parts of foam are black

[paul_merzliakov]

I'm running a liquid/ocean simulation of a catamaran sailing through the water at 6 knots. Rendering in Vray 6 Maya and the particles are in point mode.
Parts of it appear black and I have no idea what the issue could be.

[Svetlin.Nikolov]

Hey, could it be that these are the particles below the water surface? Could you do a test - please switch to Mesh mode instead of Ocean Mesh and see if anything in the particle render changes. If it does, then you might need to add some geometry below the water to act as the bottom - this way V-Ray would know how thick the Fog color of the vraymtl should be. Btw, are you rendering with V-Ray CPU?

Thank you!

[paul_merzliakov]

Hey,
I tried switching to mesh mode and the particles still appeared black.Yes, I'm rendering with Vray CPU. here's the full screenshot of the mesh mode render

[georgi.zhekov]

Hey,

Can you send over the scene so that we can take a look what is going on? You can either attach it here as a zip file or send it through the form (there is a link Submit a request in the top right corner).

Does it help if you reduce the Point size in the Particle shader or if you decrease the Shadow Strength?

[slavina.nikolova]

Also, does it help if you enable the Render as Geometry option from the Particle Shader rollout?

[paul_merzliakov]

Hey,
Slavina I tried the Render as Geometry, but that made no noticable difference. here's the zipfile of the scene file. The hdri I used is part of a free pack. if you want to use it, it can be found here https://cgi.tutsplus.com/articles/fr...hdris--cg-5684
thanks for giving it a look.

[slavina.nikolova]

Hey,

Thanks for the scene, we'll check it out and update the thread when we know more.

[slavina.nikolova]

Hey,

Everything seems fine here. I used the scene that you sent, simulated and rendered it. Tried with Mesh and Ocean Mesh Render Modes and the artifacts are not visible. I rendered a couple of frames around the 360th frame - from your screenshots it looks like that the artifacts are appearing around those frames. I'm using Phoenix 5.01 Nightly from 12.12.22 and V-Ray 6.

Could you tell us which are your exact Phoenix and V-Ray builds?
In order to find out the exact Phoenix version you can check the About info window: Maya > Top Maya Phoenix FD Menu > About Chaos Phoenix. You can find the V-Ray version in Maya > Top Maya V-Ray menu > About V-Ray.

Also, could you send us a cache file where the artifacts are visible to you?


Thanks!

[paul_merzliakov]

versions used:


Maya 2023,

V_ray v6.00.02

Phoenix fd 5.01.00


As for sending a cache file, they are around 150 MGB each, so im having trouble sending one over.

[slavina.nikolova]

Hey,

You can send it through our support contact form or you could upload it to Google Drive, Dropbox or similar.


Thanks!

[paul_merzliakov]

alright here it is: https://drive.google.com/file/d/1JVV...ew?usp=sharing

[slavina.nikolova]

Hey,

Thanks for the cache file! Are you rendering with V-Ray IPR? If so, could you try with Production mode and see if this helps.


Thanks!

[waaazoo]

it looks similar to my issue which has not been addressed for now.

[Svetlin.Nikolov]

Yup, I thought the same, but it might be a different thing in the end. We'll ping when we know more...

[paul_merzliakov]

This may or may not be related but is it normal to have water inside the geometry even if it's water-tight like in this screenshot? at first, I thought there must have been some unwelded verts I missed in my boat model, but then I tested it with a cube, and sure enough, there was still water in it. keep in mind this cube has all its sides, I just assigned a material that had 0% opacity to the side facing the camera to see the interior of the cube.