VrayClipper issues.

[ricoholmes]

Note: this issue has now been fully resolved
Yolov - ask for a pay-rise !

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Hiya fabulous folks

Running into clipper issues again I'm afraid. This one is CPU/Meshmode based, and on VRayNext Beta2 so I thought it deserved a new thread.






Honestly. Sad Rico here too, because surely this should just work ?


I've attached a simple Maya scene hoping can point out my mistake. You'd be a sanity saver!

/RH

[shaio]

Hi,
I've logged the issue to our bug tracker (ticked VMAYA-8073). We'll let you know as soon as it is fixed. Thank you for your feedback.

[ricoholmes]

Thank you Shaio.
Out of pure curiosity - is this a Maya only issue or does it happen in other DCC's ? Maya's lack of reliable Booleans makes clipper a potential godsend, but, well, it's always had issues of its own...

[ricoholmes]

Any news on this? Seeing a related issue in a production shot now

[ricoholmes]

Again (and sorry to be a PITA.. this is causing us serious delays as we've counted on it being functional for a bid on a series of jobs)

Sample scene for another scenario attached.
It's been cut back, simplified and abstracted just for the purpose of troubleshooting.

ClipperTroubleshooting.zip

[shaio]

We're working on the issue and will update the thread as soon as we have some new information. Thank you for the new scene. We'll look in to it and check if there are new issues there.

[ricoholmes]

Thank you Ivan. If there's anything else I can do or supply to help, then I'd be happy to of course.

[yavor.rubenov]

Hello,

I've so far examined the first scene and will try to explain what is the problem. (Sorry for the simple Paint drawings).

First some very simple case:

The black box is some geometry, the green one is a mesh clipper in intersection mode. The result is in yellow.
If we add another geometry like this:

The blue box is some other geometry. We exclude it from the clipper (or only include the black box - it's the same). By excluding the blue box we are saying that it's full volume should not be clipped. So here the result is the same as the first case - the yellow area.

Now the complicated case:

Here the black and the blue box intersect. So now the grey volume is inside both the black included box and the blue excluded box.

The regular Boolean operation would do the intersection between the black box and the clipper before rendering and we won't have a problem.

The clipper on the other hand works during rendering and sees both boxes. For the clipper the grey volume is both in the included and the excluded volume and there is no easy way to decide should we shade it or not.

In your scene the black box is the water block, the glass container is the blue one. Things here are even more complicated because for proper liquid rendering you would need the liquid to intersect the glass..

I'm not sure we can reliably solve this case without breaking other ones - I'll try to find some solution..

Sorry for the inconvenience.

Best regards,
Yavor

[ricoholmes]

Hi Yavor,

Thank you SO much for looking into this properly. I appreciate and sypathize with you for the problems you’re seeing here. The very last thing i want is to be awkward.

The technology is potentially phenominal in its usefulness of course.

In this case it’s the difference between being able to animate liquids (with the fabulous VRay water for displacment) through valve systems without having to resort to messy and time consuming fluid simulation. We have a large range of projects that are only really viable with the clipper as a solution. The initial tests looked oustanding, with which we won the bid. It wasn’t until we hit this problem with mutliple containers in early production we realized we were in real trouble if we can’t use clipper reliably. We’re frankly in a bit of a panic situation now, though I’m sure you don’t deserve that on your conscience.

Again, I really do hope you’re able to find some clever solution, given these real world problems. If there’s anything I can do to aid the process then feel free to PM me on fb messenger or email. I’d be more than happy tp help in any way of course.

Sincerely,
/Rico

[ricoholmes]

Hi again Yavor,

It's been troubling me all night and on the commute to the studio, trying to find a viable alternative solution ( I really do recognize the issues you're facing ). I might be banging my head not seeing the obvious, as I keep returning to a mesh boolean approach rather than rendertime boolean approach and I just can't get it to work. So I thought I'd do a rudimentary illustration to put out there and see if it fires a more creative mind/approach

It also illustrates why clipper is fabulous when it works



So you see where things are catching me out at least. Hopefully I've missed an obvious answer and will kick myself.

/Rico

[yolov]

Hi Rico,

This issue has just been fixed and the fix will be included in the upcoming Beta 3 release for V-Ray for Maya.

[ricoholmes]

Thank you Yolov - I can confirm it's working superbly now. You are a hero

[yolov]

Thank you Yolov - I can confirm it's working superbly now. You are a hero

Credit goes to our awesome developers!