Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: chado on 2019-11-15, 17:16:55

Title: Dispersion of light
Post by: chado on 2019-11-15, 17:16:55

Hello, everyone!
I have a question. Does anybody know how to make a dispersion of light from headlights?

Title: Re: Dispersion of light
Post by: maru on 2019-11-15, 17:51:39

In reality those are caustics, so you could model the headlight, enable dispersion for the glass (there is a dispersion checkbox inside a Corona Mtl), and enable caustics in the material and in Render Setup > Performance. But this may be quite expensive to render.
Another option is faking it somehow, for example using multiple colored lights.
Or you could try this: https://forum.corona-renderer.com/index.php?topic=11630.0

Good luck! [tm]

Title: Re: Dispersion of light
Post by: Br0nto on 2019-11-15, 19:07:22

For my headlights I added an invisible light blocker preventing the "real" lights from shining through, and then faked the headlight beams with IES lights positioned just outside the headlight glass. Then it's just a matter of finding an IES that looks right for your headlight type. I just eyeballed it, since I wouldn't know where to start to find an exact headlight spec IES. You could also use IES profiles for the spill near the car, while using larger, more normal beams of light for the primary focus.

Title: Re: Dispersion of light
Post by: chado on 2019-11-16, 07:08:54

Thanks for answers!

Br0nto, I used IES, but I don't know how to make fake dispersion.
I should use 2 or 3 IES with a different colors?

Title: Re: Dispersion of light
Post by: sprayer on 2019-11-16, 15:46:25

Br0nto
You can make own IES for example with this small program from Karba
http://lightonline.ru/files/Programs/IESGen4.rar (http://lightonline.ru/files/Programs/IESGen4.rar)

Title: Re: Dispersion of light
Post by: Br0nto on 2019-11-18, 15:34:25

Quote from: chado on 2019-11-16, 07:08:54

Br0nto, I used IES, but I don't know how to make fake dispersion.
I should use 2 or 3 IES with a different colors?

By "fake" I meant that the only light was coming from the IES and spotlights, rather than from any actual caustic/refraction effect coming from inside the headlights. I'm honestly not sure what you mean in this context. Both my lights were a similar color so it would appear that they are parts of the same light.

Quote from: sprayer on 2019-11-16, 15:46:25

Br0nto
You can make own IES for example with this small program from Karba
http://lightonline.ru/files/Programs/IESGen4.rar (http://lightonline.ru/files/Programs/IESGen4.rar)

Nifty, thanks!

Title: Re: Dispersion of light
Post by: chado on 2019-11-23, 17:00:20

Thanks for all!
I will try & show you my results later...