Colour correction settings issue in VRay Standalone

[tushar_foyr]

I am exporting vrscene file from 3ds max and rendering it using vray standalone in linux. Exporting and rendering is working fine but color corrections (exposure, curve, white balance) which are applied in vray frame buffer are not being correctly applied by vray standalone. I am doing following steps for it -

1. exporting lut cube file in max script using #saveglobalccpreset ?colorsetting.cube?.
2. copying this file in linux system where VRay standalone is installed.
3. setting environment variable with appropriate values in Linux VRAY_VFB_LUT, VRAY_VFB_LUT_FILE .
4. rendering vrscene file.

with above steps I am getting image with white washed output. similar output comes in 3ds max vfb when ?convert to log space before ?? option is checked. I am not able to find way to disable this option (?convert to log space??) programmatically in Vray standalone which is active by default.

Please help me in fixing this issue.

[tushar_foyr]

Any update on this? Is it possible to control color corrections (especially "convert to log space...") through VRay standalone.
Or export the LUT cube file with desired setting from maxscript so that it will not get white washed even if log space option checked.

[Svetlozar Draganov]

It looks like Convert to Log space option is enabled by default and the bad news is that there is no way to control it via env.var.
I'll add a note into our system to export env.var. for that option.

As for now the best way to workaround that is to use Global Color Correction File (*.vccglb) instead of LUT (*cube) file.
Use the following two environment variables to specify *.vccglb file and to enable/disable it when rendering with Standalone:

VRAY_VFB_GLOBAL_PRESET_FILE_USE	Enable (1) or Disable (0) automatic loading of a global .vccglb preset for the VFB.
VRAY_VFB_GLOBAL_PRESET_FILE	Specify default .vccglb filename (string) to be used when loading automatic global preset.

[tushar_foyr]

Few days ago I had tried exporting vccglb via maxscript (vfbControl #saveglobalccpreset "colorcorrection.vccglb") and enabled above 2 env variables on standalone side. but didn't see any difference in output image.
Let me try it again, may be I have missed something. Will let you know if it works or not.

[tushar_foyr]

I tried same thing again but it seems this "VRAY_VFB_GLOBAL_PRESET_FILE", "VRAY_VFB_GLOBAL_PRESET_FILE_USE" are not used by vray standalone. I checked from my end vccglb file is correct and these 2 flags are also set while rendering.
Even in Standalone documentation (https://docs.chaosgroup.com/display/...ment+Variables) these are not mentioned. Please suggest me some workaround for the same.

[Svetlozar Draganov]

What is the Standalone version that you are using?

[tushar_foyr]

I am using V-Ray 3.60.04 ADV .

[Svetlozar Draganov]

I can guarantee that this version supports the environment variables above, here is a quick video for confirmation:
http://ftp.chaosgroup.com/support/sc...4_09-27-07.mp4

Please make sure that environment variables are set properly.

[tushar_foyr]

Actually I am rendering in ubuntu OS with non-gui mode with standalone -display = 0 parameter. I have tried applying env variables but no luck. Does it work on linux without gui also?

[Svetlozar Draganov]

Latest official version of V-Ray for 3dsMax doesn't support applying color corrections when VFB is disabled.
Support for that is already added but it's in the nightly builds of V-Ray for Maya only, I'll see how quickly we could port it to 3dsMax stables and will update you afterwards.

[tushar_foyr]

I am using VRay standalone for rendering in linux ( not vray for 3ds max). In VRay standalone also there is vfb enable/ disable option and I am rendering vrscene files with vfb disabled because I don't have gui installed in ubuntu server. Does color correction supported in VRay standalone with vfb disabled?

[Svetlozar Draganov]

Works fine even on headless machines with -display=0. Here is a test I just did with latest official version 3.60.04 on CentOS 7.
http://ftp.chaosgroup.com/support/sc...5_11-52-18.mp4

[tushar_foyr]

Have you used "curve color corrections" option also in this video? because for me some of the values of vfb settings are not getting applied. attaching sample vrscene zip and 3ds max zip file (vccglb file is also inside zip) for reference. Please check.

[tushar_foyr]

Any update on this issue? did you find time to check this sample scene?

[tushar_foyr]

Any update on this issue? Please have a look into it. It is affecting my work flow.