How to Remove Shadows?

[sahibzada]

Hi guys i have already posted one of my problem but i got no answer, luckily it is solved, did check the "Render Layers" in passes, it solved 100% problem of white one but the black one have some weird lighting with it. Posting some snapshots, any one have idea how to fix this problem ?

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Does it happen because all of  the parts are in different layers?

[andy.engelkemier]

yes. This is caused by antialiasing. It's hard to tell just by looking, but it appears to be a transparency issue. There's not Much you can do with that. The only thing I can think of that might help is duplicate each layer a few times and merge them back together.
Another solution would be to render them Also together and place that image behind. That will give you the pixel information you'll need.

If this is not transparency, but rather white, you can get rid of that too. Go to Layers, matting, and remove white matte. Defringe there will give slightly different results, so see which works better for you.

Why does this happen? Antialiasing shoots more rays at the image than pixels (slight oversimplification) in order to be sure the image isn't missing something. In one pixel, the computer figures out that your object only occupies maybe 20% of the pixel. So it averages that pixel. The way I described it, theoretically, if you overlap two pieces that were rendered it should end up equalling 100% when overlapped. But there are more complicated sacrifices taken that make the image look nicer. In Most cases, this gives a much more pleasant image. But when you want to assemble things, like you are doing, you'll get less desirable results.

Suggestion> for your case, I would render a clown pass, then use the magic wand with antialiasing turned OFF.
If you don't like the stair stepped edges, you could also keep it on, then expand the selection one pixel after each selection. This would cause the objects to Slightly overlap, but that would get rid of the transparency problem.

[angelina22]

Suggestion which is provided here to remove shadows is a good one.

[andy.engelkemier]

Oh, I totally forgot. Also, you can render about 4 times the size you actually need and the problem will be nearly eliminated as well. The bigger you go, the less noticeable it will be.