Posted by Wade Walker on May 03, 2012; 12:38am
URL: https://forum.jogamp.org/Problems-with-gluUnProject-tp3954975p3957770.html

Are you sure about this? I looked at the source code for FloatUtil.multMatrixf(), and it seems correct. It takes matrices a and b, which are in column-major order, and multiplies them together, one row at a time from a, against each of the four columns of b. The main loop forms one row at a time of the result matrix d.

Since post-multiplying by a column-major matrix is the same as pre-multiplying by a row-major matrix, perhaps you're just passing your matrices into GLU.gluUnProject() in row-major instead of column-major order?