Imroved horizon mesh/subdivs for Ocean Mode.

[markus_s_cg]

I have been using Phoenix FD for many years, mostly for simulating oceans since one of my clients is a boat manufacturer. There is one thing I have struggled with, and I hope there could be some improvement in a future update.

When rendering Phoenix FD ocean with a VrayDisplacementMod on a simple plane (100x100 segments) the horizon looks great and very detailed with the default settings, and it calculates meshes fast without using too much memory. I use edge length 4 px for 1080, but for higher resolutions I increase edge length to conserve memory.

But when rendering Ocean with a simulation in Ocean Mode the horizon does not look as good in comparison. The ocean subdivs settings can improve things, I have tried to go as high as 6 subdivs, but it still does not look as good. If I go to 7 I run out of memory with 64GB and calculation of the mesh freezes. This is when rendering in Full HD 1920x1080. Also if I try to render images at higher resolutions for stills, I have to lower Ocean Subdivisions usually to around 1, and it looks quite bad.

I have rendered out some samples at different subdivisions to compare the results.
I was hoping the devs could figure out a way to solve the horizon subdivision mesh in a better way since a plane gives much better results compared to the ocean mesh generated by the phoenix FD simulation.

Images:

1. VrayDisplacementMod on a simple plane (100x100 segments). This looks best IMO.
2. Simulation in OceanMode Subdivisions = 4 Horizon roughness = 1
3. Simulation in OceanMode Subdivisions = 5 Horizon roughness = 1
4. Simulation in OceanMode Subdivisions = 6 Horizon roughness = 1
5. Simulation in OceanMode Subdivisions = 5 Horizon roughness = 0

[Svetlin.Nikolov]

Hey,

Yes indeed, the Phoenix Ocean Generates a real mesh, while V-Ray displacement does all its magic at render time, so it will certainly use less memory no matter what. The only alternative to getting ideal ocean subdivs without running out of memory would be to implement an entirely different ocean render mode - something like the Isosurface mode, but for meshes. I have this in mind, but it's not in the shortlist for now. Will add another vote to it so we know there is demand and it gets more priority. Thank you!

[markus_s_cg]

Thank you, is there a public vote for customers? Where can I add my votes for new features?

[Svetlin.Nikolov]

Ah no, the task list is private because some things there are not supposed to be seen because it could hurt either us or our partners. BUT make sure to tell us about anything you don't like or want added - we are keeping track.

[waaazoo]

+1 vote for this enhancement, off course !

[markus_s_cg]

Hi, I've been experimenting with putting a Vray displacement modifier on top of my Phoenix Ocean simulation. I have turned off the displacement on Phoenix itself. I know that it has some disadvantages, like not easily being able to attenuate by height and speed, no displacement on splash and foam particles etc, but I think it looks quite nice compared to the built-in Phoenix displacement. However I am experiencing some glitches that I don't understand, and I think they only happen when I use the vray displacement modifier on top of Phoenix. I have edited a short video to show it. This is my second attempt, and this happened similarly in different places in my first attempt as well.

if you look at the cryptomatte layer it seems like the glitch is part of the water/ocean. I also have acompressed Zdepth grab to show what is going on. Does anybody care to guess why this happens, or what is going on, or should I submit my scene to support?

[waaazoo]

Regarding the first post, did you ever try not to put horizon roughness at 1 ? I never put it so high.... I use mainly between 0.1 and 0.5.

[Svetlin.Nikolov]

Ah, the video doesn't seem to be working right now?

[markus_s_cg]

Sorry maybe I sent the wrong link (or posted it in a way that doesn't work). Try this. I uploaded it as unlisted on Vimeo.
Drammen_Night_Vraydisplace_oceanbug (vimeo.com)

[georgi.zhekov]

Hey,

Which versions of Phoenix and V-Ray are you using? How about if you get a latest Phoenix nightly build from here - https://forums.chaos.com/forum/phoen...nightly-builds
and the latest V-Ray build from chaos.com

If the issue is still reproducible - can you send over the scene through the support system here so that we can take a look (at the top right, there is a submit a request link) - https://support.chaos.com/hc/en-us

Thanks!

[markus_s_cg]

Regarding the first post, did you ever try not to put horizon roughness at 1 ? I never put it so high.... I use mainly between 0.1 and 0.5.

I've tried changing horizon roughness through the whole spectrum from 0-1, but I don't think it's getting anywhere close to the results you get from vray displacement. For the previous scene, and a few others I ended up rendering two versions of the water and mixing the horizon in post with the Z-depth layer. One with a displaced plane and one with the sim. It worked out pretty good IMO, but it's more time-consuming to do. Here is a link to that example: Hyke - Animert ferge - Hamburg on Vimeo

[waaazoo]

I've tried changing horizon roughness through the whole spectrum from 0-1, but I don't think it's getting anywhere close to the results you get from vray displacement. For the previous scene, and a few others I ended up rendering two versions of the water and mixing the horizon in post with the Z-depth layer. One with a displaced plane and one with the sim. It worked out pretty good IMO, but it's more time-consuming to do. Here is a link to that example: Hyke - Animert ferge - Hamburg on Vimeo

Well, I agree anyway that the horizon with Phoenix infinite sea is tricky and the results are half way satisfactory.

[markus_s_cg]

Hey,

Which versions of Phoenix and V-Ray are you using? How about if you get a latest Phoenix nightly build from here - https://forums.chaos.com/forum/phoen...nightly-builds
and the latest V-Ray build from chaos.com

If the issue is still reproducible - can you send over the scene through the support system here so that we can take a look (at the top right, there is a submit a request link) - https://support.chaos.com/hc/en-us

Thanks!

I'm using V-ray 5 update 2.1 official, and Phoenix 4.41.02 nightly. I'll try downloading a new nightly and re-render the frame where the glitch happens.
(edit: this build I think phoenixFD_adv_44102_max2021_vray5_x64_31049_instal l)

[markus_s_cg]

Ok, after installing the latest Phoenix FD nightly the result changed a bit, but there was still some traces of a glitch there.
After installing the latest Vray 5 nightly the issue almost looked like it disappeared, but inspection of the cryptomattelayer tells me that something is still going on with the water (som weird specs/grains)
Ill try to send a file to support later.

[markus_s_cg]

Hey,

Which versions of Phoenix and V-Ray are you using? How about if you get a latest Phoenix nightly build from here - https://forums.chaos.com/forum/phoen...nightly-builds
and the latest V-Ray build from chaos.com

If the issue is still reproducible - can you send over the scene through the support system here so that we can take a look (at the top right, there is a submit a request link) - https://support.chaos.com/hc/en-us

Thanks!

I've uploaded a scene file and some cache frames to to support now, after getting similar glitches in the latest nightlies.