Roping artifacts on highlights

The hard-edged highlights that the standard Phong model produces (many times magnified by a noisy bump map).

See Shading model in Render > Multi-lister and Post Filter in Render > Globals.

Use the Blinn shading model instead. Also try turning the Post Filter option ON in the Blur Effects section of the Render Globals window.

Objects and raytracing

Problem: Transparent objects do not show the background when raytracing, or Reflective objects do not reflect the background when raytracing

You may be using a 2D texture or image plane on the background. For raytraced images, you must use either a flat color or an environment map for the background for reflected/refracted rays to render correctly.

Use a Spherical or Ball environment with your texture or image applied to it.

Thin highlights have roping artifacts

This may be due to the hard-edged highlights that the standard Phong model produces (many times magnified by a noisy bump map).

Do one of the following:

See Shading model in Render > Multi-lister.

• Use the Blinn shading model.

  See Post Filter in Render > Globals.

• Set Post FilterON in Render Globals.

Blended surfaces do not render

If part of a blended surface is visible, and another part is invisible, the surface will not render. The invisible part of the surface is not written to the SDL file, so the blend cannot be regenerated for each frame.

Make all parts of a blended surface visible.

Displacement mapping

Problem: Displacement mapping does not work for layered shaders.

Only the lowest available layered shader can apply a displacement map.

Create a single displacement map and apply it to the lowest layered shader.

BOT (block oriented texture) files

Problem: Renderer does not recognize BOT (block oriented texture) files directly applied as texture maps.

See Texture Caching in Render > Globals.

Set Texture CachingON under Render Globals.

Invisible instances of objects are visible

This is a known limitation.

Duplicate the object instead of instancing it.

Bump map using a file texture

Problem: Bump map using a file texture does not render as expected.

If the file has an alpha channel, then the alpha channel is used for bump mapping. If the file does not have an alpha channel, the RGB color channels are converted into a grayscale using a luminance calculation, and then used for bump mapping.

Remove the alpha channel from the file texture.

Banding appears on low intensity objects

This is due to the 8-bit per color channel limitation.

Do one of the following:

• Set Film Grain to 0.01 in the environment shader.
• Alter the colors of the lights by random, fractional amounts from pure integer values. For example, change (255,255,255) to (254.3,255.2,254.9).

Templated objects

Problem: Templated objects rendered in an animated sequence become visible.

This is a known limitation.

Depth of field produces aliasing

With depth of field, the edge of an object in focus against a very blurry foreground or background sometimes shows aliasing.

Render foreground blurry elements separately and composite them.