Coronalight color bleeding

[walter_OCS]

Hello everyone! I understand the question may be strange, but for specific cases I need to manipulate the color bleeding of Corona Light. That is, if it's visible at 3500 kelvin, it should be white in GI. Is it possible? Is there a way? Thank you in advance.W.

[TomG]

Usually done at the material level, using the Ray Switcher, though usually requested and used to for example make the reflected light from a red sofa less red. So it isn't tied to one particular light but how the material feeds into GI. Other than by material, I can't think of a way it would be done, so you couldn't have the light act one way in direct and another in indirect.

[walter_OCS]

thanks for the answer. In fact we need a light-color-switcher that works like the rayswitchmtl. but I realize that it's complicated or impossible.thank you.W

[Juraj]

While GI is material function (since light gets bounced color only once it bounces from something), you can affect direct light color.

But it doesn't work with RaySwitch material, I tried many ways to do it with single LightMaterial and it doesn't respect GI/Visibility override for some reason, the GI always becomes visible.

But you can do two LightMTLs (I am using Light Material instead of Corona Physical Light because it has option to not cast light):
1) LightMTL 1: Casts Light but isn't visible, can be 6500K true white.
2) LightMTL 2: Doesn't cast light, but is visible. can be nice 2800K warm white.

In regards to reflection, a choice has to be made which one will be reflected (which also affects specular response of material, so it's not just visible in reflection option like Vray has).

[walter_OCS]

thanks jiuraj. I also tried to concatenate a series of coronalightmaterials in a coronarayswitch, but it doesn't work. I also thank you for your suggestion, which I will certainly use. Actually what I'm trying to achieve is this: imagine a corona light with an ies map of a narrow cone spotlight illuminating a piece of furniture or an object. where the light strikes must be at 3500 kelvin but the GI must be white. For example: imagine a total white showroom with hundreds of spotlights at 3500k, everything would turn yellow. if we could find the trick to make the GI neutral everything would be well balanced.

[Juraj]

I think someone wrote a script to put every material into RaySwitch, can't remember more. Corona isn't MentalRay/Vray so GI Saturation parameter doesn't exist.

One more thing to simulate it perhaps, is to render in passes and lower saturation of GI-Pass. Sadly GI pass doesn't contain just pure light information, but Albedo+GI Light, but if you use something like Vibrance in Photoshop you should be able to do some trickery maybe.
You could then focus on making only the big materials (walls & floors) into RaySwitch with B&W Albedo map in GI.

[walter_OCS]

Again, thank you. I hope in the future I'll find a way.