Vray stuck on "compiling adaptive lights"

[noah_davis1]

I am trying to use the interactive render but whenever I do so the render quickly gets stuck at "compiling adaptive lights" and the image switches to this blurry, mushy mesh that's like an AI approximation of what the image is supposed to look like.
I'm using default settings, medium quality, low resolution.

See this video below for what's happening when I click the interactive render button. It quickly goes through the early rendering steps and then hits this point and just stops.

If I switch to GPU rendering from CPU rendering, the "compiling adaptive lights" issue seems to disappear, however I am still having the problem where the image switches to this blurry mess and never progresses past that.

[konstantin_chaos]

Hi noah_davis1,

The blurry result you are referring to is the denoised image.
Note that this image is not stuck, it's updated with every sampling pass that V-Ray traces.
You can disable the denoiser if you would prefer to see the raw noisy image during interactive rendering.

Also, I don't fully understand what gets stuck.
What happens if you change the view while you're interactive rendering?
I expect the image in the VFB to update.
Same should happen for any other scene changes.

Regards,
Konstantin

[noah_davis1]

Changing the view does update the VFB but it does the same thing, quickly changing to the denoised version which doesn't seem to change.

I understand that the denoiser is what is producing the blurry image, however the render never seems to progress past this stage. I can leave it for a long time and it will never increase in clarity or sharpness.

[konstantin_chaos]

Hi noah_davis1

I'm testing your scene, and all interactions are correctly reflected in the renderer. I'll share a video later to demonstrate the results.
If the camera isn’t moving in the interactive view, one reason might be that Lock Camera Orientation is enabled (represented by a padlock icon on the toolbar).
You can check the render logs to see if there are any errors or warnings printed too.

I also noticed that the V-Ray Denoiser is active, which isn't ideal for interactive rendering (The Intel one would be better).
Additionally, the Light Cache prepass is affecting the interactivity - switching Secondary GI to Brute Force might improve responsiveness, especially in GPU mode. You can play around with this and see if it's better.
If possible, I recommend using the CUDA GPU engine, as it allows your CPU to contribute to the rendering process, which I suspect would make a noticeable difference in your case.

While testing, I identified several additional potential optimizations we can explore. We'll use your project as a benchmark for further optimisations.

Regards,
Konstantin

[noah_davis1]

What optimizations do you recommend? I have managed to significantly reduce the file size by purging the model and deleting some unnecessary geometry