The RenderMan Interface - Paul Bourke
The RenderMan Interface - Paul Bourke
The RenderMan Interface - Paul Bourke
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Name Type Description<br />
”blur” varying float Specifies an additional area to be added to the texture area<br />
filtered in both the s and t directions, expressed in units of<br />
texture coordinates. A value of 1.0 would request that the<br />
entire texture file be blurred into the result. A value of<br />
0.001 would request that one extra texture pixel be added<br />
in the case of a one-thousand by one-thousand texture file.<br />
”sblur” varying float Specifies ”blur” individually in the s direction.<br />
”tblur” varying float Specifies ”blur” individually in the t direction.<br />
”width” uniform float This value multiplies the width of the area being filtered<br />
over in both the s and t directions. A value of 0 effectively<br />
turns off texture antialiasing. <strong>The</strong> default value is 1.0.<br />
”swidth” uniform float Specifies ”width” individually in the s direction.<br />
”twidth” uniform float Specifies ”width” individually in the t direction.<br />
”samples” uniform float <strong>The</strong> effective sampling rate when filtering.<br />
”bias” varying float Specifies an additional bias to add to shadow depth<br />
lookups in order to prevent incorrect self-shadowing of<br />
objects.<br />
”filter” uniform string Specifies the name of the filter to use for performing the<br />
percentage-closer filtering over an area of the shadow<br />
map. <strong>The</strong> default is ”box”. Individual implementations<br />
may allow additional filters.<br />
Table 15.2: Shadow Map Access Parameters<br />
Name Type Description<br />
”resolution” uniform float [2] <strong>The</strong> highest resolution of the texture map.<br />
”type” uniform string Returns the type of the texture map file: ”texture”,<br />
”shadow”, or ”environment”.<br />
”channels” uniform float <strong>The</strong> number of channels in the map.<br />
”viewingmatrix” uniform matrix Returns a matrix that transforms points from<br />
”current” space to the ”camera” space from<br />
which the texture was created. (*).<br />
”projectionmatrix” uniform matrix Returns a matrix that transforms points from<br />
”current” space to a 2D coordinate system<br />
where x and y range from -1 to 1. (*)<br />
(*) ”viewingmatrix” and ”projectionmatrix” are only available for shadow maps or other textures<br />
that were created by rendering an image, and assume a common world-space of all<br />
cameras.<br />
Table 15.3: Data names known to the textureinfo function.<br />
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