Hello,
For a upcoming project i am working on a simple ship sim. All works wonderful but i have a issue with what i think are exploding particles.
See the image attached or this link to the video https://vimeo.com/267554028
I read in the documentation that the volume needs to be closed so thats what i did. I still keep getting these lines. I managed to fix it enabling meshsmooth but i ideally don’t want to use it because it can cause flickering.
I also noticed enabling meshsmooth causing the edges of the simulator being visible as dark lines in the mesh.
Is there something i am missing?
Thanks in advance,
Stefan.
Hey, can you try a latest nightly and see if this improves, and if not, it would be very helpful if we can have a look at the scene.
Thanks!
Did a quick render on a still with the latest build and it seems to be gone. Im rendering a sequence now and will keep you posted on the progress.
Thanks!
Did a quick sequence render and its still there but to a lesser extent. I’m redoing the sim right now so maybe end of the day i will know if it worked. If not i will send you a mail via support@chasogroup.com.
Roger that, thank you very much! If it’s still there, we’ll figure it out and update you 
Cheers!
Did a quick check yesterday evening, it seems to be in the displacement texture and not the sim itself.
When i turn that of its works ok. Enabling it brings it back. Disabling motion blur shows the deformation spike of the mesh. Changing the detail doesnt fix it.
Roger that, got the scene as well. I hope in a few hours I’ll be able to update on what’s going on and how to fix it.
Cheers!
https://vimeo.com/267761986
New sim and render here on nightly from yesterday. Meshsmooth =1. Problem is still there, seems to be dependent on camera angle, it only occurs on second half of animation.
Disabling embree seems to fix it, at least on a still. rendering a short animation now to test.
:edit:
100 frames sequence seems clear of spikes, rendertimes doubled tho
Yes! Finally managed to reproduce it here as well! Let’s see what this is and how to fix it. Will ping you when I have more news
Cheers!
Hey again,
The rogue polygons are going to be fixed in tomorrow’s Phoenix nightlies. There still remains a problem when smoothing and ocean are enabled and you might get some missing polys on the simulator border…
Cheers!
Hi Svetlin, many thanks for looking into it!
Whats was the problem in the end, a bug of some sorts?
Will download the latest nightly tomorrow.
@simulation border, i will just render a few pixels more and crop in post, no problem.
Many thanks again!
Indeed, it was a bug Thank you very much for reporting this!
Hi Svetlin,
I installed the nightly from the 14th. I made a new sim and the problem is the same. It goes away when i only enable use embree and dont tick the use embree for mb box.
Using mb on a ocean without embree for mb enabled takes ages. Any thoughts on this?
Thanks in advance!
:edit:
Rendered a longer sequence and the problem is still there, also with just embree enabled.
Hey,
Can you send us the scene where you get the problem? Does it work for you with the scene you already sent us and the nightly build?
Thanks!
Its in various scene’s. Ive done some tests with various sims on low and high quality. I sent you a merged file with the sim file also.
Hey, thanks, got it! Looking at it right now - I need to enable Embree and increase Smoothing from 0 to 1, right?
On frame 535 I am not getting issues anymore with these options - either as they were in the scene originally, or when I change them. I am using V-Ray Next Beta 3 however. Let me try to switch to the latest stable of 3.60.04. This seems to be a V-Ray issue which I’ve worked around in Phoenix, but it might also have different behavior on different V-Ray versions…
Btw, in the scene there was a CameraShake plugin. Since the Phoenix ocean’s construction depends hugely on the camera, could it be that plugin which is causing the artifacts?
Will keep you posted, thanks again for helping catch this nasty issue!
Alright, got it with V-Ray 3! Seems like Mesh Smoothing is out of the question, since even with 0 the issue is still there.
Sounds like I need to hand this over to the V-Ray guys though - seems like the ocean renders fine with Scanline as well and since the issues seems to happen only with Embree, this needs to be looked at by the V-Ray devs.
Will update you again when I know more…
Hi Svetlin, thanks for the effort My bad, i should have told you that.
Your right, im on 3.60.04, windows 10 and windows 7, meshsmooth on and off.
Camerashake is a small wobble script, nothing fancy. Tried it with and without and it gives the same result.
Thanks again
Ah, just one thing - if you are using nightly ***49, there is a known crash if you are going to render fire/smoke with grid based self-shadowing - there is a new nightly from the same day - ***50, where this is fixed