Blotchy renders

[ryanlewis1]

Hi all

 

I am in the process of recreating an underground scene and have noticed that there is a blotchy effect on all of the materials (image attached) DO any of you guys have any suggestions as to why this is happening.

 

Thanks

 

[pablovergara]

Check that you're not forcing vray too much by lighting your scene correctly. Then check your GI settings. It looks like an irradiance map problem.

 

 

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[Francisco Penaloza]

yea, that's GI problems usually, a larger interpolation on the IRR would fix that, but when you increase the interpolation you also need to increase the samples numbers or you would lose details.

 

As mentioned by Pablo, this is more common when lighting is very dimmed and GI has to work double.

I would try Brute force in the firs pass and LC as the second bounce.

Use a large number on LC, it is very cheap for still images, so 2600 samples or more should help brute force

[ryanlewis1]

Thank you for your responses. It was indeed bad lighting. There was a dark hdri attached to the dome light, once removed the blotches disappeared. Thanks!

[Graphite]

2600 Samples for LC is way to high. I've never kicked it past 1200.

Properly balanced Samples for lighting and materials will help keep images looking clean and render times down. Step in Increments of (x2) starting at 32 (IE: 32, 64, 128)

 

Interior Images hardly ever need Antialiasing, so I keep it off.

Global DMC set at 64 Min Samples

Irradiance Map in the GI Set to Med. Preset

 

I use these settings as my base. Render times are pretty quick for even large scenes at 1920x1080.