animation light flickering

[ryan_howell]

Had a quick question regarding flickering- finished a render and found some flickering in parts of my animation and wanted to confirm what I read from the documentation. I'm using both BF for primary and LC for secondary, in the documentation there is a "camera path" option that from my understanding calculates light cache from the entire sequence instead of per frame and wanted to know if this was meant to reduce flickering? obviously I could also increase samples but render times are already longer that I would like and I have a feeling its the light cache causing this as theres definitely enough samples and no noticeable sample quality loss.

[natalia.gruzdova]

Hello ryan_howell,

Can you please share how you denoise your animation? Do you use an external Denoiser Standalone Tool?

If not, or denoising animation we strongly advise to use external Denoiser tool that is included in every V-Ray installation and can be found in this directory:

C:\Program Files\Chaos Group\V-Ray\V-Ray for Rhinoceros\vrayappsdk\bin

The advantage of using it is that it blends better animation frames reducing noise and flickering, and apart from that you have more control.

In order to use it follow these steps:

• Use default V-Ray Denoiser;
• Image have to be saved as .exr or .vrimg;
• Denoiser has to be set to Only Render Elements Mode ;
• In VDenoise app you can browse and add all your images to denoise at once (similar to Batch render), select Engine and preset (similarly to how it is set in V-Ray itself).

Also, please take a look and suggestions on how to avoid flickering in animations:

• For interior renders or other complicated lighting situations, increasing the light cache Subdivs parameter makes the light cache smoother and more accurate; values around 2000 or 3000 typically work well.

• The Retrace option helps to reduce light leaks and flickering. For animations, a value of 8.0 works well.

For animations with moving objects and/or moving camera:

• Set the Subdivs parameter to 3000, Sample size to 0.01, Retrace enabled and Retrace threshold to 8.0.

As for the UseCamera Path option - it can help rescue some rendering times.

Let us know if you have any additional questions.

[ryan_howell]

Hi Natalia! sorry I missed your reply,

Never used the standalone denoiser tool before, I saved the frames as a tga so I will need to re-render in the format you specified? I will try using the denoiser tool you mentioned.

[natalia.gruzdova]

Sorry for the late reply from my side as well.

Yes, you will have to re-render in order to save the .vrimg or .exr file formats, because more information is stored in both of these formats, compared to .jpg, .png etc.

Then you can convert .vrimg to .exr if needed for further post-production. Here are the instructions.