background

Syntax:

background (backdrop = <filename>);

or

background (color = (r, g, b));

or

background (color = <texture>);

Default:

none

Purpose:

The file filename could be a digitized image, a previously rendered screen, or a painted image. It must be of the same size and resolution as the image being ren-dered. This statement is animatable.

The background can be procedurally modeled, or it can be textured with a file. For details of procedures, please see Procedural Textures and Natural Phenomena.

If a file texture is used, it will be stretched to match the image dimensions. Both RGB (24 bit) and scalar (8 bit) files can be used. Note that if you use an 8-bit file for the background, you will get a grey scale background.

This allows reflected environments to also be used for background.

NoteThe only type of backgrounds that will reflect or refract properly in the Alias Raytracer are environment maps. Color procedural backgrounds will show up on reflective objects and will show through transparent objects, but the results may look incorrect. Ramp and file backgrounds will not appear at all in reflections or refractions. Otherwise, the background will look and act the same as in the Alias RayCaster when no objects are obscuring the background.

Environment map backgrounds are useful in the Alias RayTracer. They allow an object to reflect parts of itself by using the Raytracer, while saving rendering time by creating the reflections of surrounding objects with a cubic reflection map in the shader.