GL_BLEND quick question

OpenGL OpenGL: Basic Coding
1

Hi just a quick problem I’m having with GL_BLEND and wondering if anybody could help…

I’ve got a background drawn as textured quads, then in the foreground I want to draw some tranparent cubes…

I disable the depth testing and enable glblending, but I can’t get anything to draw in the foreground…

I’ve also added some textured quads to handle text output and THEY display fine, but not my transparent cubes…

any suggestions??

ie…

glDisable(GL_DEPTH_TEST)
glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)

glMatrixMode(GL_MODELVIEW)
glPushMatrix
//draw my cube here
glPopMatrix
glDisable(GL_BLEND)
glEnable(GL_DEPTH_TEST)

thanks for any help…

wazoo

2

Did you try with enabling the depht-test ?

3

instead of glEnable/Disable(GL_DEPTH_TEST)

when doing alpha blended polys use glDepthMask(GL_FALSE);

then with regular polys glDepthMask(GL_TRUE);

4

Yup I tried both the above suggestions already and I still can’t get them to draw…

I’ve even taken out all my lighting code
and played with the view frustrum !!

sigh

does anybody have any other suggestions??

thanks though to everyone who’s helped!

Wazoo