Pasta with VRay fastSSS2 WIP

[jstrob]

I did some pasta using the VRay fastSSS2 with raytrace.

I wonder why I am getting some darkness in the corners. This is in Simple mode for the single scatter. And when I try Raytrace (refractive) mode, everything gets very dark.

[vlado]

This is in Simple mode for the single scatter. And when I try Raytrace (refractive) mode, everything gets very dark.

Try "raytraced (solid)". I can reproduce the issue with the refractive one - looking into it now.

Best regards,
Vlado

[cheerioboy]

neat renders

makes me hungry...

[jstrob]

Thank you Brendan, that's the goal!

And thank you for looking into it Vlado. When I try Raytrace (solid) I get the exact same result but just longer to render. See here:


And with Raytrace (refractive):

[vlado]

Ok, will try to reproduce the darkening here too. It will help if you can send me a scene with just one macaroni piece to vlado@chaosgroup.com

Best regards,
Vlado

[jstrob]

I just sent a scene to you

UPDATE: oups, it was stuck in my sending box. Now it is sent.

[jstrob]

I am reading the doc for fastSSS2. https://docs.chaosgroup.com/display/VRAY3/VRayFastSSS2

I found some mistakes I think.

First: Geometry based sampling: I don't see this parameter in the shader but it is the first you explain in the doc.

And then the parameters in the doc are not in the same order as they appear in the shader.

Also the parameter "Prepass rate" is not in bold and it's inside the paragraph for Prepass ID instead of having its own paragraph.

Finally, there is no multiple scattering section. I would like to read an explanation of the 3 different mode for multiple scattering.

[jstrob]

I am now trying to put some filling in those mezzelune pasta. I put a dark ball inside of it, but it just look like it's a bright object instead of a dark one. It seems we can't see something dark in transparency through the FastSSS2 shader. I wonder how I could reproduce this.


see this photo reference I am trying to reproduce:






Where could I find this head that we see in the help file? Is it possible to download it somewhere?

[Raven]

Ajax scan is here

http://www.jotero.com/objekte/Ajax_J...om_3ds_obj.rar

[jstrob]

Ok I didn't know it was Ajax! thanks I will try to reproduce it to see what's going on with this shader.

[vlado]

It might also be worth to try with the translucency in the VRayMtl material.

Best regards,
Vlado

[Morbid Angel]

I apologize if this has been said as I didn't read through the whole post. It seems to be that where the dark areas appear in the sss, it should be brighter there? Now this does not feel natural to me...

[jstrob]

It might also be worth to try with the translucency in the VRayMtl material.

Best regards,
Vlado

I will try it too.

[jstrob]

I apologize if this has been said as I didn't read through the whole post. It seems to be that where the dark areas appear in the sss, it should be brighter there? Now this does not feel natural to me...

Exactly! the pointy parts should be brighter. I will try to expreriment at different scales to see if nothing improve.

[jstrob]

Here are a few test I made with the ajax head.

Object-based illumination map-Raytraced(solid)-scale001, 010 and 100


Prepass-based illumination map-Raytraced(solid)-scale001, 010 and 100


Raytraced-Raytraced (solid)-scale001, 010 and 100


It seems a bit different from what we see in the vray3 doc. The reflection is now cut by the occluding pasrts of the object which I think is more realistic.

here the ones from the doc: single scatter was Raytraced solid (but multiple scatter was not specified).