light and can render realistic scenes over a broad range of lighting conditions. Interior and exterior architectural scenes work well in this mode since there tends to be a broad range of lighting effects in an image. With photometric rendering lights are specified and calculated using real-world units such as watts, and exposure adjustment after the image is created is possible. Photometric raytracing is also required for radiosity calculation.

Non-Photometric Render Mode
Non-photometric raytracing mode tends to work well for studio light scenes like product shots, automobiles, booth structures, and other freestanding objects. These scenes normally have a smaller range of lighting affects and unrealistic lighting effects are often desired to accentuate parts of the objects. This rendering method also may work best when rendering a simple scene that does not need to look realistic.

In non-photometric mode, light values are specified and calculated using arbitrary numbers rather than real-world methods, and exposure adjustment after creating the image is not available. Some AccuRender dialog boxes will look different in this mode. This mainly affects lighting values.

Setting the Render Mode
By default, AccuRender renders in photometric mode.

To switch AccuRender into non-photometric mode:
Open and close the AccuRender control panel to make sure AccuRender is loaded.
At the AutoCAD Command prompt, type (ar3_method 2).
The render mode setting is saved with the drawing. Other drawings and new drawings will render in the photometric mode.

To switch AccuRender back to the photometric mode, type:
Open and close the AccuRender control panel to make sure AccuRender is loaded.
At the AutoCAD Command prompt, type (ar3_method 0).

2.  How do I render in Architectural Desktop 3 or 3.3 objects ?

Generally, you will assign materials to objects in Architectural Desktop. Unfortunately, there are objects in Architectural Desktop like windows and stairs that have sub-objects. You must assign materials to sub-objects by color if you want them to render with different materials.
You will need AccuRender 3.1 build 253 or later.

Configuring Architectural Desktop 3 for Rendering

There are slightly different settings for Architectural Desktop 1, 2 and Architectural Desktop 3. If you are using Architectural Desktop 1 or 2, see FAQ specifically for the ADT version you have. This document covers both Architectural Desktop 3 and 3.3.

To configure Architectural Desktop 3 for rendering:

  1. Select the layout and the viewport with the model view to render.

  2. Make the viewport active by double clicking it.

  3. To create a new configuration, from the Desktop menu, click Display Manager.

  4. In the Display Manager dialog box, right-click the Configuration folder, and select New from the cursor menu.

  5. In the left pane of the Display Manager dialog box, type a name for the configuration, such as AccuRender, and press Enter.

  6. In the right pane of the Display Manger dialog box, on the Configuration tab, check the Override View Direction box.

    The Fixed Display Configuration frame, will now read “Viewport View Direction.”

  7. In the right pane of the Display Manger dialog box, on the Configuration tab the View Direction will read “Default”, and the Display Representation Set will be set to “MODEL.”

  8. To set the current display configuration, in the left pane of the Display Manger dialog box, right-click AccuRender, and select Set to Current Viewport.

  9. In the Display Manager dialog box, click OK.

    Now when the AccuRender configuration is current, the sub-objects in Architectural Desktop will render properly. You can switch between this configuration and the other configurations from the Display Manager dialog box.

Assigning Materials to Architectural Desktop 3 Objects with Subcomponents

Architectural Desktop objects are made up of a number of sub-objects. For instance the Window, which is an object in Architectural Desktop, is made of three sub-objects (Glazing, Frame, and Sash.)  If you would like everything in an object to be one material, you can assign the material to the object's layer. However, if you would like to assign materials to the sub-objects, you must make each sub-object a different color.  The typical styles to edit are Walls, Windows, Doors, Roofs.  They would follow the same procedure as detailed below for Doors.

To change the color of sub-objects in Architectural Desktop 3 Doors:

  1. From the Design menu, click Doors, and then click Door Styles.

  2. In the Door Styles dialog box, from the Name column, right-click the style door object you would like to change or Standard, and select Edit from the cursor menu.

  3. In the Door Style Properties dialog, on the Display Props tab, under the Property Source, select System Default and click the Edit Display Props button.

  4. In the Entity Properties dialog box, on the Layer/Color/Linetype tab, from the Component list, click the color for the component you want to change.

  5. In the Select Color dialog box, select a color, and click OK.

    The number of the color will be used to reference the material.

  6. Click OK in all the dialog boxes.

  7. From the Design menu, set colors for the other components.

  8. At the Command prompt, type regen.

    The objects will now be displayed in their new color.

Assign AccuRender Materials for Architectual Desktop 3

You must now assign AccuRender materials to the colors of the sub-objects.

