The RenderMan Interface - Paul Bourke

If the Detail capability is not supported by a particular implementation, all object representations
which include RI INFINITY in their detail ranges are rendered.
4.2.12 Geometric approximation
Geometric primitives are typically approximated by using small surface elements or polygons.
The size of these surface elements affects the accuracy of the geometry since large
surface elements may introduce straight edges at the silhouettes of curved surfaces or cause
particular points on a surface to be projected to the wrong point in the final image.
RiGeometricApproximation ( RtToken type, RtFloat value )
The predefined geometric approximation is ”flatness”. Flatness is expressed as a distance
from the true surface to the approximated surface in pixels. Flatness is sometimes
called chordal deviation.
RIB BINDING
GeometricApproximation ”flatness” value
GeometricApproximation type value
EXAMPLE
GeometricApproximation ”flatness” 2.5
SEE ALSO
RiShadingRate
4.2.13 Orientation and sides
The handedness of a coordinate system is referred to as its orientation. The initial ”camera”
coordinate system is left-handed: x points right, y point up, and z points in. Transformations,
however, can flip the orientation of the current coordinate system. An example
of a transformation that does not preserve orientation is a reflection. (More generally, a
transformation does not preserve orientation if its determinant is negative.)
Similarly, geometric primitives have an orientation, which determines whether their surface
normals are defined using a right-handed or left-handed rule in their object coordinate
system. Defining the orientation of a primitive to be opposite that of the object coordinate
system causes it to be turned inside-out. If a primitive is inside-out, its normal will be computed
so that it points in the opposite direction. This has implications for culling, shading,
and solids (see the section on Solids and Spatial Set Operations). The outside surface of a
primitive is the side from which the normal points outward; the inside surface is the opposite
side. The interior of a solid is the volume that is adjacent to the inside surface and
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