Perspective view is a mess up with depth testing.... ????

OpenGL OpenGL: Basic Coding
1

Hi all!! I have a 3d scene, and when I apply an orthographic projection, depth testing occurs well, but when I apply a perspective projection, by example the triangle becomes invisible!!!
Detail: I apply camera viewing transforms, but I’m remodeling it to simple rotation/translation transforms (it is modelled only with gluLookAt)… Could you please answer me this question, and in case of a mess up, (need to do with ortographic), do I need to do the near/far motion by glScale?? Thanks in advance!!

2

How did you apply perspective projection? It is more likely that you use wrong projection than you problem is depth buffer related.

3

hi! I apply perspective projection by a call to
gluPerspective(90, 1, -100, 100); By the way… Thanks!!

4

Of course this doesn’t work. The zNear parameter in gluPerspective must be greater than zero.
Try this
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(90.0, 1.0, 1.0, 201.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0f, 0.0f, -101.0f); // Puts the origin into (zFar + zNear)/2.0