Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: Tedmurniey on 2025-05-15, 16:52:40

Title: Looking for help with strange dichroic material
Post by: Tedmurniey on 2025-05-15, 16:52:40
Hi guys!

How are you?

I am loooking for help with creating a particular dichroic glass.

I am not sure how to achieve it, as my material with its colours seems to be imitating light more towards the outside of the glass orbs rather than inside.
I also tried to make this with Volumetric Scattering, but sadly, it does not give the desired outcome, or I have no idea how to make a gradient with it :(

Any help would be really great!
Thank you
Ted
Title: Re: Looking for help with strange dichroic material
Post by: maru on 2025-05-15, 17:12:03
I'm not sure how the reference material "works" in real life but you can try:
1) Using a Gradient Ramp with Falloff to create this rainbowy effect (screenshot 1)
or
2) Actually giving your mesh some thickness (e.g. Shell modifier) and giving it a glass material with a crazy low dispersion value (screenshot 2)
Title: Re: Looking for help with strange dichroic material
Post by: romullus on 2025-05-15, 19:13:37
You can also try free ThinFilm plugin from Siger Studio: https://forum.corona-renderer.com/index.php?topic=7928.msg232995#msg232995
Title: Re: Looking for help with strange dichroic material
Post by: Tedmurniey on 2025-05-16, 12:00:46
Thank you very much Romullus and Maru! I will try both these solution!

Have a great Friday!
Title: Looking for further help with strange glass
Post by: Tedmurniey on 2025-05-29, 15:11:43
Hello dear Corona members,

I was recently helped by Maru and Romullus (thank you guys), but wanted to ask for further help.

I am attaching the screenshots of the glass I created compared to the glass that I want to achieve.

The main difference I see is in the way the color is distributed on the glass. In natural conditions, the color doesn’t form such distinct rings. The sphere seems to be covered with a film of more smoothly transitioning patches in rainbow hues. The color on the glass also doesn’t take on the surrounding colors so strongly—instead, it gives a tone to the reflections, or rather fades when exposed to intense light. Depending on the lighting, the saturation of individual colors also changes.

I tried to achieve this with the Thin Film plugin by Sigerstudio and with normal glass material with a high IOR + gradient ramp reflection gloss, but in both cases, the colour rings are created instead of simply transitioning the colour into reflections themselves.

I would be extremely grateful if anyone could achieve such an effect.

Thank you,
Ted
Title: Re: Looking for further help with strange glass
Post by: romullus on 2025-05-29, 15:58:22
It seems that your glass is reflecting much stronger than the reference, i would try to slightly lower IOR. Normally glass has 1.5-1.54 IOR, so default settings should work well, but maybe that's some special glass with lower index of refraction, who knows. Also your thin film hues are quite different, i think that means your thin film thickness is not quite right, try to adjust it as well. By the way, In the latest daily build, Corona physical material got built in thin film thickness, so if you're brave enough to use dailies, you can give it a try. I think that would excellent test for the new feature.

I'm merging your new thread with the old one - it's better to have discussions on the same topic in one place.
Title: Re: Looking for help with strange dichroic material
Post by: maru on 2025-06-16, 18:35:28
In scenes like this, lighting can greatly affect the appearance. In the photo reference there are strong reflections against a dark background.

Here is my attempt. I am not 100% sure, but I think the thin film colors vary across the surface of the lamps in the photo reference. I used a noise map to simulate this (as the thin film thickness texture using Corona 13's native thin film implementation).

Attaching an image and the scene itself (Max 2024).