Displacement > True crash blender in this file
Closed, ResolvedPublic

Description

System Information
Kubuntu Linux 14.04, GTX 960

Blender Version
Broken: 2.78 from buildbot ( 96f28f9 )

Short description of error
This problem is related to this 'asphalt.blend' test file from this user:
https://blenderartists.org/forum/showthread.php?396697-Cycles-new-microdisplacement-build-and-testing&p=3097111&viewfull=1#post3097111


It seems that 'Ffrima' does not reported yet, so I do the report.
Blender crash when you change Displacement to True

Exact steps for others to reproduce the error
Open 'asphalt.blend' file and change Bump to True in Displacement.

YAFU (YAFU) updated the task description. (Show Details)Sep 11 2016, 5:00 PM
Sergey Sharybin (sergey) triaged this task as Confirmed priority.Sep 12 2016, 5:21 PM

Settings used for musgrave texture are quite insane, they are causing some floating point overflows, resulting in really nasty (inf, nan, fltmax) positions for vertices. This confuses BVH builder a lot.

Not sure what would be a real solution here. On the one hand BVH could become more robust perhaps (binning of such a number wouldn't be fun tho) or maybe we should clamp displacement, or maybe we should clamp node settings..

@Brecht Van Lommel (brecht), @Mai Lavelle (maiself) any ideas here?

I don't think its good that the node produces such results, but maybe this could be fixed by skipping displacement of vertices when the displacement is inf/nan?

Definitely reject non-finite displacements. Fixing texture node(s) would be nice too, though I think we have to be robust to such values coming from the node system.