Alpha Channel Trouble!
by Basil Goncharov · in Technical Issues · 12/07/2003 (6:49 am) · 8 replies
Hey, people!
Can anyone tell me what's wrong with v12?
I have a problem: when I map a texture with alpha transparency to the simple "billboard" (X - style) tree model and look at it in v12, i sometimes can see some polygons are drawn in incorrect order. (e.g. polygon should be farther, but it's drawn on top of other poly)
I've seen this bug on various machines, so it isn't a configuration problem.
BTW, I see the same problem in sample maps (scorched planet)
Can anyone tell me what's wrong with v12?
I have a problem: when I map a texture with alpha transparency to the simple "billboard" (X - style) tree model and look at it in v12, i sometimes can see some polygons are drawn in incorrect order. (e.g. polygon should be farther, but it's drawn on top of other poly)
I've seen this bug on various machines, so it isn't a configuration problem.
BTW, I see the same problem in sample maps (scorched planet)
#2
Well, I've looked at Torque, the bug is still there :-(
So, how can I change that SortOrders? (If I can, of course :-)
12/07/2003 (7:57 am)
Ben, thanks for answer.Well, I've looked at Torque, the bug is still there :-(
So, how can I change that SortOrders? (If I can, of course :-)
#3
12/07/2003 (8:10 am)
Wasnt it to do with how the models are exported or something? I think you have to set a flag when you export it (in 3D MAX that is). Theres some info in the documentation I think. 
#4
To correct this you can add "Sort::" in front of the name of your model, though there are some important notes that you need to know before doing this:
- The sort tag essentially sub-divides the mesh upon export so that it is drawn correctly. As such you want to sort the least amount of polygons as possible. So in your case only the leaves.
- Doing a sort on anything that you export will take longer to do.
12/07/2003 (11:57 am)
Yes this indead sounds like the "sorting" issue.To correct this you can add "Sort::" in front of the name of your model, though there are some important notes that you need to know before doing this:
- The sort tag essentially sub-divides the mesh upon export so that it is drawn correctly. As such you want to sort the least amount of polygons as possible. So in your case only the leaves.
- Doing a sort on anything that you export will take longer to do.
#5
L Foster: thanks for the tip, I'll try it tonight and will post about the result.
12/09/2003 (11:58 am)
Dylan: I looked at the standard objects (trees in Torque demo), they have this problem too. So I don't think it's purely 3DMax issue.L Foster: thanks for the tip, I'll try it tonight and will post about the result.
#7
And I've got an idea why is this happening:
when I export without "SORT::", converter optimizes my mesh to strips, and it cannot decide which polygon to draw first.
But if "SORT::" is present, converter just removes unneeded vertices, so polygons remain apart and can render correctly.
Well, it's only my humble opinion :-)
Anyway, I think the problem is solved, and I say thanks to you folks.
12/09/2003 (1:32 pm)
I made it, it works!And I've got an idea why is this happening:
when I export without "SORT::", converter optimizes my mesh to strips, and it cannot decide which polygon to draw first.
But if "SORT::" is present, converter just removes unneeded vertices, so polygons remain apart and can render correctly.
Well, it's only my humble opinion :-)
Anyway, I think the problem is solved, and I say thanks to you folks.
#8
12/09/2003 (2:39 pm)
Actually, SORT splits the shape into several smaller polygons that will sort correctly. 
Associate Kyle Carter
It's probably a bug in the SortOrders for those object types, or maybe the models...