(Fixed,Fixed,Fixed) [HOU-2584,HOU-2585,HOU-2587] crash on rendering timeoffset packed alembics with subdivision

[ronald_a]

I am trying to render animated alembics which I time-offset (using abcframe intrinsic). This all works great, but when I enable subdivisions, vray writes a crashdump and houdini locks up. I can send a simplified scene to take a look at.

[chakarov]

Yes please, a simple scene will be very helpful.

[ronald_a]

chakarov mail sent.

[chakarov]

It's not the offseted alembic, mops/mops instancer are not supported, but it shouldn't crash anyway. I'll log it, and will add a request if it is possible to add support for mops as well.

[ronald_a]

Hi chakarov , thanks for looking into this. But mops is just manipulating the intrinsic attributes of the alembics, this should not need any seperate support, should it? Btw. this issue only seems to appear in new vfh versions (I just tested today's build) but not in older versions using 5.0 core (in our case V-Ray for Houdini number:12947 hash:a138195 from 08 Apr 2021 01:55 (build number:12947)
V-Ray Core 5.00.50 [fcc821e3] from 31 Mar 2021)

[ronald_a]

chakarov I need to add that offsetting alembic timing through the intrinsic abcframe attribute does seem to have issues when creating vrscenes (not picking up the correct frame). it has no issues while in gui mode (even if the houdini viewport does not show the correct frames of the alembics which it does pretty often) but when creating vrscenes (through hython) it appears, that it is not picking up the correct frame of the alembic. this is also true for core 5.0 versions.

[glacierise]

I've done a lot of that recently with 4.30 and it was working, have you tested there or in 5 only?

[ronald_a]

Yeah, only vray 5 as we have switched (we did have issues with the vray 4 builds for houdini 18.5.x). I also was under the impression that this worked before. I should probably put together a little sample scene for this to get resolved. have you not switched to 5 yet?

[chakarov]

I've reproduced the problem, seems that MOPS crashes V-Ray in Houdini python3, and crash with subdivision in Houdini python2 only in V-Ray 5. In V-Ray 4.3 everything is fine.

[ronald_a]

chakarov great. Can it be fixed (or is this a mops issue)? Also could you reproduce the issues I have with vray not picking up the correct frame out of the alembic? If not, I can create an example scene that should illustrate the problem.

[chakarov]

Example file is OK.

[ronald_a]

chakarov I will send a file asap. In the meanwhile I dug a little deeper into the crash issue and it seems that it is not a mops issue but an alembic file issue. the mesh inside the abc has a couple of prim groups, if I delete them (and rewrite the abc), the crashes go away. hope this gives you a lead to what is wrong.

[chakarov]

Mops in python 3 V-ray is fixed in todays nightly. Crash when subdividing mops is in code review, but you could use "open subdiv" instead.

[ronald_a]

Hi chakarov , that great news!


I also just sent you an example via mail which shows the problem with the wrong alembic frame.

[chakarov]

Hi ronald_devries , I've received the mail and reproduced the problem. It is reported now.