V-Ray Alsurface VS other SSS methods

Some SSS render tests just fresh out from my render farm! Comparing all the SSS methods we now have in V-Ray.

N.B: The effect is exagerated just to show how the SSS behaves and not mean to be photoreal. I also didn't spent too much time trying to match each shader cause the other ones are just too long to adjust and I think it's just obvious that the best (at least for skin) is the Alshader. The translucency in the regular V-Ray material is so much faster that it could be useful too.

The Alsurface shader (originally developped for Arnold by Anders Langlands) that Vlado just ported for V-Ray is available on Github:

This shader is not too long to render, the effect of the light passing through is the most realistic and the colors of each part is easy to control, you can adjust one color without screwing up the other colors.

V-Rays SSS2 was so difficult to control when you wanted to add some more red in the ears, the rest of the skin started to get some green (or the complimentary color).

The Alsurface render time is approximatively equal to that of SSS2.

The skin material was faster to render but also difficult to control the color and not so realistic.

The scatter volume is maybe the most realistic but I rendred it with the samping at zero cause it was just too slow to render, probably more than a hour to get clean result. Also I the transparency is too direct on that one, I could never get it to blur like the refraction glossiness. Maybe there's a way but it's so long to render to have didn't have time to test this shader more than this.

The translucency in the regular v-ray material is another method to get sss and it is very fast to render. That's the one that I used the most in my jobs cause it works great for food like cereal and such. But on a human's skin it doesn't look realistic unless you use it in a very subtle way.

But now with the alsurface, you can be sure I won't use any other shader in V-Ray for SSS (except maybe the translucency when I need to render very fast).

For more on this shader, also see those links:



Music: Erik Satie: Gymnopedie No 2 by Kevin MacLeod: creativecommons.org/licenses/by/3.0/