The RenderMan Interface - Paul Bourke

channels (usually an RGB color) can be accessed using the texture function of the Shading
Language. The texture function requires the name of a texture file containing the texture.
RiMakeTexture ( char *picturename, char *texturename, RtToken swrap, RtToken twrap,
RtFilterFunc filterfunc, RtFloat swidth, RtFloat twidth, ...parameterlist...)
Convert an image in a standard picture file whose name is picturename into a texture
file whose name is texturename. All channels of the picture file will be converted (in
order) to texture channels. The storage format of the texture file and the precision of
stored texture channels are implementation-dependent.
The picture file used as input is not changed or otherwise affected by RiMakeTexture.
RIB BINDING
MakeTexture picturename texturename swrap twrap filter swidth twidth ...parameterlist...
The filter parameter should be one of ”box”, ”triangle”, ”catmull-rom”, ”b-spline”, ”gaussian”
and ”sinc”. These correspond to the predefined filter functions described in
RiPixelFilter.
EXAMPLE
RiMakeTexture(”globe.pic”, ”globe.tx”, ”periodic”, ”clamp”,
RiGaussianFilter, 2.0, 2.0, RI NULL);
SEE ALSO
RiTextureCoordinates, texture() in the Shading Language
7.1.2 Making environment maps
Environment maps are images representing the color of an environment in a particular
direction. An environment map is accessed using a direction vector; this vector is often
the direction of a mirror reflection and hence environment maps are often referred to as
reflection maps. However, any direction can be computed by a user-defined shader. An
environment map image consists of one or more channels. A single channel or a group of
n channels (usually an RGB color) can be accessed using the environment function in the
Shading Language. Environment maps can be input in two formats. The first is as a single
latitude-longitude image. Environment maps in this form are fairly easy to create using a
paint system. The second format is a set of six cube face projections. Environment maps in
this form are naturally created by the rendering program.
RiMakeLatLongEnvironment ( char *picturename, char *texturename,
RtFilterFunc filterfunc, RtFloat swidth, RtFloat twidth, ...parameterlist...)
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