Introduction to Maya - Modeling Fundamentals Vol 1
This course will look at the fundamentals of modeling in Maya with an emphasis on creating good topology. We'll look at what makes a good model in Maya and why objects are modeled in the way they are.
# 1 30-06-2003 , 08:24 PM
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Alpha Decal

Hey Folks. Anyone who has been following my posts can see how I'm working my way through Maya. I'm now on mapping and am looking to figure out how to use an Alpha to determine which pixels on my map get applied, and which get ignored.

I'm used to 3DSMax where you just click a button to tell it to use or ignore the alpha. I don't ecpect it to be that easy in Maya, but I can't seem to find it anywhere.

Thanks,
-dann

# 2 30-06-2003 , 08:42 PM
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Maya will use the alpha by default pretty much.

# 3 30-06-2003 , 08:47 PM
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To clarify even more, it'll apply the image's alpha to the material's Transparency channel.


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# 4 30-06-2003 , 09:14 PM
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Well it's not so working the way I thought it would so what am I doing wrong?

To explain more clearly what I'm looking for is for the words in the image below "Alpha Please" to be mapped on my object, but the checker pattern be ignored due to the alpha.

Do I have to do something with the color balance? When I try it affects the whole bitmap, not just the alpha'd area. Should I be using Alpha Gain or Alpha Offset ? I've searched the docs and can't find any explaination of what these do. I've tried changing their values but I have seen no effect.

p.s. sorry the image quality is so poor, but 15K was hard to get to.

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# 5 30-06-2003 , 09:34 PM
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Make sure you're using a 32-bit targa. When you apply the image to the color channel, the alpha will automatically get mapped to the transparency channel.


Danny Ngan
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# 6 30-06-2003 , 09:36 PM
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I am using a 32 bit tiff. I tired Targas, no differece.

Nothing is automatically happening with the alpha. I've checked in Photoshop, it is there.


Last edited by Dann; 30-06-2003 at 09:42 PM.
# 7 30-06-2003 , 09:59 PM
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Try connecting the image file to the material's transparency channel. It should use the alpha channel.


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# 8 30-06-2003 , 10:09 PM
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Tried that, still uses RGB.

the only success I've had is by creating a duplicate projector utility and matching the links within the graph using Alpha istead of color. It works but what an ugly way to do it.

Everyone says Maya will use the alpha automatically, but I don't see it. I guess my have the "special" version.

# 9 30-06-2003 , 11:10 PM
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Sooo Close

OK, I see what you're talking about with automatically adding the transparency, but that's only if you don't want to do any projection mapping. For my project I need projection mapping and Maya doesn't seem to add the transparency as easily with projection maps.

However I GOT IT TO WORK. Anyone care to see how, feel free to download and check out the file.

Thanks for the hints along the way.

-dann

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File Type: zip seamonster.zip (14.9 KB, 164 views)
# 10 30-06-2003 , 11:28 PM
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You could also always go to your file node, and in your attribute ed., there is an effects twirl-down, and in that you can check INVERT ALPHA to get what you wanteduser added image


Israel "Izzy" Long
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# 11 30-06-2003 , 11:32 PM
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Sorry Rage, but I wasn't getting any Alpha, so inverting wouldn't have helped much.

# 12 01-07-2003 , 12:43 AM
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Argh!

I DON"T GET IT!!!

Every time I think I understand Maya, I get smacked down. I thought I had it working, but when I switched my multi-colored bitmep to black (which is what I need), it no longer renders. Is black illegal in Maya? It can't be, so what the hell do I do?

Anyone who understands alphas in Maya, please take a look at this file and tell me how on this green earth I can make the bitmap text appear as black on the blue plane.

Please don't tell me to paint blue into my texture map because this in only a test file that will lead up to the real file which needs to use an alpha as a decal.

Please help me! I've been trying to map this for about 10-12 hours!!! I'm on the verge of tears here.

Thanks,
-dann
user added image

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File Type: zip alphatester.zip (49.6 KB, 197 views)
# 13 01-07-2003 , 03:44 AM
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Ah, I checked your file, and none of your images match the image names in your shader's file nodenames?

BUT, I think I have an idea as to what you wanna do, so I'll give it a gouser added image

...be back...


Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS
izzylong.com
# 14 01-07-2003 , 04:05 AM
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That's weird. I just looked and they match when I open the file. I'm looking forward to what you come up with.
Thanks.

# 15 01-07-2003 , 04:29 AM
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I think the reason the black wasnt showing up was because your enviornment was black? maybe?

is this what you were after?

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