White edge in compositing

[Crayox13]

Hi,
how do I get rid of these white edges? I always add background in post.
Usual suspects were MAX environment background but it's off, antialiasing filter - also off...

[glorybound]

I recently had these bad in an exterior, which I had to paint over in PS

[Morbid Angel]

this happens for a few reasons. Did you render against black? if not you should as it will be premultiplied in the alpha and so compositing anything will produce an edge. Also depending on what program you use to composite this in, there are various alpha options, like premultiplication of the alpha is important. Is this window - glass? if so three could be more then just alpha issue there - refraction...

[Pixelcon]

I usually render on black and use layer > remove black matte in PS. Seems to work pretty well...

[Crayox13]

Thanks!
I render against black but I always put vraysky in GI environment but also in the second slot reflection/refraction override. When I turned that off white edges disappeared Will have to see if I can go without it in my renders.

Also, removing white or black matte in PS doesn't seam to work since this is not an exterior edge but part of the glass so not pure black/white alpha.

[Pixelcon]

Thanks!
I render against black but I always put vraysky in GI environment but also in the second slot reflection/refraction override. When I turned that off white edges disappeared Will have to see if I can go without it in my renders.

Also, removing white or black matte in PS doesn't seam to work since this is not an exterior edge but part of the glass so not pure black/white alpha.

aah ok. This bg compositing issue has been around for far too long. The whole thing needs to be simpler :/

If worse comes to worse you could render without glass then do a second pass I suppose.

[Morbid Angel]

well it happens because the sky is embedded into refraction probably. Did you try checking in the vray material under refraction options - affect all channels to all.

[dlparisi]

Put your glass material into a VrayOverride material and duplicate (copy) it into the refraction slot. Then add a black Vray Color in the environment slot of the override material. I think this will give you what you're looking for. See http://forums.chaosgroup.com/showthr...-with-VRay-sky

[Crayox13]

I tried both affect all and colour+alpha and it was the same.

BUT, dlparisi it WORKED! Now I get perfect edges! Thank you!!

[dlparisi]

I tried both affect all and colour+alpha and it was the same.

BUT, dlparisi it WORKED! Now I get perfect edges! Thank you!!

Glad to help.

[RobH22]

I know this is and old thread but the issue crops up in modern times too. I'm using VRay 5 and dropping a background in the Frame Buffer as a layer. I had a strong pure white aliased edge around my objects. All I had to do was make the 'Background' color in 'Environment and Effects' black and is solved it. No muss...no fuss..