Hi, As you can see in images (img1 img2 img3), there is some kind of diffusion or smth when one side of object covers another side, is there a way to avoid this? my light setup is as folloows: GLfloat materialDiffuse[] = { 1.0, 1.0, 1.0, 1.0 }; GLfloat materialSpecular[] = { 1.0 ,1.0, 1.0, 1.0 }; GLfloat materialAmbient[] = { 0.2 ,0.2, 0.2, 1.0 }; GLfloat materialEmission[] = { 1.0 ,1.0, 1.0, 1.0 }; GLfloat materialShininess[] = { 100 }; GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 }; // setup material settings glMaterialfv( GL_FRONT, GL_DIFFUSE, materialDiffuse ); glMaterialfv( GL_FRONT, GL_SPECULAR, materialSpecular ); glMaterialfv( GL_FRONT, GL_SHININESS, materialShininess ); glMaterialfv( GL_FRONT, GL_AMBIENT, materialAmbient ); glMaterialfv( GL_FRONT, GL_EMISSION, materialEmission ); glLightfv(GL_LIGHT0, GL_POSITION, light_position); // enable lighting glEnable( GL_LIGHTING ); glEnable( GL_LIGHT0 ); glDepthFunc( GL_LEQUAL ); glEnable( GL_DEPTH_TEST ); glEnable( GL_AUTO_NORMAL ); glEnable( GL_NORMALIZE ); glColorMaterial ( GL_FRONT_AND_BACK, GL_EMISSION ) ; glEnable ( GL_COLOR_MATERIAL ) ;

The pictures look like a classical case of Z-fighting. To correct this you might try to adjust the z-near and z-far values for the clipping planes or you can use glPolygonOffset.
Here's some more information: http://www.opengl.org/resources/faq/technical/depthbuffer.htm

Also, unless you're rendering maps using glEvalCoord, the glEnable(GL_AUTO_NORMAL) will do nothing.

Quote:http://developer.3dlabs.com/documents/GLmanpages/glevalcoord.htm
If automatic normal generation is disabled, the corresponding normal map GL_MAP2_NORMAL, if enabled, is used to produce a normal. If neither automatic normal generation nor a normal map is enabled, no normal is generated for glEvalCoord2 commands.

You were right. My zNear was set to 0, I set it to 1 and it looks fine now, thanks.