To assign materials to the colors:

  1. Start AccuRender.

  2. In the AccuRender dialog box, click on the Setup tab, click Materials.

  3. In the Assign Materials dialog box, in the assignment type list in the upper left, select By ACI (AutoCAD Color Index).

  4. Under ACI, select a color number, and click Assign Material.

  5. In the Material Library dialog box, select the material.


3.  Matrox video and Accurender
General instability in AccuRender can be caused by poor OpenGL drivers.
The problem I could identify is the dual head display. (I am using
the 5.30.007 driver.) To fix, go to the Matrox display
property setting, and click in advanced dialog box. You should be able
to get in to the control over Dualhead Tab. Click to turn the dual head on.
(Enable the last option.) After you reboot the system, go
to the display property and setting tab again. Now you will see the picture
of two monitors labeled no.1 and no.2 one with color. You then should
double-click the one that is in black and white. You will be notified that this
monitor will be part of your desktop. Click yes. That's all there is to
it. Everything should run fine for AccuRender 3.

You can now use AccuRender 3 with G400 Dual heads with no problem, freeze,
or system hang when loading the model or orbitting. Hope this will
be helpful for many users.


4.  How do I render in Architectural Desktop 2
Generally, you can assign materials to objects in Architectural Desktop. Unfortunately, there are objects in Architectural Desktop like windows and stairs that have sub-objects. You must assign materials to sub-objects by color if you want them to render with different materials.

You will need AccuRender 3 build 202 or later.
Configuring Architectural Desktop 2 for Rendering
There are slightly different settings for Architectural Desktop and Architectural Desktop 2. If you are using Architectural Desktop 1, see the previous section.
To configure Architectural Desktop 2 for rendering:
From the Desktop menu, click Display System, and then click Display Configurations.
To create a new configuration, in the Display Configurations dialog box, click New.
In the Name dialog box, enter a name for the new configuration such as RENDER, and click OK.
In the Display Configurations dialog box, from the Name list, select RENDER, and click Edit.
In the Display Configurations dialog box, on the Configuration tab, clear the Configuration is View Direction Dependent checkbox in the middle of the dialog.
Then at the top of the dialog under Fixed Display Configuration frame, in the Display Representation Set list, select Model, and click OK.
In the Display Configurations dialog box, click OK.
Now when the RENDER configuration is current, the sub-objects in Architectural Desktop will render properly. You can switch between this configuration and the standard configuration on the fly.
To set the display configuration:
From the Desktop menu, click Select Display.
In the Viewport Display Configuration dialog box, under System Default Display Configuration, in the Name list, select RENDER, and click OK.
Assigning Materials to Architectural Desktop 2 Objects with Subcomponents
Architectural Desktop objects are made up of a number of sub-objects. For instance Window, which is an object in Architectural Desktop, is made of three sub-objects (Glazing, Frame and Sash.) If you would like everything in an object to be one material, you can assign the material to the object's layer. However, if you would like to assign materials to the sub-objects, you must make each sub-object a different color.
To change the color of sub-objects in Architectural Desktop 2 Doors:
From the Design menu, click Doors, and then click Door Styles&ldots;
In the Door Styles dialog box, from the Name column, select the style door object you would like to change or use Standard.
After highlighting the door style you want to change, pick the Edit button.
In the Door Style Properties dialog, pick on the Display Props tab.
From the Display Props tab, under the Property Source column select System Default and pick the Edit Display Props button.
In the Entity Properties dialog box, on the Layer/Color/Linetype tab, from the Component list, click the color for the component you want to change.
In the Select Color dialog box, select a color, and click OK. The number of the color will be used to reference the material.
Pick OK from Entity Properties, pick OK from Door Style Object, and pick OK from Door Styles.
From the Design menu, set colors for the other components.
At the Command prompt, type regen.
The objects will now be displayed in their new color.
Assign AccuRender Materials for Architectual Desktop 2
You must now assign AccuRender materials to the colors of the sub-objects.
To assign materials to the colors:
Start AccuRender.
In the AccuRender dialog box, click on the Setup tab, click Materials.
In the Assign Materials dialog box, in the assignment type list in the upper left, select By ACI (AutoCAD Color Index).
Under ACI, select a color number, and click Assign Material.
In the Material Library dialog box, select the material.


5.  How do I render in Architectural Desktop 1
Generally, you can assign materials to objects in Architectural Desktop. Unfortunately, there are objects in Architectural Desktop like windows and stairs that have sub-objects. You must assign materials to sub-objects by color if you want them to render with different materials.

