After Effects: Black Halo After Precomping Render Elements

[alexxrust]

Hi! So I have a bunch of vray render elements rendered out of 3ds max on a black background in 32bit *.exr format. When I stack them with "add" blending mode on top of my background picture everything looks fine, until I precomp them. Then that black outline appears around the precomp. How to get rid of it?

 

I interpreted render elements as premultiplied with black. Tried "remove color matting effect" on precomp - doesn't work. Ofcourse I can set precomp's track matte to alpha layer, but I want to add effects such as glows and blurs which go beyond alpha to certain render layers. So how do you assemble passes properly in Ae?

[Francisco Penaloza]

Hi,

You don't need to interpret that ID passes, all what you care is the color from them, Multimatte elements will have better antialising plus it keep transparency. VRayMtlID you need to force to use AA and wirecolors works fine too.

Now what I usually do is select the color with Key color in after effects, matt the image that I need then precomp that and apply chocker or simple shocker, with will help you to have a little extra control to the edge.

[alexxrust]

I want to solve the problem at its root. Moreover, I think chocker won't work if my 3d model is rendered out with motion blur. By the way, I've noticed another strange thing. If you make a comp and set it's background to white and put all your render layers there, a black outline will appear too.

 

But if you put a white solid underneath all of the layers, that halo disappears!

 

I'm totally confused!

[alexxrust]

The only thing I can't understand is why if in the render elements precomp you add a background or a solid and put it at the bottom, the halo disappears.