HDRI refl;ection maps are causing pixelated renderings?

[Kinetic99]

test file to resolve grainy issue.ziptest file to resolve grainy issue.ziptest file to resolve grainy issue.ziphere is the MAx file

[grantwarwick]

I'm at work so can't respond properly for a few hours but as suspected, your settings were incorrect and this is simply a sampling issue.

First of all, you were using a pure black value for the glossiness, you're going to need a shitload of material subdivs to tackle that. 512-1024 (Seriously)
I'll get into how to control the DMC sampler tonight

[Svetlozar Draganov]

The noise comes from Bump channel of materials applied to the sphere.
The scale of the map is very very small and at the same time its height is very high - if you change the height to 3 or lower the noise disappears.

[Kinetic99]

thanks for the first feedbacks..

First of all, I did not get this grainy-look issue with the exact materials in a trial version of 2013 and VRAY 1.5. Once I purchased 2014 and VRAY 2.0 and mgerged my scene in, I started noticing this rendering issue. It only occurs with this latest software.

Second of all, the grainy issue only occurs when HDRI maps are applied - in 3DS max environment slot or in the VRAY environment slot.. Once the environment is disabled, I do not get this grainy problem.

I'll admit, I can experiment and find more optimimzed settings for sampling and rendering, but for starters, this is not the inherent issue. The issue starts with the two points above. Please try using an HDRI map in the environment slot and compare.

Also, If I increase sampling to smoothen out the graininess, my rendering times goes through the roof. If I reduce my noise bumps, the desired look in not achieved ( I need close-ups of this material to show the noise bumps). Again, I did not have to do any of these in 2013 and VRAY 1.5

thoughts?
thanks for your time, K

[vlado]

We will check to see if there is anything wrong with this, but in general, if you put noise in, you get noise out...

Best regards,
Vlado

[Kinetic99]

[QUOTE=vlado;592684]We will check to see if there is anything wrong with this, but in general, if you put noise in, you get noise out...

Best regards,
Vlado[/QUhgi

Hi Vlado, Any look with the test? HDRI map in Environment and without?
thanks for your help.

[Svetlozar Draganov]

I've run another tests on your scene - but I am not sure if this is the result you are looking after.
Here is the result with HDR-image in the background with similar frosting appearance like the image without it.



This result could be achieved by decreasing the intensity of the HDRI image or adding a environment-override map for the frosted-shader.
In the example above I have used two versions of the same HDR-map - one in the Reflection/refraction environment with high-intensity and another one with lower intensity into environment-override slot of the material. The purpose of this work-flow is that you are now able to control the reflection of the frosted-material separately and by decreasing the intensity of the HDR image noise disappears.