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View Full Version : Alpha Channel Always Renders!?!?!?!?


Michael_Kasper
02-10-2005, 04:45 PM
I have been all over every thread so far about this problem and no one has really helped me out. The problem is very strange........um......I created a textured image in photoshop, created an alpha channel and saved it with an alpha channel. Then I loaded into maya as a color attribute for my shader and it shows up in my viewport perfectly, the transparency is exactly where it should be. When I render the image however the parts that were being displayed as transparent in my viewport now show up black and semi-transparent. I have tried the reverse node and went into all this trouble in the connection editor that I dont think is necessary,.......someone please help.......thanks.

Michael_Kasper
02-10-2005, 05:54 PM
I even downloaded a file from the net that included an alpha channel, still didnt work. So I know I'm not doing something wrong in photoshop, its got to be maya......weird......really weird..........please help.

Jackdeth
02-10-2005, 05:58 PM
Plug the out_alpha of the texture node into transparacy of the shader. Don't turst that BS hardware display when trying to guess what a software render will look like.

Michael_Kasper
02-10-2005, 06:48 PM
same problem......jesus....this does not look good.

floze
02-10-2005, 07:22 PM
When I render the image however the parts that were being displayed as transparent in my viewport now show up black and semi-transparent.
The filenode's out_transparency should be plugged into the shader's transparency.

Michael_Kasper
02-10-2005, 07:31 PM
What is the difference between the file's alpha output and the file's transparency output? thanks guys.

Michael_Kasper
02-10-2005, 07:42 PM
Hey floze listen to this......When I load the file into the color attribute of my shader it automatically loads the transparency settings into the transparncy attribute, so I have two connections from file to shader automatically, 1 being color and 2 being transparency. When I delete the transparency connection and then reconnect the problem seems to be fixed. There must be some kind of stange bug in maya. Thanks for your help...

floze
02-10-2005, 07:48 PM
What is the difference between the file's alpha output and the file's transparency output? thanks guys.
Transparency is RGB (3x8bit per pixel channels, together 24bit), alpha is 1x8bit per pixel channel. :)
That's why I called the alpha a 'value' - it has only one channel, or detailed: 2^8 = 256 grayscale variations (one bit is either 0 or 1 and you have 8 possible combinations per pixel and channel).
Out_transparency is also 24bit (or type float3).

Hell that was fun to explain! :D
I hope this was correct?

floze
02-10-2005, 07:51 PM
Hey floze listen to this......When I load the file into the color attribute of my shader it automatically loads the transparency settings into the transparncy attribute, so I have two connections from file to shader automatically, 1 being color and 2 being transparency. When I delete the transparency connection and then reconnect the problem seems to be fixed. There must be some kind of stange bug in maya. Thanks for your help...
I remember I had that once too I guess.. maybe a maya interface bug. Did you click on the icon next to 'color' or did you drag the filetexture over it? Does it anyway make a difference?

Michael_Kasper
02-10-2005, 08:31 PM
I clicked the icon to load the texture. Jesus, this really slowed down the progress of my little project. What I'm trying to do is make some hair out of bunch of mapped poly strips, I don't know, I've never done it before, hope it turns out ok. Any tips regarding that would be great.....if you want you can check the thread in the wip forum.........thanks a lot, you helped me out, this community is great.

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