LUts no longer work correctly

[Joelaff]

So LUTs were working fine. I could create one from the VFB and then apply it in Player. All worked great.

Now LUTs look as though they are being applied in integer space, rather than accessing the float data. Restarting player does not help. This happens with both EXRs and vrimg files. The files load fine in Fusion, and I can apply the same LUT there with no problem.

Is there a setting someplace that I may have changed that sets Player to work in int (like djv has a setting to convert everything to 8bit on import). But... this is likely not the issue because exposure and soft clip work fine, and I can reveal values that are > 1.0 with no problem using them. I just can't get LUTs to work right anymore.

What is the best way to clear all preferences to kind of "reset" player to see if I have a bad settings file someplace?

Thanks.

[yolov]

Can you tell me what version of Player you're running?
If you're on the latest - do you remember in which version it worked as expected?

One thing I recall we've changed in the latest version is making color mapping settings persistent per file type. Not sure it's the cause, but it may be related.

To see if a 'factory reset' does any good in this case, you can try (backing up and) deleting this file: C:\Users\<USERNAME>\.chaosplayer\chaosplayer.setti ngs.dat

[Joelaff]

Thanks for getting back to me.

Using the latest release version.

I know it worked at one point in this same version. And now it died not. I eventually found and deleted the directory you specify. This did not help.

I didn’t see any new versions in the nightlies since October I think it was. I guess there are not many builds happening on Player??

[yolov]

Can you show me an image that illustrates the problem?
Also is it with a specific LUT (can you share it) or any LUT exported from the VFB will do?

[Joelaff]

I can show you in a little over a week when I am back to the office. Or I may be and to try remotely with a vpn.

Any LUT. out of the vfb. Including a LUT that was most definitely working.

It’s possible the issue is with the “raw” multichannel EXR files saved from the vfb during animation rendering. But I think I tested shorter EXR and ruled that out.

It’s weird because the same LUT and exr work just fine in Fusion. Maybe there is something weird with the alpha channel (not 0-1.0). But the issue affected the entire image, and again it works fine in fusion. And it DID work in Player. That’s the really weird thing.

[yolov]

Just bumping up this thread to see if you've had the chance to check on this.
I've also spent some looking into this and testing a few different scenarios - there is a chance that some settings need to be adjusted, so do let me know when you get the chance to check on this.

[yolov]

Hey Joelaff , coming back to this - do you have any examples you can share?
I'm trying this with all Chaos Player versions and the latest available PDPlayer and I'm getting the same results between them - I don't think the behavior changed. Still, it seems that the result might not be quite right, but I'm just hoping to get some examples to confirm.

[Joelaff]

Sorry, been out of town for multiple shoots, and very busy. Do you have a LUT that you KNOW works there? Perhaps I could try that? I am wondering if it is the LUTs generated by the VFB, which apparently are just linearly interpolated past 1.0

[dlparisi]

I can't seem to get this to work either (may be user error though as I'm new to Chaos Player). I'm exporting an animation from Max 2020 and Vray 6.1 via the V-Ray Raw image file in the frame buffer setting (I get a sequence of vrimg files). I have the "Save VFB color corrections to RGB Channel" unchecked in the save as dialog box. When I load these up in Chaos player 2.10.01 the color corrections from the Vray VFB do not seem to be loaded up (as expected). I then export a LUT file from the VFB via right clicking on Display Correction and "Save all CCs as LUT". Loading this .cube file into the "Lookup Table" under Color Mapping in Player results in an image that looks like it has incorrect gamma or something (i.e., it's washed out). So how do I get the Player version to look like the VFB?

[yolov]

I think we'll need to look into this a bit more. I can reproduce what you're describing. It will be best to examine this a bit closer.
Added CP-311 to our issue tracker, you can use this number as a reference in the future.

[Joelaff]

That is what I was encountering. If you can reproduce it, terrific. I hope we can figure it out.

Thanks.

[dlparisi]

I think we'll need to look into this a bit more. I can reproduce what you're describing. It will be best to examine this a bit closer.
Added CP-311 to our issue tracker, you can use this number as a reference in the future.

Great. Even a temporary workaround or a pointer to know if it's a problem with player or Vray VFB or the cube file. I've tried to do this in AE as well and I get the same double gamma when applying the .cube LUT.

[dlparisi]

FYI - I got the .cube file to work as expected in AE. I needed to set the "Linearize working color space" in the project color settings. With this set, the raw file - I needed to use an .exr though rather than a vrimg - and .cube LUT matches the corrected VFB image. Works fine in Photoshop as well. Still can't get it to work in player though.

[yolov]

FYI - I got the .cube file to work as expected in AE. I needed to set the "Linearize working color space" in the project color settings. With this set, the raw file - I needed to use an .exr though rather than a vrimg - and .cube LUT matches the corrected VFB image. Works fine in Photoshop as well. Still can't get it to work in player though.

That's a good tip, thanks!

[yolov]

Great. Even a temporary workaround or a pointer to know if it's a problem with player or Vray VFB or the cube file. I've tried to do this in AE as well and I get the same double gamma when applying the .cube LUT.

It's a problem in Player. The LUT that the VFB saves should work fine.