add face behind alpha face?


(chrisjengle) #1

I can’t seem to get my object with an add face option to appear behind my object with the alpha face option. I could do some really realistic effects if this were possible. I know that blender has problems with transparency sometimes, but what rules apply to trancparencies? what can and can’t they do? I’m also curious because I have some Ideas that might be able to take advantage of the bugs.


(z3r0 d) #2

put your alpha faces in a higher layer. Blender seems to (at least on this computer, which is odd about things on occasion) draw all of the opaque faces, then the alpha faces on a layer, then all the add faces on that layer, then the same on the next layer (alpha then add)… This allows shadows to be drawn before fences so that they are always seen behind. (if the shadow is in front of the fence it must be floating or something else is wrong)

I have thought about alpha faces a lot lately, and here is another trick:
alpha faces are drawn in the order they appear in an object. if you set this order, you can cause alpha faces to overlap correctly. to set this order seperate the alpha faces, and join them in the reverse order they should be drawn. If you have different faces for each side of the alpha face it is often possible to order them so that, for example a fence, or a tree are always drawn correctly. It requries a bit of thought, and more explination than I am going to put here.


(chrisjengle) #3

thank you very much. :smiley: