Black edges in GBuffer Comping

[panthon]

I am facing the same problem in combustion. Whenever you use a RAW* channel which should be multiplied, black borders appear visible in refractions, rendering the result useless. So it's a matter of not using any RAW channel at all?
In my case the offending composition is Diffuse X RawGI.

[vlado]

Hm....then there's a lot of simply useless elements there. And it gives away a LOT of control (beeing able to tweak ref falloffs, beeing able to balance gi and direct etc etc etc). I'll play around with it some more.

Thorsten

Well, people wanted those elements, so they are there I have always pointed out that using them for compositing will lead to problems, but no-one listens... You should also note that this is not a V-Ray specific issue, if you generate the channels with another renderer, the same problems will be there.

Also, there is a side use of the raw lighting and GI elements - together, they represent something like the Illuminance render element in 3dsmax.

Best regards,
Vlado

[instinct]

mind you am not going to give up on that....may the force (not da_force, but THE force ) be with us :P

Thorsten

[instinct]

just had another thought. why is there no coverage element ? would it be eventually possible to render out all channels set to filtering off and multiply them with a coverage element to get the AA in ? most likely bullshit...my mind is starting to wander...

Thorsten

[Da_elf]

i dont know why there isnt a seperate coverage element however there is coverage accessed though rla files

[instinct]

hmmm...yet another thought. The multiplying problem arises because the filtered elements are in front of black. hence pixels that are antialiased are actually getting black premultiplied in. what if it was in front of white instead of black ? Then we would see a (pixel a (0.5) * pixel b (1) = 0.5 (unchanged))...wouldnt we ?

Thorsten

[m_hinks]

Ive been trying to comp together an animation Im working on. Ive been using the same elements Vlado has said in this thread, but once they are all added together the image is far brighter then the straight render. Does anyone no a reason for this? I have Linear Multiply gamma at 2.2, burning LWF into .tga's. Could this be the reason?

Many thanks

[dimo]

Yes,

you have to composite in linear space and only gammacorrect your final image.

Best regards,
Dieter

[m_hinks]

Cool, so should I turn the gamma back to 1 and render the elements out as .exr files. Then in AE layer them back together and gamma correct the whole comp?

Thanks Dieter

[panthon]

Yes, u should do that, but beware of the dark areas, they might come up really noisy and badly antialiased when u pump back the gamma to its right value.

[instinct]

to fight that you can set the gamma in the linear Colormapping mode to 2.2 and tick "Dont affect Colors" Then it adapts the gamma only for the QMC sampler.

Thorsten

[panthon]

to fight that you can set the gamma in the linear Colormapping mode to 2.2 and tick "Dont affect Colors" Then it adapts the gamma only for the QMC sampler.

Thorsten

That's interesting! I will try it, thanks for the pointer, thorsten!


EDIT: Is this option only in the RC4? I cant find it on RC2...

[m_hinks]

Oh cool, Im on RC3 and cant find either. RC4?

[panthon]

Im really interested in someone confirming if this option is only available on RC4...Does anyone know it?

[DaForce]

RC4 only.

You would assume that if 2 people on RC3 cant find it