Alembic based vray cutter

[9k_JHT]

As promised, the animation is posted below. All but one issue seems to be gone! There is a noticeable flicker right at the end of the alembic animation sequence. Along with the video output I posted two frames (before and after flicker). This is a GI issue potentially and will start another render today with GI turned off to see if the issue is resolved. Even if it is a GI issue I'd presume the clipper operation is the instigator as the flicker happens right at the last frame of the alembic animation. Please advise on this! If I can get this working without any GI I will go for that because of project deadlines, but if the Chaosgroup team can look into why this is happening or offer suggestions to avoid it from happening I'd appreciate it.



VIDEO-

Both Frames together:


Frame:103 pre-flicker:


Frame:104 post-flicker:



Thank you!

[9k_JHT]

Another update after putting together the animation I had going over the weekend without any GI. Still getting the flickering after the alembic clipper object plays through. A good thing to mention is I'm having the alembic hold on last frame. Considering the flicker, light/shadow shift happens at completion of the alembic play through, I'd assume the hold alembic option isn't jiving well with VRay. I'm going to rebuild the clipper without using an alembic now (since Autodesk cleared things up with their flow object path bug).

I'll report if anything changes. In the mean time, if anyone here has any suggestions I'd appreciate it. This project has been problematic, but I'm excited to see it almost complete.

Thanks,
Clayton

[9k_JHT]

Hey all. So again, the clipper is clipping the appropriate amount of geometry now with alembic. I still am having a whole slew of different issues here that I don't really know where to start on. Please advise. If you'd like me to create another thread in "problems" section let me know. I'm going to render this again but without the clipper completely.


So far these are the render variations I've tried-

No GI

No GI - No Camera motion blur

No GI - No Camera motion blur - No alembic for clipper (used another solution provided by AD).


I don't really know what else to do here. This isn't the next ILM feature film I'm working on, but a really simple scene and I've tried to figure out what's going on through process of elimination on my end. Any further help would be appreciated. I've made a video (below) clearly illustrating the issues. Thanks.

[stezza]

Has similar issue to solve it I rendered out all objects separately with Vray object prop node to cut out each object and this stopped my flicker. I would get random flicker just on one frame, previous and next frames were fine I couldn't work out where it came from.
It didn't matter if it had GI or not. I had alembic in the scene with a VRay cutter but these two did not intersect at all.

[9k_JHT]

Has similar issue to solve it I rendered out all objects separately with Vray object prop node to cut out each object and this stopped my flicker. I would get random flicker just on one frame, previous and next frames were fine I couldn't work out where it came from.
It didn't matter if it had GI or not. I had alembic in the scene with a VRay cutter but these two did not intersect at all.

That doesn't sound too hopeful for my case. I'm not going to butcher up my animation to make it "work". Thank you for the input though! It does help to know that others have had this similar issue as well. Hopefully the devs can come up with an explanation or a fix or something. Right now the last test was void of any alembic as well.

[yavor.rubenov]

Hello,

We are still trying to find the reason for the other issues you are having - the flicker and etc..
As soon as we find something - we'll write back. Sorry for the inconvenience.

Best regards,
Yavor

[9k_JHT]

Hello,

We are still trying to find the reason for the other issues you are having - the flicker and etc..
As soon as we find something - we'll write back. Sorry for the inconvenience.

Best regards,
Yavor

There are thousands of variables your dev team needs to manage. This stuff is very complex on the development end of things and I appreciate that. Just let me know when you get to the bottom of it or if you need any further information from me or when/if you can provide a timeline to solution so I can report to my superiors about this project.

If I need to hack something together I will, but I'd rather avoid doing so. Thank you again for all the help.

Best,
Clayton

[9k_JHT]

I know the V-Ray devs are already on the case, but I wanted to add more information to the discussion. After removing the vray clipper (not even alembic clipper, but a true non-cached mesh which was animated by a deformer in Maya) all the issues in my previous video went away (including the triplanar projection issue).

Below is the animation without any clipper-

It seems the clipper in general is the cause of these problems, not just having an alembic clipper object. Good luck and let me know if you need anything from me regarding these issue.

Best,
Clayton

[yolov]

Glad to know there's a workaround. We'll keep working on this and hopefully we'll find a way to fix it.
Apologies again for any inconveniences caused.

[9k_JHT]

Glad to know there's a workaround. We'll keep working on this and hopefully we'll find a way to fix it.
Apologies again for any inconveniences caused.

No work around. Just completely removing the clipper makes the issues go away (but I need the clipper for this project). I look forward to any updates on this.

[yolov]

Sorry for the misunderstanding. We're still looking into this.

[yolov]

So far, I suspect the flicker comes from shadows being cast in one frame but not in the next one ( I suspect the outer shell that being cut - grp_outerShell_DC_01_outerShell_DC_01_bakedToWorld 1 but again - this is only a suspicion for now). We'll try to get to the bottom of this.
Again, apologies for the misunderstanding.

[yolov]

I did a full animation test by just disabling "cast shadows" in the vray object properties that were already assigned to grp_outerShell_DC_01_outerShell_DC_01_bakedToWorld
You could see if you can use that as a workaround until we manage to fix the problem.
There's still some visible flickering - but it's from the noise, because I used lowered quality settings to manage to render the whole sequence in less time to test the workaround.
The side effect is that the copper coils became a bit darker than before.

https://youtu.be/9KsYHpJBapA

[9k_JHT]

I did a full animation test by just disabling "cast shadows" in the vray object properties that were already assigned to grp_outerShell_DC_01_outerShell_DC_01_bakedToWorld
You could see if you can use that as a workaround until we manage to fix the problem.
There's still some visible flickering - but it's from the noise, because I used lowered quality settings to manage to render the whole sequence in less time to test the workaround.
The side effect is that the copper coils became a bit darker than before.

https://youtu.be/9KsYHpJBapA

Fantastic! I thought I already gave that a shot, but I guess I was mistaken! Makes sense to get rid of the shadows completely. I'll start a production render over the weekend (which probably will bleed into the following week) and let you know how it worked out! Sure it'll be fine.

Thanks again for taking the time to look at this! Great support as always.

Best,
Clayton

[9k_JHT]

I did a full animation test by just disabling "cast shadows" in the vray object properties that were already assigned to grp_outerShell_DC_01_outerShell_DC_01_bakedToWorld
You could see if you can use that as a workaround until we manage to fix the problem.
There's still some visible flickering - but it's from the noise, because I used lowered quality settings to manage to render the whole sequence in less time to test the workaround.
The side effect is that the copper coils became a bit darker than before.

https://youtu.be/9KsYHpJBapA

I wasn't crazy. I tic'd off "Cast Shadows" in My "shell_VOP" as well and still got errors using the non-alembic clipper. Can you confirm this is what you were referring to? If so something else is screwy here because I already tried turning off cast shadows during my troubleshooting.