Caustics with new VRay Materials

[L_ARSENAL]

Hello guys,

I've got some issues with Caustics and new Vray Materials, and Vray Express Materials.
My scene is standart, Vray plane, one Rectangular light, and a diamond.
All images are rendered with same settings.
My caustics settings are :


For the first image, i used vray old standard material, and setup for being a diamond material.
You can see Caustics under the diamond.


Second is rendered with new VrayMtl, no caustics under the diamond.


And the third is rendered with Vray Express Diamond setup, little caustics under Diamond, but just white light.


I made some renders with juste a ball, and basic glass tinted material, with old material i have some coloured caustics, and no caustics with the new one.
I tryed Caustics in reference of this video http://www.youtube.com/watch?v=F2c8cSArXnM but it's Vray for Max.
Also i just can't make the same sharp caustics as he did.

Maybe my settings are not good with the new materials, and to be honnest, i'm not a Vray professional yet

Also i didn't find the way to add Bump and Displacement to the new VrayMtl...
It is mentionned in the help files (http://help.chaosgroup.com/vray/help...aymaterial.htm) that it's possible to add them.

Does anyone had a solution ?

Best regards from France !

(Sorry if my english looks like french...)

[fpedrogo]

Hi
To give you a quick answer for the bump and displacement on the new V-Ray Material. Right now there is no way to add bump map or displacement to that material. However we have the same material as a layer for the Standard material. So the workflow will be to start with the standard material, delete the diffuse layer and add a BRDF layer. In this way you will have the option of the new V-Ray materials and the maps are from the standard material and you will be able to use bump and displacement.
In term of the caustics I will have to make some test. The coloration on the caustics is due the dispersion option and it should be visible in the express diamond material and in the new V-Ray Material. Is there any way that you could share your scene with me?

I made the V-Ray express materials using the above mentioned workflow, a standard material with a BRDF layer.

[L_ARSENAL]

Hello,
I've see the new layer for standard materials, i didn't know it was the same as new VrayMtl, Thx.
The new materials are very fast than old standard, and this is cool !

For the caustics issue, here : http://www.3huit.com/temp/learn_caustics.zip you can find my scene, i only save my file, i don't know if the materials are in...
Tell me if not, i will export the materials and uplord on my web site.
In the file you will find a diamond and a ball, each for differents tests.
I've made other tests and the problem still there, i still don't know how to make good caustics with the new materials...

Thx for helping

[Micha]

Hi,

I'm curious - what means "new materials" and what can be expected?

[L_ARSENAL]

New Materials mean the new VrayMtl >> http://help.chaosgroup.com/vray/help...aymaterial.htm
better, stronger, faster it's a remplacement material for the "old standard material", all layers in one.

[fpedrogo]

Hi Micha

I'm curious - what means "new materials" and what can be expected?

I haven't made any serious test, but I also have the impression that the BRDF material is faster than the standard materials , specially with glossiness metals and transparencies.

[fpedrogo]

Hi L_ARSENAL
Seem that the BDRF material do not recognize dispersion caustics. I'll make a bug ticket about this issue.
Thank you.

[Micha]

Thank you Guys, looks like I need to start a test.

[L_ARSENAL]

Glad to help the community ! Hope it will be corrected, the new BRDF material is really faster than the standard we used before !!

[Micha]

I rendered a complete train interior with the override material method (4m:35s @ 32cores) and the speed difference was 1s. I setup a satin white material. Some small areas was a little bit better looking with the new material. So far no big difference, I will test more.

[Micha]

I took an interior scene and render it with a froozen glass material, than the same with a BRDF material. I got a doubled render time and a totally different look. Looks like the refraction/reflection goes an other way.

[L_ARSENAL]

The BRDF Material looks to work othrewise, i agree with you Micha.
I don't do interior tests, but only close up elements... BRDF looks faster but the quality looks is bit worth on reflection and refraction, maybe due to the problem that fpedrgo mentionned before.
Wait n' see for an update on this material