Its possible to implement SSS Effects with brick maps like renderman does but in mantra?

The point cloud method is very limited in animated geometry, and dont work very well in conjunction with bump maps.

Thanks.

It's not the smoothest workflow but you might want to look into using a surface shader to dump the point-cloud for you.

http://www.sidefx.com/docs/houdini9.5/vex/functions/pcwrite [sidefx.com]

If you do this for every frame, you can represent displacements. Or you can look at the Axis SSS VOP on this forum that uses raytracing to calculate SSS for you.

I added an important note to the bottom of this Help page too: http://www.sidefx.com/docs/houdini9.5/nodes/vop/multiSSS [sidefx.com]

hey jason

thx for the tip in the help file
jason

Thanks jason, the pcwrite function is a great complement for the sss shader with displacements.

Thank you very much.

Please correct me if I'm wrong but isnt't point cloud method quite convenient for all kinds of animated effects with constant topology objects?

While using pcwrite (and mantra told not to cull micropolys) to generate pointcloud from micropolygons, we get samples always in the same positions (moving with geometry points) which avoid resampling problems like global illumination flickering.

Complete weirdo or just a little :?:

One important area where Micropolygon rendering differs from Raytracing is that Micropoly will shade every vertex in a model, even if the model fits into only 1 pixel. Of course, conversely: if a single poly (micropoly) spans over more than one pixel, the micropoly is diced and the new vertices are shaded too. With raytracing this is different, with a fixed number of samples being shot through each pixel.

If you pcwrite from a micropolygon render, you'll see that *at least* every point on the original geometry (depending on Shading Quality and pixel coverage). You should be able to get pretty stable (non-flickering) SSS from that, yeah.

If you pcwrite from a raytrace render, you'll see the samples are not associated with the point positions on your geometry, and you might easily changing/flickering point clouds, true.

I was thinking micropoly, but perhaps it is possible to pcwrite from micropoly and use pc in raytrace
:twisted: