Drawing "Overlay" problem...

OpenGL Development JOGL Development
#1

Hi guys!

Question from total noob… :slight_smile:

If I want to make sure that I will draw a shape over the staff which is already drawn is it enough to clear the Depth Buffer before I draw that shape?
It works for me fine that way provided that I didn’t draw any transparent shapes before (especially transparent & having depth test / depth buffer off). But if I do draw transparent shapes and played with the depth buffer before, than even if I clear depth buffer before I draw the shape, the one I want to be in front, some transparent shapes which I draw before will pop up in front… Why? ???

Thanks in advance…

Bohdan.

Edit: actually, I a bit wrong… not that transparent will pop up in front, but that shape I draw the last, will be drawn like it actually went through depth test (though the depth buffer should be clear at this stage already)… ???

#2

Anybody, any hints? Please…
Just driving me mad…, can’t understand why clearing depth buffer is not always enough ???

#3

Problem is resolved ;D. Wrong set depth mask was the answer ;D

Cheers,
Bohdan.

#4

Can you post your code or what depth mask and did you use to draw this?

#5

Basically, the problem was that somewhere in the drawing procedure, before I draw “overlay” shape, I had writing to depth buffer disabled, consiquently “overlay” shape never appeared in depth buffer (and I thought it was), so when transparencies where drawn next, they just was not checked (depth test) against this shape and went over it… that’s it… I just by mistake left writing to depth buffer off, and forget about that and couldn’t spot it for a while :o .