You will need AccuRender 3 build 202 or later.
Configuring Architectural Desktop 1 for Rendering
Here are the specific steps to configure Architectural Desktop 1 for rendering. If you are using Architectural Desktop 2, please go to the next section.
From the Desktop menu, click Display Control, and then click Edit Display Configuration.
To create a new configuration, in the Display Configurations dialog box, click New.
In the Name dialog box, enter a name for the new configuration such as RENDER, and click OK.
In the Display Configurations dialog box, from the Name list, select RENDER, and click Edit.
In the Display Configurations dialog box, on the Configuration tab, clear the Configuration is View Direction Dependent checkbox, and under Fixed Display Configuration, in the Display Representation Set list, select Model, and click OK.
In the Display Configurations dialog box, click OK.
Now when the RENDER configuration is current, the models in Architectural Desktop will render properly. You can switch between this configuration and the standard configuration on the fly.
To set the display configuration:
From the Desktop menu, click Display Control, and then click Default Display Configuration.
In the Viewport Display Configuration dialog box, under System Default Display Configuration, in the Name list, select RENDER, and click OK.
To set the display configuration:
From the Desktop menu, click Select Display.
In the Viewport Display Configuration dialog box, under System Default Display Configuration, in the Name list, select RENDER, and click OK.
Assigning Materials to Architectural Desktop 1 Objects
Architectural desktop objects are made up of a number of sub-objects. For instance a Window, which is an object in Desktop is made of three sub-objects (Glazing, Frame and Sash.) If you would like everything in an object to be one material, you can assign the material to the object's layer. However, if you would like to assign materials to the sub-objects, you must make each sub-object a different color.
To change the color of sub-objects in Architectural Desktop:
From the Desktop menu, click Display Control, and then click Default Representations.
In the Display Representation Defaults dialog box, from the Object Type list, select an object you would like to change.
In the Display Representations list, select Model.
Click Edit.
In the Entity Properties dialog box, in the Component list, click the color for the component you want to change.
In the Select Color dialog box, select a color, and click OK. The number of the color will be used to reference the material.
In the Display Representation Defaults dialog box, set colors for the other components, and click OK.
At the Command prompt, type regen.
The objects will now be displayed in their new color.
Assign AccuRender Materials for Architectual Desktop 1
You must now assign AccuRender materials to the colors of the sub-objects.
To assign materials to the colors:
Start AccuRender.
In the AccuRender dialog box, click on the Setup tab, click Materials.
In the Assign Materials dialog box, in the assignment type list in the upper left, select By ACI (AutoCAD Color Index).
Under ACI, select a color number, and click Assign Material.
In the Material Library dialog box, select the material.


6.  Elsa Synergy video and Accurender
General instability in AccuRender can be caused by poor OpenGL drivers.

AccuRender 3 does not run well on the standard drivers of the ELSA synergy II cards.
I was able to fix the problems with the addition of some Elsa files that they have on their web site.
The drivers on the web site were updated on 10-28-99, so they are very new.

I downloaded and installed the files -

syiibios.zip - This allows you to flash your video bios to 3.05.00
syiint4b.zip - This installs the Elsa Driver 4.11.10.150
powerl_b.zip - This installs the Powerlib drivers to 6.00.03.03

You can look in your display properties dialog under the information tab to check these numbers against the drivers that you have.
I have done more testing and I am finding that there is also a conflict with AccuRender and the Elsa EV3D (ElsaView 3d 2) add-on.
If you uninstall the ELSAview 3d 2 out of Control Panel -> add remove programs, you will find more stability.
This has fixed all the problems I can find with this card.


7.  Does Accurender run in AutoCAD 2000
Yes, AccuRender 3.1 will run in AutoCAD 2000.
AccuRender 3.0 users can download a free update off the web.


8.  How do I preview trees ?
In AccuRender 2 the tree preview used bitmaps as previews for the trees and their colors. AccuRender 3 previews a wireframe of the tree in the library. A bitmap previewer will be added into AccuRender 3 later this year. That will be available on the Web as a free upgrade.


9.  Why are the renderings too dark or too light ?
In some cases, materials in the rendering may look much lighter or much darker than you expect, even though they look fine in the material library. One common reaction to this is to turn up the brightness of all the lights in the model. This strategy is not effective due to AccuRender 3's automatic exposure adjustment. Identifying the real cause of the problem is the first step in solving it.

One of the most common causes of materials looking too light or too dark is that AccuRender has over or underexposed the image. When overexposed, the image will look very white and burned out. This happens most often on images in which all the objects in the model are very reflective. If this is the case set the exposure brightness to a lower value (Raytrace tab, Adjust Exposure. As a starting point, set Brightness to -0.5). If all the materials are very dark and gray, try setting the Brightness to 0.375. If these settings improve the image, experiment with the Brightness setting until you get what you want.

