z matrix value opengl

Graphics and GPU Programming Programming OpenGL

Started by quadelirus June 23, 2008 04:21 PM

1 comment, last by idinev 15 years, 9 months ago

quadelirus

122

Author

June 23, 2008 04:21 PM

Is there an easy way to determine the current z-depth after applying glTransform & glRotate several times?

Buckeye

10,754

June 23, 2008 04:30 PM

Can you ask your question in another way? Is your question about the z-buffer, or the z coordinate of an object, or.. ?

Please don't PM me with questions. Post them in the forums for everyone's benefit, and I can embarrass myself publicly.

You don't forget how to play when you grow old; you grow old when you forget how to play.

idinev

236

June 23, 2008 04:43 PM

Maybe like this:

Mat4 glGetMatrixMVP(){	Mat4 mv,p;	glGetFloatv(GL_PROJECTION_MATRIX,p.mat_array);	glGetFloatv(GL_MODELVIEW_MATRIX,mv.mat_array);	Mat4 mvp = p*mv;	return mvp;}...Mat4 mvp = glGetMatrixMVP();vec4 origin=vec3(0,0,0,1);vec4 transformed = mvp * origin;now you have the transformed.z value