source files: xvol.[ch]
(XVOL-BUILD-RENDERING-RELATION [ :RANGE '( :MIN <fix:min> :MAX <fix:max> :MATERIAL <material> ) ] [ :RESULT-IN <grl:rendering-relation> ] )
Any number of the indicated :RANGE lists may be supplied.
Each list specifies the material properties for voxels
values in the range [min,max). The
max value for
each list must be less than (or equal to) the
value of the next.
Material properties for voxel values between the given ranges are linearly interpolated. It is a good idea to leave a gap of this sort; This provides something of the effect of anti-aliasing in voxels with intermediate values (which may in fact contain a mixture of the two substances).
If a :RESULT-IN value is supplied, and is of appropriate type See section XVOL-RENDER-IN-COLOR. the result will be placed in it and 'image' returned; otherwise, a fresh relation will be allocated and returned.