[Plib-devel] Quaternion Usage Question

[Negative0 <neg...@ea...>]

I have seen demos of Quaternions where rotation by an axis uses a more
logical view point axis than the actual objects axis for rotation. I can't
find any guides on how to use the simple geometry quaternion routines so I
have tried the following:

sgMakeIdentQuat( &Q );
sgRotQuat( &Q, 90.0, 1.0, 0.0, 0.0 );

At this point I have tried using:
sgMakeRotMat4( rotation, &Q );
sgXformVec3( point, rotation )

and:
sgMakeRotMat4( rotation, &Q );
glMultMatrixf( rotation )

as well as:
sgQuatToAngleAxis(...)
glRotatef(...)

These don't produce any meaningful output. One combination I made actually
rotated the 90 along the X axis, but drifted 30 degrees along the Z axis as
well. I would greatly appreciate any examples, pointers, or descriptions on
how to properly setup, rotate, and use the quaternion transformations.


Thanks in advance,

-negative0