View Full Version : Alpha Channel Help

09 September 2004, 12:12 PM
What douse a person do to get rid of them annoying white outlines from alpha channels because I have tryed everything I can and I am beating my brains out over here
the prosses of my makeing my alpha channels is

laso the image
fill the background with white
shit-ctrl-I to invert my laso
ctrl-c to copy the laso selected
goto channels tab and creat a new channel "alpha"
ctrl-v to past copyed laso to alpha channel
To fix this is I have been:

Selecting the main layer under the layers tab,
going to the channels tab and checking the "eye show layer box" on the alpha channel,
This displays a red outlined version of the alpha channel over the main layer.

With the red overlay active I select alpha channel to prompt it to paint on it and I
start to bring the edge of the red overlay closer to the parts of the alpha channel I want to showup, there by cutting out the white outlines I dont want.

This works but it leaves me with exstrealy jagged edgeds makeing the whole texture look like crap.


I have tryed to blur the outline of the alpha channel but this takes me back to step one, but this time I have large Fuzzy white outlines in the alpha texture :(

09 September 2004, 12:24 PM
I'm a little baffled but are you trying to remove a white halo from around a selection?

If so make your selection then go Select>Modify>Contract

New window will appear - specify the number of pixels you want to contract the selection by then invert selection and fill with black. This should do the job.
If you could post a pic or explain the end result you're looking for - I could probably help you further.


09 September 2004, 12:47 PM
lol sorry I get so deep into my work I sometimes exspect everyone to be on the same page ;) but yeah see im working on tree,grass,flower, mic models but I get the white out lines in my see through alpha channels here are somepicture

Here is a picture of the alpha texture active in 3dsmaxs' material editor see them white nasty outlines along the edge of what to showup in the texture? blah ugly :)

Here is a picture of the texture being used on a model and you can planly see the white outline in the texture and it become way more noticealbe in game play.

I am going to try your tip see if it works but hopefuly this help give a better idea of what im trying to get at.

09 September 2004, 01:20 PM
I presume the original texture sits on a white background then. :)
Your problem comes about due to the anti-aliasing of the flower to white background being different to the anti-aliasing of your selection, plus the selection might encompass some pixels that aren't necessary.
This results in the white halo you see around your image. You can solve this by shrinking the selection slightly with the contract command.

What I tend to do is:

Load the clover in PS and make selection of the flower/leaf/grass.
Use the contract command (of 1 or maybe 2 px) to shrink it slightly.
Use Ctrl+J to copy this selection of the clover to a new layer.
Make a new layer below this new layer and fill it with something like bright blue. If you've got stray white pixels they'll show up.
Go back and amend selection or contract further. Continue checking against blue background until happy.
Use this final selection to fill alpha material with white. Save out and test in Max.
You could also replace the white background of the leaf with a coluor closer to the base colour of your clover.

This should get rid of it (unless you're doing something special in Max's material editor).


09 September 2004, 01:40 PM
Aww yes you have been veary helpful, the contract command works WAYYYYYYY better than turing magic laso to like 10 and useing shift/alt to get the laso a tighter fit HAHAHA. BTW please have a look at my Job Opertunitys thread

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