If you looking outside from an interior, the exterior objects look very light. This is because the light outside is many times brighter than the light inside. This is very similar to the problems that you have with a camera when taking a similar shot. There is a discussion on page 99 of the AccuRender 3 manual on techniques to deal with this problem.


10.  Ati video and Accurender
General instability in AccuRender can be caused by poor OpenGL drivers.

We have identified a problem with the released versions of the ATI 128 video
cards. This includes the Rage and the Rage Pro cards. It seems that if you
try to render to Walkabout, AutoCAD will blow up. This is a problem with
their video driver. A new version of their driver will fix the problem. It
is available at:
http://www.atitech.com/na/pages/spdrivers/index.html
If you are currently running an ATI card and having problems, please
download this driver. Here are the technical numbers on the new drivers.

RAGE128 Windows 95b/98 Display Driver
Optimized Direct3D/OpenGL Special Purpose Driver
(K6/K7 3DNow!, Pentium III SSE, Quake3 Test)
Version: 6.30CDH34
posted October 27, 1999

RAGE128 Windows NT 4.0 Display Driver
Optimized OpenGL Special Purpose Driver
(K6/K7 3DNow!, Pentium III SSE, Quake3 Test)
Version: 6.30CDH34-4.3.72

11.  transparent materials rendering black.txt
AccuRender sets a limit of three transparent surfaces it can pass through.
After that, it cancels transparency. To set this limit higher,
go to the Raytrace Tab, click on settings, then select the quality
tab. In the tranparency box, click the up arrow to a higher number.
Start with 6.


12.  Why is my model taking so long to translate ?
During AccuRender's model load process, all AutoCAD 3-D objects with curves are approximated by polygon meshes in a process known as tessellation. For 3-D solids, regions, and custom objects, this tessellation is handled entirely by AutoCAD. For extruded circles, extruded arcs, and thick or wide polylines with arcs, AccuRender performs the tessellation. Any translations that take longer than 5 minutes should be considered long.

Common reasons that a model may take a long time to translate are:
The drawing contains many solids.
The drawing contains cylindrical solids (extruded circles).
The drawing contains many plants.

A drawing that is made primarily of solids can be deceptively large at rendering time. A 6 MB model in the AutoCAD can tessellate to 250 MB under certain conditions. The level of tessellation is controlled by the AutoCAD variables VIEWRES and FACETRES. If these are set too high, they over-tessellate the model. VIEWRES is the most sensitive and should always be set to its default of 100. Setting this higher causes an incredible amount of memory to be used with little improvement in quality. FACETRES defaults to a value of 0.5. A setting of 2 is suggested as a starting point. A setting above 8 is considered very high, slows performance, and is usually not required.

Cylindrical solids can also take a lot of time. If you are using cylindrical solids for something like balcony railings on a large building, you can make the railing a square section. This reduces the translation time and the difference is not usually noticable in the final rendering.

Using many plants, large trees, and groundcover can increase translation time. More than 20 trees is considered a lot. Try to use the lowest possible setting of tree possible without sacrificing quality. Also, use groundcover sparingly. You can also use bitmap backgrounds and groundcover to reduce translation times.


13.  How can I make the sun shadows lighter ?
Anytime you think an image is too dark in AccuRender 3, try adjusting the exposure (Raytrace tab, click Adjust Exposure) to set the brightness and contrast and run the raytrace again. If you want an exterior to be lighter, set the Brightness to 0.25 and the Contrast to 0.5 as a starting point. This will lighten the whole image including the shadow areas and the areas in direct sunlight. Experiment with these settings.

If changing the exposure does not give you the image you are looking for, you can also change the sun settings. AccuRender 3 uses a very realistic sun calculation model. Sunlight comprises two elements: direct and indirect sunlight. Indirect sunlight is an estimate of the light reflected from the sky and ground.

By default, the sun has a cloudiness setting of zero, which can create dark shadows. The greater the cloudiness, the less direct sunlight the model will receive, causing lighter shadows. To experiment with increasing the cloudiness (click Lighting, then edit the Sun, Sun and Sky Settings dialog box, Settings tab), set Cloudiness to 0.3 to lighten the shadows.

Another method of reducing the shadow darkness is to change the sun intensity. To experiment with changing the sun intensity (click Lighting, then edit the Sun, Sun and Sky Settings dialog box, Settings tab), set Sun Intensity to 0.4. This will modify the ratio of direct to indirect sunlight. The smaller the sun intensity value, the lighter the shadows will look.

