does it matter in which order transparent stuff is drawn?

Graphics and GPU Programming Programming

Started by Kekko February 10, 2005 10:32 AM

2 comments, last by Sander 19 years, 2 months ago

504

Author

February 10, 2005 10:32 AM

If you just add the color values when doing alpha blending, does it matter if you draw the front window first and back window then or vice versa? Would the visible result be any different?

Namethatnobodyelsetook

1,260

February 10, 2005 10:34 AM

If you're doing add, then no, order doesn't matter if ZWrite is disabled. If ZWrite is enabled, nearer objects may cause z rejection on further objects, stopping them from adding.

Kekko

504

Author

February 10, 2005 11:12 AM

Whew, that's what I was hoping for. Thanks!

Sander

1,332

February 13, 2005 09:00 AM

That's true for additive blending yes, but if you are drawing materials like windows then you normally don't do additive blending. In that case you need to draw your transparent surfaces back-to-front after all the other (solid) geometry has been drawn.

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Sander Marechal<small>[Lone Wolves][Hearts for GNOME][E-mail][Forum FAQ]</small>