Dispersion shader

[cecofuli]

As in the title, a dispersion features for realistic diamond and glasses. Thanks!

[cecofuli]

This was the good old fake method with VRay.

[APrather]

It was asked before http://forum.corona-renderer.com/index.php/topic,311.0.html  B

BTW Nice Vray dispersion you got there.

[maru]

here is my fake dispersion done in Corona :]

http://forum.corona-renderer.com/index.php?action=dlattach;topic=223.0;attach=1887;image

[cecofuli]

Maru... how did  you do that? It look not bad at all.

[cecofuli]

This is my Corona render. The diamond looks looks like a normal glass :/

[maru]

Basically it's done like your vray fake. Here are the instructions. It's dirty and ugly but more or less does its job.

[cecofuli]

Ok I tried, but the diamond becomes dark with this shader.
I think we have to wait Ondra...  =(

[maru]

Yeah, the colours should mix in a different way. And something is wrong with the blend material.

[cecofuli]

We have to wait a new CoronaBlendMtl ;-)  and/or dispersion option in the CoronaMtl.

[Chakib]

i hope we can see it soon cause the glass in corona is just amazing even without caustics...

[lacilaci]

Well dispersion was mentioned before. If I remember correctly, Ondra said, it will be done. But right now it's not a top priority to do... Which is understandable i think.

[cecofuli]

Yes, but, for example, with VRay was possible create a "fake dispersion". And, for some project, it's enough.
I have to use VRay for our next project cause Corona doesn't support dispersion. It's important when you are working with jewelry ;-)

[cecofuli]

UP =)

[borisquezadaa]

Playing with diamonds...

i just came up with this aproach to fake dispersion:

Diamond has a ior of 2.418 and a dispersion of 0.044 (wikipedia) XD.

So i created 3 materials one with IOR 2.374, one with IOR 2.418 and one with IOR 2.462

Apply first material (ior 2.374) and render, saving only the red channel (in post tab).
Then apply second material (ior 2.418) and render only saving green channel.
Finally apply third material (IOR 2.462) and render only saving blue channel.

Load that 3 images in photoshop seting layer as addittive and get nice FAKE dispersion.

Pretty nice trick. And Eureka moment.