Flickering mesh and Foam shader

[kangoocarl1]

I did make a Vray combo material wiht the FDOceanTex and teh FDOceanTex (as instructed in the manual).

This material - applied to a sim - looks and renders great when just rendering an ocean scene with "ocean mesh" (and not rendering any sim particles). Even the foam of the texture looks and mooves very realistic.
So far so good.
Now applying the material to the same simulator and rendering it not as "ocean mesh" but as "mesh" (mesh generated from the simulated liquid particles...) I do get extreme flickering from frame to frame. I have tested with high meshsmooth settings (also using the "use liquid particles" setting for mesh smooth) in myny variations but the ocean and foam (textures) flicker and "jump" terrible form frame to frame.

Is the Oceantexture and/or FoamTexture "not" ment to go onto a "mesh" and only ment to go on an infinite "ocean mesh"? Or am I doing something wrong? How can I get rid of the flickering?

Other idea: do I need more particles (grid resolution)? I already highered the number but same result.



Thanks for any advice!

[georgi.zhekov]

It should be working fine in Mesh mode.

Could it be that you have Play Speed below 1 in the Input rollout?

Can you show us how the flickering looks and your settings?

Thanks,

[kangoocarl1]

Hello Georgi,

playspeed is set to default (1).

- Simulation settings screenshot attached
- FDTextures Setup Sscreenshot attached

And here´s a preview to a 1 sec looped render with the flickering in OceanTex and FoamTex on the mesh (no particles rendered):
http://download.martinhausler.com/ph...flickering.mov

[georgi.zhekov]

Looks fine from the screenshots - can you send us the scene so we can check it?

[kangoocarl1]

Sure - here´s the scene file for download:
http://download.martinhausler.com/sc...AN_flicker.zip

Scene without the sim-files (please resim locally, too much data....).

[Svetlin.Nikolov]

Hey, haven't checked the scene yet, but off the top of my head - in the Foam Texture, make sure to disable 'Use the original non displaced vertices'.

[kangoocarl1]

Svetlin, Georgi,

the "use the original non displaced vertices" option was enabled, so I did disable but the result is really bad (ocean surface now looks totally unreal, soft, and flickering is still is there). As far as I understand (and read the manual) the "use the original non displaced vertices" option needs to be enabled if applied to simulators, doesn´t it? (as here I am applying it to a FD simulator)?

If you guys can please investigate the scene file I sent - I am very stuck here. Thank you!

[georgi.zhekov]

Does it help if you turn off your motion blur?

[kangoocarl1]

Here´s the sim without motion blur (again 1 second looped):
http://download.martinhausler.com/scene_tests_02.mp4

The second animation following in this clip is the exact same texture/foam material on an ocean mesh (instead the mesh form the particle simulation):
On the ocean mesh the water-texture "travels" with the water (the bumps, the foam etc) and it looks like water.
On the mesh instead it loooks very weird as every frame the texture is totally changing (the bumps, the foam etc.) and so it flickers and does not look like water at all.

[georgi.zhekov]

In your scene the isosurface level is set to 0 - set it to 0.5 and it will look a lot better.You can find what it does in here - https://docs.chaosgroup.com/display/...ing-Parameters

Cheers,

[kangoocarl1]

I have set the isosurface level to 0.5 (and afterwards also tried other numbers... - same flickering, did not change or fix it ;(

[georgi.zhekov]

Did you try to increase the grid resolution ? When your camera is so close to the surface you will need a lot more resolution. You can increase your smoothing value to 10-20 as well. This would smooth out the surface as well.

[kangoocarl1]

Georgi,
so much higher mesh smooth (20+) did fix most of the flicker. It´s not completely gone but something to work with. Will also try more grid resolution (already did increase) and see how it goes. Thanks for all the hints and helping me figuring this out.

Martin

[kangoocarl1]

Update;
All fixed - no more flickering - last "bit" of flicker did disappear after I reduced the alpha of the FoamTexture material (in the VrayBlend material combo) just a few percentages (now on 97%) as well as played with brightness and contrast of the alpha for the foamtexture (in the color correction node for the foamtexture´s alpha channel). Not sure why it flickers on 100% - maybe it´s a light reflection thing.

However: for anybody running into the same kinda problem, here´s my hints:
- much higher grid values
- much higher mesh smooth values
- Look out for the FoamTexture´s alpha brightness, contrast and overall opacity

Also I am using unusual lighting of the scene (with a "classic" lighdome and HDRI texture) and maybe this is involved. Tested wihtout lightdome - also got flickering but much less in the first place.