Ocean displacement houdini ( spectrum )

[nezgro79]

Hello! I'm still wondering how I can re-create the ocean shader with Arnold.

How can I reuse the spectrum displacement shader created to get more details about my ocean?

I've been looking for weeks and I can't find much for Houdini, but there's a lot of rendering but no one explains how to do it, I tried a method I found here but nothing to do ...

I plan to buy Arnold to be able to work with it and it's really a big brake, I have the choice between getting by with mantra that does the rendering but very slowly, or Arnold without knowing how and paying a license.

If anyone has a solution, please share.

Have a nice day.

[jamie.portsmouth]

I'm not too familiar with how ocean surface simulation and rendering is done in Houdini, but it seems from a quick look that a combination of the
Ocean Spectrum node and Ocean Evaluate node can be used to generate the geometry. Then it would be a matter of assigning an Arnold shader to the geometry.

For further effects like whitecaps and spray, some more advanced setup would be required involving e.g. a particle system and/or volumes.

[nezgro79]

Hey, thanks for the answer.

What I'd like to do is get some details from the displacement map but I don't know how to use it in the standard arnold shader.

[jamie.portsmouth]

So if you have Houdini generate a displacement (either scalar height-field or vector displacement), you can connect this to the displacement input of the Arnold material to have it apply this to the geometry at render-time. For an ocean, presumably the base mesh would be a plane (you may need to tesselate it to get a reasonable amount of detail after displacement).

See the docs here: https://docs.arnoldrenderer.com/display/A5AFHUG/Displacement

[jamie.portsmouth]

See also the replies here: https://answers.arnoldrenderer.com/questions/25292/ocean-vector-displacement.html

[nezgro79]

Thank you i will try later

[nezgro79]

Hi i have tried and i have generate my displacement map but when i render i have nothing on my plane

https://youtu.be/O4mpDrzEEAI

i try to have this

https://docs.arnoldrenderer.com/display/A5AFHUG/Vector+Map

[julian.hodgson]

It's on our roadmap to support the ocean spectra directly with an arnold shader (htoa#866).

[nezgro79]

Great but i need to make it i have tried like this but i dont have a good result

https://youtu.be/O4mpDrzEEAI

[brian_Foley · Accepted solution]

Your Ocean Network is cutoff in the video but I think your problem is you need to disable the render flag on the render grid.

The way Houdini sets up the Ocean node is with a 1 poly grid set to render(purple) which gets picked up by other nodes but only works with Mantra. You need to disable the render flag on this node (or add uvs and subdivisions but the first way is better).

Right click on the ocean preview node and set it to render. Make sure you have uv's. Turn off Deform input Geometry (this is suppose to be just a preview node but you are using it to render in this case).

On object level add the subdivisions you need.

You can also click on Deform Input geometry and skip the vector displacement in the Arnold shader.

Rohan has a tut for redshift and Octane but the setup works for Arnold

https://www.youtube.com/watch?v=O6tGJ0SpgdE&t=73s

Here is a beach wave tut that uses Arnold.

https://www.youtube.com/watch?v=vNiGXODwvTw

[nezgro79]

Thank you i will try today.

There is another vidéo with full screen

https://youtu.be/O4mpDrzEEAI

[nezgro79]

Its ok now thank you !!!