Maya Fluids - Splotchy noise

[MF_Danny]

Hi there,

So I'm currently working on a project that I'm using Maya fluids (unfortunately I cannot use Phoenix as we are all on MacOS). I've got a relatively highres sim all cached out with a Vray Fluids attribute on it. I've currently got 'use LC' enabled, which I know from the documentation can cause some issue if noises are used or the sim is low res.

I'll attach some images, now I can turn the Ph LC off but I then get large render times. As you can see I'm already at 40mins for an image I'd ideally like to get some more noise out of. Now I'm not looking for miracles in terms of render times, more so just some help to get rid of the splotchy noise and try to tame the render times if possible.

Maya 2018.3
Vray 3.60.04
MacOS 10.13.6


Cheers,
Danny

[nikolay.kusht]

It would be best if you could share your scene so we could take a look.

[MF_Danny]

Hi Nikolay,

Thanks for getting back, I'm currently uploading a zip to wetransfer to support@.

Cheers,
Danny

[nikolay.kusht]

We have received your scene and we will look into it shortly.

[nikolay.kusht]

I have run a few tests with the latest scene that you have send us. Because there were only two frames of the cache I am not certain if I managed to remove all of the flickering, but as for the general noise, there have been some improvements.

You could try changing the "Min subdivs" of the image sampler to a value of 2 or 3. Also, you could decrease the "Noise Threshold" to 0.005. I have also, changed the "Min shading rate" back the default value of 6.

"Use light cache" option from the V-Ray Fluid Attributes may give you some performance, but is most likely the reason of the splotches to occur. It would be best not to use it.

[seandunderdale]

" I have also, changed the "Min shading rate" back the default value of 6. "

Is this a value you'd suggest using generally? Ive always left it at 6 for everything, but Ive recently had some colleagues suggest higher values such as 12 for default.

[MF_Danny]

" I have also, changed the "Min shading rate" back the default value of 6. "

Is this a value you'd suggest using generally? Ive always left it at 6 for everything, but Ive recently had some colleagues suggest higher values such as 12 for default.

Yeah you don't really need to change it that much, I had only moved it from 6 because I had a very shallow depth of field and wanted to see if that had an impact on the render times. It's still dependant on what's in your scene, but overall leave it at 6