sphrotmatrix(3L)

NAME
     sphrotmatrix - orient spheres

C SPECIFICATION
     #include <gl/sphere.h>

     void sphrotmatrix(mat)
     Matrix mat;

PARAMETERS
     mat    the rotation matrix to specify the orientation of the sphere



DESCRIPTION
     sphrotmatrix specifies the rotation matrix sphdraw uses for displaying
     spheres with a fixed orientation when the sphere attribute, SPH_ORIENT,
     is TRUE.  The orientation of the sphere is applied by the Sphere Library
     before any scaling for radius or translation to the location sent to
     sphdraw.  The matrix provided must be a pure rotation matrix  or the
     results will be unpredictable. When SPH_ORIENT is TRUE, the Sphere
     Library assumes uniform scaling; the effects of nonuniform scaling are
     undefined.

SEE ALSO
     libsphere, sphmode, sphobj, sphdraw, sphgnpolys, sphfree

NOTE
     sphrotmatrix can be used to reduce lighting effects when rotating objects
     that contain spheres.  It can also be used on a VGX, in combination with
     the accumulation buffer, to antialias spheres. For performance, when
     SPH_ORIENT is TRUE, use the SPH_HEMI attribute to draw only the front-
     facing half of the sphere.