Matte Shadow Grainy

[ChrisPryke]

Hey Guys, I'm having some problems with Matte shadows at the moment.
The shadows are coming out really grainy when I use a shadow capture plane under my objects.

As you can see from my images the 1st image shows the matte shadows being really grainy, and the 2nd one is just a standard material on the plane. Is there something Im doing wrong?

Im using 3ds max and Vray 3.60.04

[guillaumelepage]

I usually uncheck "receive GI" for my shadow catcher plane, takes a lot less time to clean up noise. Hope that helps

[ChrisPryke]

Cheers, but it didnt help with my problem.

[ChrisPryke]

Any ideas on this guys?

[Martin.Minev]

Have you tried reducing the noise threshold of the image sampler you are using.

Best regards,
Martin Minev

[anthonyh]

Side question... which way is better, using the Matte options in vray properties like the above or using a VrayMaterialWrapper with matte settings ?

[ChrisPryke]

My Max noise is set to 0.005

[simona.b]

I would like to get some information on this too, I find this problem is a major issue with GPU RT renderer. Rays per Pixel set to max 128 doesn't do that much, increasing noise threshold doesn't do anything. Final shadow is very noisy and unesable for commercial purposes. I'm having to resort to CPU Adv. renderer which is really slow... This topic has been posted before half a year ago, so I'm hoping it's going to be addressed in the next Vray version... Right now it's easier to not use shadow catcher, but quality suffers...

if anyone has found a workaround for GPU specifically, would be interested to hear...

[seandunderdale]

I have the same problem in Maya. The renders take hours and are grainy. Also, like in the top image comparison, the shadow catcher never retains the scene light colour and is grayscale.

[kosso_olli]

Same problem here. Alolong the way to 3.6.04, the matte shadow started to get grainy somewhere. We have to fix this with a noise threshold of around 0.002, which takes ages to render. Why is that, and can this be fixed?

[Alex_M]

I have the same problem too with Vray Next 4.02.05 for Max 2018. The only thing that helps is setting Noise Threshold at 0.001 which is kind of ridiculous. Shouldn't it be clean at a threshold of 0.005?

[Morbid Angel]

Yeah I think there is some issue there. I also experience strong grain in matte shadow, and only way to handle it is with really high dmc max subdivs and low noise thresh which puts the render time up there.

[seandunderdale]

I made this thread a while back relating to the issue in Maya. I dont think its only realted to Max.

[suurland]

I also have this issue

I found two ways to "fix" it.. in quotation mark as it isn't really a fix.

1. Use a very very low threshold, which makes the rest of the image take ages to render.
2. Set the background color to something brighter than black. But it has to be black else the rim around objects gets really bad.

/Thomas