mr mip_grayball for vray?

[sukistar]

hi,

i would like to integrate working with litshpere materials in vray.
right now, i have to turn to mental ray to render them using the mip_grayball shader, but i would like to
stay in vray.

i guess, mental mill could have been a way to construct the shader, but it's not available anymore.

any chance to get a map like mip_grayball for vray?


thanks

[vlado]

What is it supposed to do?

Best regards,
Vlado

[DanielBrew]

What is it supposed to do?

Have a look at this http://www.pixelcg.com/blog/?p=627
It demonstrates it quite well.

[sukistar]

here is a link to the original paper:
http://www.cs.utah.edu/npr/papers/LitSphere.pdf

it is actually the way zbrush, mudbox and sculptris can produce quite nice materials in realtime. not photoreal, but a great tool in the toolbox if you need to capture a certain look.
the material itself is just a square image of a lit sphere, which can be produced in all kinds of ways (even painted in photoshop).

i have a little vray scene set up where i can arrange lights and materials and render the sphere image, that i then use in a mip_grayball map, renders lightning fast, and you can easily combine it with displacement and normal maps from
zbrush.

zbrush itself has a tool to capture these materials.

[vlado]

here is a link to the original paper:
http://www.cs.utah.edu/npr/papers/LitSphere.pdf

Thanks, this is quite helpful. Actually a GLSL shader that does that would be something like 5 lines long, so I might at as well try to post one here a bit later, if you can get me some examples (see below).

the material itself is just a square image of a lit sphere, which can be produced in all kinds of ways (even painted in photoshop).

Can you post a few examples here along with images of what the output is supposed to look like?

Best regards,
Vlado

[vlado]

Nevermind, figured it out. Will post the GLSL shader in a moment.

Best regards,
Vlado

[vlado]

So here it is: http://pich.chaosgroup.com/vlado/vra.../litsphere.rar



Best regards,
Vlado

[sukistar]

wow, that was fast!

work perfect!

it is quite fast already, how much faster would this be as a plugin?

[vlado]

it is quite fast already, how much faster would this be as a plugin?

I don't know exactly... just faster I guess if it works ok for you for the time being, then all is good.

Best regards,
Vlado

[sukistar]

it does. thanks alot!

[flat]

I also wish the port to plug-in.

want to Mix with VRayBlendMtl or to combine with Opacity or Bump.
Or does VRayGLSLMtl support them?

[vlado]

Well, you can see the .frag file - you can modify it as you wish to do normal mapping or bump mapping or to support opacity, or I can do that later on if I have the time. It won't currently work inside a VRayBlendMtl material though.

In any case I'll make a note to implement a proper plugin material for this.

Best regards,
Vlado

[sukistar]

just use the VrayGLSLTex (in a standard or vraymaterial) instead of the glsl material, then you can do everything with it.
normally you would set the material to fully self-illuminated, but you can also mix real shading and the litsphere baked shading.

[vlado]

Yes, that would also be a good option

Best regards,
Vlado

[muoto]

Hmm...this is actually quite impressive...
I see nice ways to simulate env reflections, chrome matérials etc...
Woow...and just 5 lines of code master vlado !

edit : and put it in a extratex channel, then you can cas a nice env color on your scene...sweet !
edit : it won't work with vraysphere. maybe it needs a mesh ?