I need to determine a set of points which lie on a surface (x,y,z coordinates for each point in the u and v directions) when given a knot
vector, control points and weights in NURBS format. I know that there are NURBS evaluators in openGL (glEvalCoord), similar to using a vertex, but I do not know how to obtain the actual coordinates for each point that it has generated from the evaluator (for each u and/or v input). Any help that you could provide would be helpful. Thank you.
Look up "glFeedbackBuffer".
Knackered
That's not a NURBS evaluator. If you want NURBS, look into glu.Originally posted by Student_1138:
I know that there are NURBS evaluators in openGL (glEvalCoord)
Or look for a 3rd party library. I think there was one called NURBS++ and it will let you have the tesselated geometry.
A quick search gives
http://libnurbs.sourceforge.net/
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Sig: http://glhlib.sourceforge.net
an open source GLU replacement library. Much more modern than GLU.
float matrix[16], inverse_matrix[16];
glhLoadIdentityf2(matrix);
glhTranslatef2(matrix, 0.0, 0.0, 5.0);
glhRotateAboutXf2(matrix, angleInRadians);
glhScalef2(matrix, 1.0, 1.0, -1.0);
glhQuickInvertMatrixf2(matrix, inverse_matrix);
glUniformMatrix4fv(uniformLocation1, 1, FALSE, matrix);
glUniformMatrix4fv(uniformLocation2, 1, FALSE, inverse_matrix);
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