standard_surface SSS doesn't use bump maps?

[Anonymous]

I'm trying to replicate the appearance of alSurface from Arnold 4.x on Arnold 5, and I'm having some trouble doing this with the new standard_surface SSS modes.

Neither seem to take into consideration any bump or normal maps applied to the material. The diffuse channel certainly does, and if the SSS weight is less than 1.0, then I can see that effect accordingly- but the SSS itself does not seem to consider any bump maps or normal maps at all, which is pretty obvious when the SSS weight is near or at 1.0.

Is this supposed to happen? alShaders seemed to take the bump maps into consideration. I can't really use autobump in this case because I've got a bunch of normal maps that I'd like to affect the SSS if possible. Is this just not possible in Arnold anymore?

[lee_griggs]

If you lower the SSS Weight below 1 you should see something.

[alan.kingFCDLA · Accepted solution]

There is a render option to allow SSS to "see" the surface's autobump called "sss_use_autobump". You could try toggling this to see if it helps.

This option is disabled by default because of the additional render cost it incurs and the fact that autobump is imperceptible in SSS if the scattering radius is relatively large.