Large Beach Scene

[Syu_z]

I need to create a beach scene with camera views from above the ocean, moving forward to the beach, not from a high angle so I will be seeing the ocean details and all. The screen is going to be 180 degree curve, so the area that we will be seeing is absolutely massive. I was thinking of maybe creating cascading simulator for different parts of the ocean with lower grid res, kind of like LOD for the ocean, because if not the amount of cells will be ridiculously large. I was wondering if there's a better way to achieve this? I am not sure if this is the best solution, or if it's possible to cascade to so many simulator around it.
I saw in some other thread that there's a way to mix the dumb infinite ocean with the sim, but that seems to be only applicable if the camera is looking out from the beach into the ocean, where the simulated waves can hide the calmness of the infinite ocean. Any ideas?

[georgi.zhekov]

Hey,

Using cascade setup for such a shot might not work so well I'm afraid. The cascade works best for shots where the fluids move from one simulator to the next one but if it the liquid has to move back and forth between the two the results might not look good.

May be you can run a single or a few simulations for the shore and instance those out. Using the options in the Input rollout you should be able to offset the animation so that it won't look repetitive.
Then if you're using 3ds Max you can put all of them in Ocean render mode and this will merge them into one single ocean surface. At the start of the render it will prompt a window to notify you which will be the main simulator that will control the material and the render settings for the rest. You can choose which simulator would be the main one using the Maxscript option called oceanpriority - you can find more about it here - https://docs.chaosgroup.com/display/...endering-Ocean

If you need some wave crests outside the simulator then probably you could use the Foam texture for the shading - https://docs.chaosgroup.com/display/...oenixFDFoamTex

Hope this helps!

[Syu_z]

Sweet! I was just about to ask again because i saw this in Phoenix Key Features:

"Seamlessly transition from procedural ocean to simulated beach waves."

So I was wondering there must be something I miss. Ocean render mode might be the solution. I will try this out immediately. I have given up with the cascading since it doesn't look like it merged well at all, and opted for one single massive sim. Unfortunately, even 100 mil simulation is not cutting it. Thanks for the timely response.

I don't really need wave crests outside of the sim since most of the ocean images I'm seeing doesn't really have them until it reaches the shore. Point mode is not supported with gpu yet, correct? In the meantime I'm using bubbles to render the splash and foam.

[georgi.zhekov]

Yes, Points mode is still in the to do list for V-Ray GPU, but you can use bubbles mode or use V-Ray Instancer and instance some small spheres over the Phoenix particles as a workaround for now.

[Syu_z]

Hi again, sorry. So far I've gotten the method to work so that's a big help. Thanks!

I was looking through the oceanpriority explanation but there's no documentation anywhere about it except that page, I am not sure how to get it to work. Would you mind elaborating a bit on it? I am just a dabbler in maxscript. I tried to show $ on the simulator but there isn't any parameters that's called oceanpriority.

I assume it will follow the displacement and levels and all, what about the foam and splash shader, does it have to be created separately per duplicated liquid simulator?

Edit: Looks like without the oceanpriority, the duplicated simulator is not merging well with the main oceanmesh mode. If i turn on oceanmesh mode for all 3, I seem to have overlaps of the ocean and my fog color becomes quite intense.

[georgi.zhekov]

Hey,

So in order to merge multiple simulators in one ocean mesh - you need to put all of them in Ocean mode (also make sure they have the same position on the Z-axis, otherwise the ocean level won't match between them). That's it. What the oceanpriority option will do is let you choose which simulator will be the main one, controlling the render settings for the merged ocean. If you can't see the option then you probably are using an older version of Phoenix. This one got introduced in the latest Phoenix 4.40 release. In the older versions you can't choose the primary simulator and it is chosen automatically for you. At the start of the render you should get a warning box telling you which one will be used.

In order to use the ocean priority, just select the simulator that you wish to be the main one and in the MaxScript editor type $.oceanpriority = 2 (or any other value - the higher the value, the higher the priority will be).

As for the Particle Shaders - it's best to use separate ones for each simulator.

Cheers!

[Svetlin.Nikolov]

Hey,

Just a couple more notes to cleat things up - no matter what your ocean priority is, the mesh will be the same. Only the material will be taken from a different simulator.

However, note that if you want to merge simulators into one ocean, they SHOULD NOT overlap. They need to have at least a little space apart from one another.

Cheers!

[Syu_z]

Thanks a lot for the explanation, georgi and svetlin. Updating Phoenix and giving it a little space did the trick. There are artifacts present though, in the merging of the sim to the infinite ocean, as shown by attached image.

Edit: Another question, wetmap are not supported on gpu yet?

[Svetlin.Nikolov]

Hey, looking good! Do you mean some visible seams to the far right of the image?

The particle texture that is needed for rendering the wetmap is not ported to GPU yet I'm afraid

[Syu_z]

Thanks! No, not the seam. Do you see the intense blue artifacts close to camera, somewhere south of the image? The one that looks like world map. I am not sure how to get rid of that.

[Svetlin.Nikolov]

Ah, could it be that these are some air pockets between the bottom of the beach the and the liquid? Can you try moving the render geometry of the shore up so it intersects the simulated mesh more?

[Syu_z]

Hmm, doesn't look like it. In this image i increased the render geometry of the shore by 10 cm to ensure it's intersecting the simulated mesh. If you see the one with the oceanmesh mode, you can still see the artifact. It doesn't seem to be present in the render without oceanmesh mode.

[Svetlin.Nikolov]

Huh, haven't seen such artifacts before... Is Phoenix in the left image in Mesh mode?

Also, which exact V-Ray version do you have and is this V-Ray GPU?

[Syu_z]

Yes, the left is Mesh mode. V-Ray 5, update 1.2 (5.10.02) build 30713. Phoenix is 4.40.00. Yes, V-Ray GPU on RTX 3090. Maybe I will check CPU result as well.

If needed, I am able to upload the simulation for checking purposes. Let me know.

UPDATE: Same deal with CPU renderer, the artifact is still present.

[Svetlin.Nikolov]

Ah yes, if possible, compare it to CPU first, and if this doesn't provide any useful insights, then maybe sharing the scene will be the next step.

Thank you!