Basic Comping of a Vray render

[kafka82]

Also, why is that when I save an image as exr, without using any color mapping, it gets automatically viewed with a gamma correction when opened in photoshop? Or if you do use gamma correction burned in, it gets double corrected. It seems that PS always applies a gamma 2.2 curve on an exr when you open it.

Hey flipside..did u fix the problem with PS?
Here the same...when I open an exr from vray it seems gamma corrcted (brighter) compared with the rgb color version.
Any solution?

[kafka82]

It seems a color managment problerm. If I assign my monitor rgb as color profile the problem si still there; But if i use Proof Color under the view menu (using my monitor rgb as proofing profile) the comping result is the same as teh rgb color one.

[flipside]

Hey I never sorted the PS thing out

Now I just bought after effects, but I have no clue on how to layer those render elements in a way as described by cpnichols. Since there is only one stack of layers, how can you comp them like this?



Thanks for any hints!

wouter

[Da_elf]

basically put diffuse and raw GI in a comp with raw GI multiplied over diffuse.

put diffuse and raw light in another comp with raw light multiplied over diffuse

in another comp put comp1 and comp2 and use ADD then add the reflections and specular

[flipside]

Ow yeah

But it is correct that AE doesn't have such a schematic thing? That looks pretty cool to see the structure of what you're doing.

[Da_elf]

its got whats called the flow chart. which really sucks as an editor but can atleast give you the view

[flipside]

ok will check it out!

[re:FORM]

I've tried looking through this thread but couldnt find my answer.
What file-type should I be using with After Effects?

As far as I could work out;
1. I cant use EXR 32-bit because there's a problem with vray and exr?
2. If I use RPF, I have to limit the file to 16-bit as AE can't read 32-bit RPF files?

Also, if I tick "Use real-pixel RGB data" when saving a 32-bit EXR, I find the images show up as black in AE. Is that to be expected?

[vlado]

There are no problems with V-Ray and .exr files in the latest releases of V-Ray (1.5 and 1.5 SP1).

Best regards,
Vlado

[rivoli]

What file-type should I be using with After Effects?

exr it's just fine. well, almost, AE (just like PS) can't read any channel you may have saved in it apart from R, G, B and A. so if you save an exr with a bunch of render elements out of vray, those won't show up in AE (there's a plug in that does just that though: http://www.fnordware.com/ProEXR/ ).
just remember to enable linear blending in your project settings, off by default at least in AE 7, don't know about CS3.

[re:FORM]

A) Ok, if I have "Use RealPixel RGB Data" ticked in my exr settings, AE and the max RAM player loads the images in black (file size suggests they are blank). Is it correct to say I should have this ticked to get the correct float output from vray? Why would ticking this button result in blank files?

B) With the following parameters I am almost getting the same result, but the lighting is slighltly darker in the AE comp than the vray output. Comparing my multiplied rawGI and rawLight channels, they match up with non raw equivalents.... leading me to think the problem lies when ADDing these two channels. (edit, UNTICKING linear blending solves this problem!)

C) Can I just run through some parameters and see if there's anything I have wrong. This might be quite handy as a roundup of the settings discussed in this thread.

In Max

1. enable gamma correction;
2. set the gamma to 2.2;
3. check the Affect Color Selectors and Affect Material Editor options.
4. Leave input and output bitmap gamma to 1.0;
5. Color Mapping set to linear 1/1
6. (Can I safely use sub-pixel mapping without clamp switched on?... I assume clamping colours results in a non float output)
7. Effect Background ticked (Is this relevant to linear workflow and AE?)
8. Render Elements - All elements have vrayVFB and Colormapping ticked. Multiplier = 1.0
9. EXR settings : FLoat 32-bit _ R,G,B,A ticked _ Use RealPixel RGB Data ticked _ Pre-Multiply alpha Ticked.

in AE

1. Project settings : 32-bits per channel _ Linear blending ticked _ Import/Output to 32bpc format as linear unticked.
2. Working space : None.

The composite.

(
VRayRawLighting MULTIPLY VrayDiffuseFilter (same as VrayLighting)

ADD

VrayRawGI MULTIPLY VrayDiffuseFilter (Same as VrayGI)
) 

ADD VrayRefraction ADD VrayReflection ADD VraySpecular

D) Is there a Vray channel that I can use to compare the addition of rawlighting*diffuse and rawgi*diffuse ?

E) And finally... Now that the result almost matches vrays output, I can now see a white halo around the AA between objects (not just when it AA against the bg.) This is visible when I Multiply RawLighting and DiffuseFilter. My intial thoughts are that this is related to the AA filter which for this test render is Area 1.5.

Sorry for the long post, but hopefully this overview of the whole setup should help other people get their heads round this workflow!

Thanks for all your help!

[re:FORM]

I noticed that I had unticked "color mapping" on my diffuse filter channel... on ticking it and rerendering, there is a dramatic difference in lighting (darker).

I thought that with linear 1/1 the color mapping option on the channels would have no effect?

[digtlpete]

You get the white halo around objects when you use the multiply blending mode. Using VrayLighting and VrayGI (adding them) should fix the halos. Hope that helps.

-Brian

[Seraph135]

Depending on the situation, you can also un-premultiply your diffuse and raw passes. Multiply there RGB channels together, then pre-multiply the result to get rid of the halos.

Tim J

[re:FORM]

Depending on the situation, you can also un-premultiply your diffuse and raw passes. Multiply there RGB channels together, then pre-multiply the result to get rid of the halos.

Tim J

I assume this fix is for removing halos on the edge of the objects against the background ? (pre-multiply refers to how ae handles the alpha isnt it? ) My problem actually occurs betweeen objects, so premultipying the alpha would not have any effect.