Author Topic: Dispersion shader  (Read 20976 times)

2013-07-01, 11:44:13

cecofuli

  • Active Users
  • **
  • Posts: 1494
    • View Profile
As in the title, a dispersion features for realistic diamond and glasses. Thanks!

« Last Edit: 2013-07-01, 15:42:48 by cecofuli »

2013-07-01, 16:12:22
Reply #1

cecofuli

  • Active Users
  • **
  • Posts: 1494
    • View Profile
This was the good old fake method with VRay.




2013-07-01, 16:53:00
Reply #2

APrather

  • Active Users
  • **
  • Posts: 18
    • View Profile
It was asked before http://corona-renderer.com/forum/index.php/topic,311.0.html  B

BTW Nice Vray dispersion you got there.


2013-07-01, 17:45:20
Reply #4

cecofuli

  • Active Users
  • **
  • Posts: 1494
    • View Profile
Maru... how did  you do that? It look not bad at all.

2013-07-01, 17:52:15
Reply #5

cecofuli

  • Active Users
  • **
  • Posts: 1494
    • View Profile
This is my Corona render. The diamond looks looks like a normal glass :/

« Last Edit: 2013-07-01, 17:53:58 by cecofuli »

2013-07-01, 18:18:11
Reply #6

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 9456
  • Marcin
    • View Profile
Basically it's done like your vray fake. Here are the instructions. It's dirty and ugly but more or less does its job.

2013-07-01, 18:41:13
Reply #7

cecofuli

  • Active Users
  • **
  • Posts: 1494
    • View Profile
Ok I tried, but the diamond becomes dark with this shader.
I think we have to wait Ondra...  =(

2013-07-01, 19:01:56
Reply #8

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 9456
  • Marcin
    • View Profile
Yeah, the colours should mix in a different way. And something is wrong with the blend material.

2013-07-01, 19:15:21
Reply #9

cecofuli

  • Active Users
  • **
  • Posts: 1494
    • View Profile
We have to wait a new CoronaBlendMtl ;-)  and/or dispersion option in the CoronaMtl.

2013-07-04, 02:26:51
Reply #10

Chakib

  • Active Users
  • **
  • Posts: 787
  • Corona Omnomnomer !
    • View Profile
i hope we can see it soon cause the glass in corona is just amazing even without caustics...

2013-07-04, 13:49:11
Reply #11

lacilaci

  • Active Users
  • **
  • Posts: 757
    • View Profile
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.

2013-07-04, 14:17:07
Reply #12

cecofuli

  • Active Users
  • **
  • Posts: 1494
    • View Profile
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 ;-)

2013-08-07, 18:51:26
Reply #13

cecofuli

  • Active Users
  • **
  • Posts: 1494
    • View Profile
UP =)

2014-03-18, 01:59:18
Reply #14

borisquezadaa

  • Active Users
  • **
  • Posts: 615
    • View Profile
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.
What i do with Corona My Corona post of random stuff rendering
WARNING: English.dll still loading...

2014-03-24, 12:19:26
Reply #15

Nekrobul

  • Primary Certified Instructor
  • Active Users
  • ***
  • Posts: 1028
    • View Profile
Well i have tried one method too similar to v-ray fake method but i little more dificult.

I used 3 blend materials with 4 different materials inside and 3 fallof maps to mixthem together.

in close up it still looks un realistik but from the distance gives needed effect.
---------------------------------------------------------------
https://www.blackbellstudio.com/
https://www.behance.net/blackbell3d
CEO at "Blackbell Studio"

2014-03-24, 13:07:11
Reply #16

agentdark45

  • Active Users
  • **
  • Posts: 492
    • View Profile
Hi Nekrobul would you mind uploading your material for testing? I've currently doing a project with some crystal wall sconces and can't quite nail the look (currently using a regular glass material with caustics ticked, ior 2.0 for both ref+refract).

Many thanks

Vray who?

2014-03-24, 13:12:34
Reply #17

Nekrobul

  • Primary Certified Instructor
  • Active Users
  • ***
  • Posts: 1028
    • View Profile
Only in couple of hours or later, need to do some urgent work now)
---------------------------------------------------------------
https://www.blackbellstudio.com/
https://www.behance.net/blackbell3d
CEO at "Blackbell Studio"

2014-03-24, 14:22:45
Reply #18

agentdark45

  • Active Users
  • **
  • Posts: 492
    • View Profile
Thanks man
Vray who?

2014-03-24, 15:19:14
Reply #19

borisquezadaa

  • Active Users
  • **
  • Posts: 615
    • View Profile
You may try with this way of doing...
http://corona-renderer.com/forum/index.php/topic,3093.0.html

Only thing is to change refraction (For a SiO type glass...)]

658nm=1.5418
510nm=1.54812
440nm=1.55339
What i do with Corona My Corona post of random stuff rendering
WARNING: English.dll still loading...

2015-03-10, 19:28:41
Reply #20

XRef

  • Active Users
  • **
  • Posts: 12
    • View Profile
Is there any new info on rendering diamonds? I made an attempt similar to cecofuli's render...


2015-03-10, 19:36:06
Reply #21

cecofuli

  • Active Users
  • **
  • Posts: 1494
    • View Profile
We need to wait dispersion. I hope soon (Ondra? ^__^ )

2015-05-29, 12:41:24
Reply #22

tomislavn

  • Active Users
  • **
  • Posts: 695
  • Lightbringer
    • View Profile
    • My 3docean Portolio
Any news on dispersion option Ondra? :)
My 3d stock portfolio - http://3docean.net/user/tomislavn

2015-06-05, 21:57:19
Reply #23

mitviz

  • Active Users
  • **
  • Posts: 482
  • Architectural/Product Modeling and Rendering
    • View Profile
    • MITVIZ
bump for this request!i need it so badly
Mitviz
Professional Modeling and Rendering Solutions
Intel core i7-5960x cpu @3 GHz, GeForce GTX 970

2016-04-18, 11:30:40
Reply #24

Tanakov

  • Active Users
  • **
  • Posts: 797
  • Corona is faster than diarrhea
    • View Profile
    • https://www.behance.net/Gringott
Bumpy :)
Corona since 2014.06.02
https://www.behance.net/Gringott

2016-04-18, 14:03:17
Reply #25

maru

  • Corona Team
  • Active Users
  • ****
  • Posts: 9456
  • Marcin
    • View Profile