Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Njen on 2018-06-03, 01:46:45

Title: Multiple env lights...
Post by: Njen on 2018-06-03, 01:46:45
I want to be able to illuminate my scene with two HDRI's, and to be able to have light selects for them.

For example, I want to split my sky into top and side, then be able to dial them in separately.
Title: Re: Multiple env lights...
Post by: sprayer on 2018-06-03, 11:17:40
I am sure if you can make what you  want via mix node, or you may use this plugin to make own hdri by combining different light and textures https://www.lightmap.co.uk/hdrlightstudio/features/
Title: Re: Multiple env lights...
Post by: Njen on 2018-06-03, 23:40:23
That is not relevant to what I need.
Title: Re: Multiple env lights...
Post by: pokoy on 2018-06-04, 11:54:41
Would two very large half-domes with a LighMtl do the trick? I don't think you can set up two different environment systems. You could use the Composite map, sure, but they wouldn't be separate in the Light Mixer, working around this with geometry is worth a try.
Title: Re: Multiple env lights...
Post by: maru on 2018-06-04, 15:15:53
This is currently not possible (or at least I am not aware of any workaround) because there is no dome light in Corona (and no plans to add it).
I am really not sure if that would work at all, because rendering would take at least twice as much time as with 1 hdri only, and the extreme intensities (like turning one hdri to 0) could cause a lot of noise or some other artifacts.
But who knows, maybe one day... ;)
Title: Re: Multiple env lights...
Post by: Njen on 2018-06-04, 18:04:23
No worries, thanks for verifying.
Title: Re: Multiple env lights...
Post by: mferster on 2018-06-04, 18:20:38
Did a little experiment maybe this will work for you, maybe not.

-Basically two cloned spheres with flipped normals surrounding your scene.
-an invisible box that defines the split between the two HDRI (driven by coronadistance map)
-Each sphere has a different coronalight material applied with a different HDRI slotted in
-the corona distance map  is put into the opacity slot for both light materials (you swap the color positions for the second material)
-add each sphere to it's own light select element

*Clarification edit
Title: Re: Multiple env lights...
Post by: Njen on 2018-06-04, 22:43:36
The multi sphere solution is a working solution, however in the previous tests I've done, it does take longer to get a clean image, as HDRI's are evaluated differently as light sources compared with geo (I'm sure a dev can correct/verify this statement).
Title: Re: Multiple env lights...
Post by: maru on 2018-06-05, 10:06:03
Huge sphere with light mtl is a no-no in Corona. It will give you a lot of noise, will steal samples from other lights, etc. But it's probably the only option to have multiple environs.
Title: Re: Multiple env lights...
Post by: pokoy on 2018-06-05, 11:11:14
I thought that LighMtl will be optimized and handled similar to lights and that it's self-illumination which will be sampled without any optimization and be a lot slower. It'll certainly be slower than HDR lighting but then again, if it's your only option...