rendering artifacts (3ds max)

[renerudzinski]

Hello everyone. While rendering an interior scene in 3ds max I stumbled upon an issue which drives me nuts. I have two lights – first is a vray dome with included HDRI and second is a vray sphere light. I animated the intensity of the latter so it reminds a bit of a candle. At some values though the sphere produces black glitches or some other weird artifacts.

 

 

I uploaded this to give you a better idea. Artifacts seem most annoying on the chair fragment in the foreground and two stacked chairs in the background.

 

 

After turning on render elements: RawGI, RawReflection and RawLight black splotches can be seen in the last one. I tried upping all subdivs that I know of to no avail. Also removing reflection map and replacing it with just a generic reflection doesn't change much. From what I see problems appear on my reflective wood surfaces only.

 

 

The black artefacts disappear only when

a) I turn 'store with irradiance map' under the sphere light

 

b) when I remove the diffuse texture from my wood material (clean RawLight element)

 

c) switch off 'shadows' under vray global settings

 

 

 

I am thinking maybe I have erased some image data while editing the diffuse texture in photoshop and this screws up the render? The image looks allright at first glance though.

 

 

I will enclose more screens soon – first just wanted to know what would you like to see first?

 

 

 

Thanks for getting to this point!

Edited July 3, 2015 by renerudzinski

[Bruce Hart]

Hi Rene

it's obviously a bit hard to tell what's happening as everything is so dark. If you use very low level light sources in Vray, you are asking for trouble. Try raising all light values an order of magnitude and adjust the exposure of the camera to suit the look you need

[Chris MacDonald]

Agreed.

 

The image sampler works by analysing contrast between pixels; so if your render is massively underexposed then it isn't going to be able to do its job properly as the vast amount of the information will reside in the shadows/lowlights.

 

Correctly expose the shot, then colour correct it to achieve the look you are after in post (after effects, premiere, etc).