tabor25

07-05-2007, 03:32 AM

Hello,

i draw a sphere in wireframe mode with face culling on. I also want to draw the vertices of the wireframe by using glVertex3fv. I cannot use the extension GL_EXT_cull_vertex for vertex culling. Because i have the normal for each vertex, it must be possible to decide wich vertex has to be drawn and wich not. Can i accomplish this task by using a vertex shader? If yes, is it possible to prevent drawing the vertex after it reached the vertex shader executing the culling test. If i can't use a vertex shader, how do i get the eye vector in object space to do the scalar product with the vertex normal?

i draw a sphere in wireframe mode with face culling on. I also want to draw the vertices of the wireframe by using glVertex3fv. I cannot use the extension GL_EXT_cull_vertex for vertex culling. Because i have the normal for each vertex, it must be possible to decide wich vertex has to be drawn and wich not. Can i accomplish this task by using a vertex shader? If yes, is it possible to prevent drawing the vertex after it reached the vertex shader executing the culling test. If i can't use a vertex shader, how do i get the eye vector in object space to do the scalar product with the vertex normal?