Rendering recomposition problem

[KiboOst]

Hi,

I'm doing rendering testing with render element to recompose the final pass with render elements inside Toxik.
Anyway I have some problems with a bit too much light into diffusefilter or rawlighting, can't get it to work.

What I do :
max2012, vray2.0, toxik2012, all x64
linear workflow all along (gamma in max for maps/display, color mapping 2.2/don't affect colors, openEXR with all render element, gamma 1.0, and a gamma2.2 viewLUT inside toxik)
I use max standard VFB

The REs I render out : All renderelements have colormapping checked, apart diffusefilter
- VRayDiffuseFilter
- VRayRawGlobalIllumination
- VRayRawLighting
- VRayRawShadow
- VRayReflection
- VRayRefraction
- VRaySpecular

Then in Toxik I do the following (* = mult, + = add) :
[(Diffuse * GI) + (Diffuse * Direct)] + Reflection + Refraction + Specular
I've also try Diffuse * (GI + Direct) which mathematically is the same, and indeed, same result/problem

I'm sure the problem doesn't come from reflection/refraction/spec. It seems to come from the (Diffuse * Direct) part. I've try with VrayLighting, uncheck/check colormapping in REs etc, can't get it.
Here are some screens of different parts :





error here, it is indeed RawDirect * diffuse !


Any tips, help etc would be very welcome
Thanks
Kib

[KiboOst]

Just a note, I don't think it comes from Toxik as I use standard mathops or blend&comp in add or multiply, pretty basic. So if some nuke user have some insight on this too.
Also the difference is a lot less than gamma 1 -> 2.2 so I don't think it comes from a gamma settings neither.

PS : If I use the exact same workflow in a very simple with boxes and spheres, some transparent, reflectives etc etc, all works well ! So there is something in this scene that cause this. I've check the materials where it bugs, it is some vraymtl in multi/subobject materials, shouldn't cause problems.

headaches there !

[KiboOst]

Ok, if I use the other way (no diffuse and no raw versions) :
GI + Direct + Reflection + Refraction + Specular
Now all works like a charm ! exact same render !
So is it something usual that diffuse*rawlighting doesn't work ?

[pg1]

the anti aliasing of raw passes makes them not usable for compositing. If you really require the raw passes the process is to take your GI or Lighting pass and divide them by the diffuse. This will give you a result similar to the raw passes but the anti aliasing will be correct.

[Richb]

@pg1 - We have been using Raw passes (Lighting & GI) for years (Half Float EXR's) and always have the fringing problem inherent to compositing with Raw passes

I have recently been trying to extract the Raw pass from my VrayLight and VrayGI passes as you describe above (Dividing them by Diffuse)

The problem I now have is that the result is nothing like my Raw passes from the Vray frame buffer, it looks more like an alpha (I have set After Effects to ignore alpha's for all elements)

Any ideas why this should be the case?

I consider myself to know a fair bit about the process of compositing but After Effects seems to be doing something it shouldn't

[Richb]

Edges problem

I think I may have fixed this, After Effects was doing something it shouldn't have been doing but only because I hadn't reconfigured my preferences and set it up for linear compositing after a fresh install

One small note is that the Diffuse needs to be above the GI and set to Divide, not the other way around as the above posts state (and my attachment above shows)

This leads me on to a new issue,

The 'extracted' raw gi (from dividing the diffuse and GI) is supposed to better to composite with or so I've seen in other threads. However, the extracted version has a horrible edge when compared to the Vanilla raw gi pass straight from vray...see pics below


GI divided by Diffuse = 'Extracted Raw GI'


Actual Raw GI pass straight from Vray

Any ideas? I'm trying this new method to combat the haloing/fringing that occurs when compositing with the raw passes but this has led to another kind of halo/fringe

Here is the difference between the raw gi and extracted gi


Difference

Any help would be greatly appreciated

Thanks