source files: xvol.[ch]
(XVOL-RENDER :VOXELS <grl:voxels> [ :SLICE <fix:slice> ] [ :DEPTH <fix:depth> ] [ :AXIS <fix:axis> ] [ :MIN <fix:min> ] [ :MAX <fix:max> ] [ :ZOOM-BY <fix:zoom> ] [ :RESULT-IN <grl:image> ] )
This function is intended to generate useful volume
renderings as quickly as practical: It does no per-voxel
computations slower than an integer add or table lookup, and
generates a monochrome result shaded by depth, with all
voxels either completely opaque or completely transparent,
'voxels' should be either a rank-three CLASS-16-BIT-FLOAT-ARRAY or else a graphic relation holding such an array, named :INTENSITY.
'slice' indicates the first visible plane along the axis: planes numbered less than this are completely ignored during rendering.
'depth' controls the number of visible planes: Shading runs from full white at 'slice' to full black as 'slice'+'depth'.
'Axis' indicates which direction the view should be taken. It should be 0, 1 or 2, and defaults to 0.
'zoom' indicates how much the image should be enlarged by during the copy, and defaults to 1. Currently, the only other supported values are 2, 4, 8 and 16.
'min', 'max' and the return value are as in XMRI-READ-RGB-IMAGE. See section XMRI-READ-RGB-IMAGE.
If a :RESULT-IN value is supplied, and is of appropriate type, the result will be placed in it and 'image' returned; otherwise, a fresh image relation will be allocated and returned.