A traditional rendering method to lighten exterior shadows is to insert a second, opposing sun into the model (click Lighting, Add, Parallel). Locate this light source at an opposing angle to the sun's direction. To start with, set the Brightness of the parallel light source to 0.4 and the Shadow Darkness to 0.


14.  How do I get more than one sun ?
To insert a second sun in your rendering click Lighting, Add, Parallel. This is a very similar light source to the distant source in AccuRender 2. You can use parallel light sources to backlight objects. When using this source as a backlight, people often turn the Brightness down to .4 and the Shadow Darkness to 0.

When you add a parallel light source, the location of the insertion point does not affect the direction of the light source; it is only used as a placeholder for the parallel light source. You define the direction by entries in the dialog box.


15.  What is the Highlight Property ?
AccuRender 3.1 includes a new material property: highlight. This property controls the "glossiness" of a material. Use the highlight property for plastics and glossy materials that you do not want to be reflective, but want to have the effect of a glossy finish.

The image below is a red material with highlight turned on. For reference, there is also an image with the red material with highlight turned off. You can see that with highlight turned on, the material looks glossy. This is due to the white reflections of the light sources in the scene. Highlight controls only the reflection of light sources. This should not be confused with the Reflective Finish control on the Main tab of the Material Editor. The Reflective Finish control, as you can see in the third image, also creates a material that reflects light sources, but the material also reflects other objects in the scene and the background, which highlight does not.
To turn on highlight, in the Material Editor, on the Highlight tab, check the Specify Highlight box.
Once the highlight has been turned on, you can control the size, strength, and color of the highlight. The Sharpness control sets the size of the highlight. The control's range is 1 - 301. Lower numbers specify a broader highlight; higher numbers focus the highlight in a smaller area. Values from 1-50 make the most change, 50-300 make little change. The intensity slider adjusts the strength of the highlight. The range is 0-2. This is a multiplier of the strength. For example, 0.5 will only use half the strength of the highlight, while a value of 2 will double the strength of the highlight. You can also change the color of the highlight with the color selector.


16.  What is Clear Finish ?
AccuRender 3.1 includes a new procedural material: ClearFinish™. This procedure blends between two different materials to create special effects. Use ClearFinish to emulate thin, clear finishes on the surface, like car paint and lacquer finishes.

ClearFinish Material

Like angular blend, ClearFinish manages two different materials based on the material’s angle to the view. ClearFinish emulates finishes that are covered with a transparent layer. These materials tend to be a deep color when you look directly at the surface, but as the surface curves away from the view they become highly reflective. Car paints with a clearcoat or clear lacquer finishes are good examples.
To create a ClearFinish procedure, specify a base color and a top coat.
The base material is the main color of the object. Use the color selector to choose the main color of the material.
The top coat is a transparent material that lies on top of the base material. You can adjust the index of refraction (IOR) to control how reflective the top coat is. The higher the IOR, the more reflective the top coat. You can also tint the top coat with a color. This way you can get the material to change the base color as it moves into it reflective state.

17.  What is Angular Blend and Clear Finish ?

Angular Blend and ClearFinish Procedural Materials

AccuRender 3.1 includes two new procedural materials: angular blend and ClearFinish™. Both procedures blend between two different materials to create special effects. Use angular blend to create materials that change characteristics based on the angle of view to the surface of the object. Use ClearFinish to emulate thin, clear finishes on the surface, like car paint and lacquer finishes.

Angular Blend

In the following angular blend example, the material changes color from a light blue to purple. The surface areas that face the viewer are light blue. As the surface starts to curve away from the view, the color blends into purple.

To create an angular blend procedure, specify two materials and start and stop angles.

If the angle of the surface is 0 degrees from the view and the start angle, the first material will show completely. In the area of the surface that is angled between the start angle and the stop angle, there will be a blend of color from the first material to the second material. From the stop angle to 90 degrees from the view, the second material will be the only material showing.

ClearFinish Material

Like angular blend, ClearFinish manages two different materials based on the material’s angle to the view. ClearFinish emulates finishes that are covered with a transparent layer. These materials tend to be a deep color when you look directly at the surface, but as the surface curves away from the view they become highly reflective. Car paints with a clearcoat or clear lacquer finishes are good examples.

To create a ClearFinish procedure, specify a base color and a top coat.

The base material is the main color of the object. Use the color selector to choose the main color of the material.

The top coat is a transparent material that lies on top of the base material. You can adjust the index of refraction (IOR) to control how reflective the top coat is. The higher the IOR, the more reflective the top coat. You can also tint the top coat with a color. This way you can get the material to change the base color as it moves into it reflective state.

 

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