The RenderMan Interface - Paul Bourke

SEE ALSO
RiExterior RiAtmosphere
RiExterior ( RtToken shadername, ...parameterlist...);
This procedure sets the current exterior volume shader. shadername is the name of a
volume or atmosphere shader. If shadername is RI NULL, the surface will not have
an exterior shader.
RIB BINDING
Exterior shadername ...parameterlist...
EXAMPLE
RiExterior ( ”fog,” RI NULL);
SEE ALSO
RiInterior, RiAtmosphere
If a particular implementation does not support the Volume Shading or Ray Tracing capabilities,
RiInterior and RiExterior are ignored; however, RiAtmosphere will be available in
all implementations.
4.2.7 Shading rate
The number of shading calculations per primitive is controlled by the current shading rate.
The shading rate is expressed in pixel area. If geometric primitives are being broken down
into polygons and each polygon is shaded once, the shading rate is interpreted as the maximum
size of a polygon in pixels. A rendering program will shade at least at this rate,
although it may shade more often. Whatever the value of the shading rate, at least one
shading calculation is done per primitive.
RiShadingRate ( RtFloat size )
Set the current shading rate to size. The current shading rate is specified as an area in
pixels. A shading rate of RI INFINITY specifies that shading need only be done once
per primitive. A shading rate of 1 specifies that shading is done at least once per
pixel. This second case is often referred to as Phong shading.
RIB BINDING
ShadingRate size
EXAMPLE
RiShadingRate (1.0);
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