BSSRDF Model

[Jacques]

It is hard/possible to implement it in VRAY? It is planned?

Thank you so much.

[natty]

are you talking about SubSurface Scattering or SSS.. yes vray can do this



Regards

[Jacques]

Yes i know, thanks

But i mean this method: (not glossy refraction-based vray current method)

http://graphics.ucsd.edu/~henrik/pap...ast_bssrdf.pdf
http://graphics.ucsd.edu/~henrik/pap...rdf/bssrdf.pdf

[Eugenio Jr.]

You have to take a look at Brazil's SSS, that seems to be the most right of all renderers.

I understand what you asking for Jacques and I wish it too...

Currently it's almost impossible to achieve a nice skin shader with vray (I never have seen any one).

Regard's

Jr.

[Jacques]

I have tested it and i don´t agree this.

However i have tested too the Finalrender Stage-1 new SSS algorithm and it seems to be closer to Henrik Wann Jensen model -sampling location irradiance-

Would it be possible that kind of algorithm implementation in VRAY?

Regards

[Eugenio Jr.]

Hi Jacques!

I mean that the Brazil's SSS was just the most right for the renderers right now (but it still is no so real like the Henrik's one), however I didn't know that the SSS in Final Render have changed. I have the service pack 2a and did some tests and it seems far different of the Henrik model, in fact, exactly the same as before. Unless this new algorithm come with FinalShaders.

But in some render tests I made with a character head that I created, Brazil's skin shader was the unique that really detect the differences in the distribution of the light in the thinner parts like ears, nose, etc. The other ones (Mental Ray, FinalRender and Vray) SSS distributes the light much equally over density and thinner parts. I must say that Vray's SSS is just a chaos compared to other in this subject.

I'm just too curious to see the test's you have made with the SSS of FinalRender. If you can to post any link or to send an e-mail to arkhanum@hotmail.com

Regards

Jr.

[Jacques]

Eugenio:

The sss change i'm talking about is from Stage-0 to Stage-1 -i think-

About Brazil's skin shader you're right but you can always tweak light distribution trough texture maps (deep, intensity--color, greyscale...)

I didn't keep those tests but i will post soon a WIP interior room showing this. It's made with VRay and a SSS layer from Finalrender Stage-1.

Regards.

[under1979]

Hi again! Sorry for the delay

Here is the test. The first one is pure 100% VRAY render. The second one is the same plus a FR SSS layer.

This picture was made by Sergio (my partner) and me. It belongs to a shortfilm we're making.






Regards,

Jorge.

Sorry my bad english

Ups! I forgot! I changed my nickname...

[suitaloon]

Are you talking about the marble starway?
(god damn good renderings by the way)

[under1979]

oh, thanks so much

Yes, there's only SSS in the marble starway.

Regards,

Jorge.

[percydaman]

I see no reason why vray couldn't do that. If youll email me the scene Id be happy to set it up for you..hehe



percy

[under1979]

Hehe, i don´t see the reason either

I know that VRAY is pretty capable to do this and much more. But i found (ONLY) FR hierachical SSS more flexible, faster and powerful than VRAY's.

http://graphics.ucsd.edu/~henrik/pap...ast_bssrdf.pdf

They use hierachical SSS, which is a new and much faster method of calculating SSS. Sort of like the interpolation in VRay, but much more accurate. I'd love to see this in VRay some day too.
_________________
Torgeir Holm
www.egz.com | VRay.info
Do you see anything that should be on VRay.info? Send an email to tips@vray.info

Regards,

Jorge.

[omness1]

Hi all,

I´m not sure why people can´t understand vray is the best GI render but his SSS is very very poor. Brazil R/S SSS have very good quality but Final Render SSS is more flexible (support channels and elements for example), fastest and have the best quality.

It´s very important for the Vray future the development of "fast bssdrf" (closer to Henrik), actually vray SSS are not ready for biggest producctions and I hope this changes soon (today this makes the difference).

[Geddart]

I'm sorry for going off topic but gosh!!! under1979, these are one of the best interior renderings i have ever seen!!! (...together with schloerb's Detention Images)

Have you posted these in the Image uploads forum? You really should.
I'm drooling to see more shots of your short movie! PLEASE!

[percydaman]

Heres a somewhat ad hoc test of using SSS to simulate marble in an interior scene. Please excuse the simple comparison scene, as I wanted to test the materials, not reproduce your excellent scene model.

After playing around with the sss material, I decided to slap the material on the entire scene and see how it came out.



While the left wall is completely blown out by the vraylights in the windows, Im sure that could have been fixed by excluding the wall from the vraylights. Whats nice is that there are some real nice looking marble in some locations.

Heres the scene rendered without the SSS material.



Im sure that if I fiddled around with it more, I could make it look ALOT better which brings me to the problem with SSS in vray. I truly believe you can reproduce just about any effect possible within other renderers, the problem lies in its approach. Its very hard to get the hang of, and since it renders so slow, its workflow is detrimental at best. Theres just too many different ways to adjust the effect. You can have 2 radically different settings, and have almost the exact same image, as it would seem that the settings can easily counteract themselves.


percy