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Point cloud sss with hdr illumination?

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Hi to all I wonder how to use the mario's sss shader with proper per shading hdr illumination.And another question about using the shader in renderman is it possible to use the bake3d function in prman12 or dumpgrid in older versions with the mantra includes and a custom sl shader.


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Hi and welcome, Sabotage.

Hope you enjoy your stay at odforce...

Are you referring to IBL (Image based lighting) from an HDR image? Mario's shader responds to conventional 3d lights. If you have a method for generating a light-dome from and HDR Image - there is (or was) a Houdini plugin for HDRShop (I haven't looked in a while) - it should work fine. It doesn't directly handle an HDR reflection environment AFAIK. Perhaps Mario has thought of this more carefully - Mario?

I'm not terribly sure I understand your prman question, sorry...

Take care,


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About the IBL I don't like the dome way it is oldfashion and only used with depth based sss but here with point cloud we can directly call GI

and using one bounce light and ambient occlusion it is possible to make IBL with sss per shading

My prman question is there a way to rewrite this shader for renderman


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Hi sabotage,

The multiple scattering component can be made to work with GI (though it will slow things down conciderably of course). Just replace all calls to pcIllum() with pcIrrad(). The pcIrrad() function is included in the code (in the AV_pcloud.h module) but I never got around to testing it. The single scattering component however, is not an algorithm that can play nice with GI. But you typically would want to tie single scattering to your key light(s), so that shouldn't be a problem.

As an aside, I guess I'm old fashioned since I use light domes for all sorts of effects on a regular basis ;)

As far as an RSL translation... never got around to doing it since we're now using Mantra for the most part. But I'm willing to help out with the algorithm if you intend to do one yourself... if you don't mind sharing your results with everyone, that is :)


P.S: I don't know which version of my sss stuff you picked up, but you should be using the one posted here.

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Thank you Mario for the great feedback, I will share evry step I made with the translation of the code.My idea is that renderman suits better with point cloud bssrdf.I would like to implement 'hery's functions.

I will need a little feedback from you because some parts of the proccess are very confusing.


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