Game Development Community

Maya models: Transparency problems

by BJNelson · in Technical Issues · 04/20/2005 (1:43 am) · 16 replies

Hi,
I've looked extensively through the forums already and haven't found any solutions to my problem, I hope someone can help!

My problem:

When I have objects with transparency applied, intersecting eachother, it looks like the objects are inside out. Basically the transparency bcomes messed up. This only occurs if both objects have transparency applied and are intersecting eachother. See image for an example.
www.myfilehut.com/userfiles/nitai/help.gif
I'm using Maya 6 and exporting with Danny's .DTS exporter (great work by the way Danny). I'm using PNG's with alpha maps, created in Photoshop 8 with the SuperPNG plugin.

Based on what i've found in the forums, it seems other people are having the same problem with Max and that it's something to do with the way the objects are sorted. I've tried switching the hiararchial order of the objects in Maya with no success.

Has anyone else had this problem when exporting from Maya, and did you solve it? Any help would be much appreciated.

thanks,
-matt
NextNext Thread
PrevPrevious Thread
More from Technical Issues


Torque Owner timmport
#1
06/16/2005 (11:39 pm)
Hello.
I have this same problem and wonder if you discovered the solution since you posted this.
Thanks

Torque Owner Danny Ngan
#2
06/17/2005 (12:30 am)
You can add SORT_ to the beginning of the names of all meshes that have transparent textures. That should force the exporter to account for the transparency sorting correctly.

Torque Owner timmport
#3
06/19/2005 (5:56 pm)
Hello Danny.
Thanks a lot for the quick response and I really appreciate you creating this plugin for the community in the first place.

I added SORT_ to the begining of the name of model then exported it as a dts from Maya 5. The draw order problem does seem to be resolved. However the opacity of the areas that are meant to be opaque is only partial. I generated the PNG's using the SuperPNG plugin and they work fine when placd in a web browser. The following image illustrates the png transprency issue.
www.timportlock.net/torque/sort_order.png
Any suggestions would be very much appreciated .
Thanks again.

Torque Owner Charl F Bachuis (CF)
Default Studio Name
#4
07/11/2005 (11:38 am)
I also have same problem. But I am using maya 6.5. Even after adding sort_ to the model names, I still have the sorting issue in showtool.

I dont know if the exporter is final for version 6.5 of Maya. But so far thats the only issue I have experienced.

A solution for this would be much appreciated.

Thanks

Torque 3D Owner Daniel Eden
#5
07/12/2005 (4:53 pm)
I ran into the opacity "issue" the other day and there's a fairly simple fix. Simply unlink the texture's alpha channel and the material's transparency. (You can do this through the hypershader).

Torque Owner Charl F Bachuis (CF)
Default Studio Name
#6
07/13/2005 (12:24 am)
OK, Ive just tried that, the sorting is fine, but not transparency then. This appears to be an issue with Maya, when you use and transparency on a single mesh that has 2 normals facing in the same direction. This does mess up the mesh, and it also exports wrong.

Torque Owner Allan Stewart
#7
07/13/2005 (7:53 am)
Try doing the png transparency up with out the direct alpha channel.

www.garagegames.com/mg/forums/result.thread.php?qt=30515

Associate Manoel Neto
Default Studio Name
#8
07/13/2005 (9:19 am)
In my experience with 3D, having a whole mesh with non-conves features with an alpha channel texture does produce problems in most engines/system.

The easiest way around this is implementing alpha-test on the engine.

Rdi
#9
10/12/2005 (8:20 pm)
I'm using maya 6.0, and using JPGs textures with other JPGs alpha cannel.
I also have same problem

Torque Owner Allan Stewart
#10
10/13/2005 (11:13 am)
JPG images doesn't support alpha channels, You need to use png and or tga textures for the alpha , channel , PNG being supported more for GG

Rdi
#11
10/13/2005 (6:16 pm)
I using two JPGs textures,one for color channel,another for alpha channel.
Like the demo of Torque.

Torque Owner AllynMcelrath
#12
10/16/2005 (3:16 pm)
Transparencies are wonkey in Torque, they say they are not broken, but i have my doubghts.

They say there is an article comming out on the the new TDN, whenever that comes out. There are 100's of posts on the subject.

I still have not found a viable way to fix them yet, i have gotten closer, but its still wonky in ways it realy should not be.

I curently use a program called M-Sort, but i think its lightwave only. and it still dosnt fix all the issues, single objects still render backwords even when seen threw its self. and that has me compleatly stumped.

Torque 3D Owner Todd Pickens
#13
10/16/2005 (4:19 pm)
A word of caution about using the SORT command. Depending on the instance for which it is used, it can dramatically increase you poly count of the object is applied to.

Torque Owner Andrew Grant
#14
10/25/2005 (2:13 pm)
I was having sorting issues with a character model and I found a solution that works, with Maya at least. You need to change the order of nodes in Maya. Do a search for "order of nodes" in the Maya docs to find a tutorial. It's CTRL + MiddleClick and drag in the hypergraph.

My character had transparent polygons floating in front of the head. One piece was for the eyebrows and the other piece was the eyes. We want to swap textures to get animated eyes and eyebrows. To get it to render correctly, the nodes have to be ordered properly in maya's hypergraph. From left to right, since the eyebrows were over the eyes, the nodes need to be eyebrows, eyes, head. I believe that this makes the head render first, then the eyes, then the eyebrows.

Hope that helps.

Victor Valentine
#15
08/23/2008 (2:11 pm)
The SORT_ command crashes my maya on export. Any ideas?

Torque Owner Greg Gardinier
#16
10/04/2008 (5:59 am)
To my knowledge the SORT command is broken in the Maya exporter. This is really unfortunate and there is no real way around it. Your only option is to fix it yourself in code or use 3dsMAX.