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Guided Ocean vs Wave Tank?

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Ocean experts -  what is really the difference these days between a Guided Ocean and just a Wave Tank? Are Guided Oceans just legacy and no use anymore?

Pros and Cons?  

Cheers!

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On 2022. 01. 07. at 12:25 PM, HM_2020 said:

Ocean experts -  what is really the difference these days between a Guided Ocean and just a Wave Tank? Are Guided Oceans just legacy and no use anymore?

Pros and Cons?  

Cheers!

To me this made it clear: https://www.sidefx.com/docs/houdini/fluid/oceans.html

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Cheers but that still does not really explain the real difference.  Both are spectra driven, one acts like a "collider" that the sim sits on... is that REALLY it?  What would be the reason to use one over the other?

 

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14 minutes ago, HM_2020 said:

Cheers but that still does not really explain the real difference.  Both are spectra driven, one acts like a "collider" that the sim sits on... is that REALLY it?  What would be the reason to use one over the other?

 

According to my understanding only Guided Ocean what is really spectra driven. Wave tank only uses spectra to initialize the waves, but "after the initial frame, the simulation will begin to deviate from underlying ocean spectrum." At least I think that is REALLY it. I mean it's not a trivial thing :)

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I'm not an expert on oceans, but I've been trying to get up to speed for a new project. The way I understand it:

Guided Ocean - waves are formed primarily from the ocean spectra with a FLIP sim of a thin layer of particles riding on top of the ocean spectra. This means that the spectra take priority in shaping the look of the ocean and the depth of the sim is limited. That's why the link above says it is best for shallow objects like a boat (or a sea otter) moving through an ocean, where the ocean waves are the primary thing determining the look of the ocean.

Flat tank - is a completely flat FLIP tank where you can add back in some of the high frequency spectra at render time to blend the sim with the surrounding ocean. Best for interactions where the interaction of the sim and colliders is the dominant thing determining the look of the ocean in the area of the sim. Say a monster (or a radioactively enlarged sea otter) trashing about in the water. The waves are pretty secondary here in determining the look of the sim compared to the monster thrashing. You might just add back in some of the high frequency ocean spectra for blending but its your monster (or giant otter) doing the work.

Wave tank - is a FLIP tank where the initial state is derived from the ocean spectra and from there it's a full-blooded FLIP sim (although you can blend back in spectra as above if you want). A big wave crashing into a lighthouse is what I think of here (no ideas how to use an otter with this one).

 

Edited by madebygeoff

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yes i think all have been said. both setup are based on a similar setup but not identical. both initialize the wave tank in a different fashion one use Guided Ocean Layer the other Wave Tank

Guided Ocean Layer : Generates a thin layer of particles on top of a guiding ocean surface. The particles are initialized with ocean velocities. The guiding ocean surface and velocity volumes are used both as a boundary layer and as a guiding surface to drive the thin layer of particles. This preset is most useful for simulating the ocean surface where closely matching the underlying ocean spectrum surface is necessary.

Wave Tank : Generates a full tank of particles initialized with ocean velocities as well as boundary layer surface and velocity volumes that can be used to update the simulation velocity in the boundary layer. This preset is most useful for simulations that require a full liquid simulation including interaction with deeper parts of an ocean.

- You will use guided ocean layer when you have a large ocean with precise look define in the spectrum , then you want to have a FLIP sim splash in a small area of that ocean, but you want to be able to perfectly match the Flat ocean geo and the FLIP sim meshed geo at render time, accuracy is key here you need perfect match between deformer and simulation. 

- wave tank is just a way to art direct your flip, to give him a turbulent ocean pattern, basically you art direct the shape of your ocean with your spectrum, then you tell to your FLIP ok i want you to move like this but you keep your freedom during the simulation time. The goal is not to match a deformer , the goal is to define a wavy turbulent behavior in your FLIP sims

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Cheers all.  This is the key I was trying to determine... can a Wave tank still match the spectra on its edges... and seems sort of using the boundaries, if large enough will smooth out the sim in middle as it nears edge, to then match Spectra.   Although can look a bit strange if you have much vel and details that then must slow down and flatten to the edge.

And yes Guided wont give you nice rolling waves, it will simply follow the spectra, so a wave may rise and start but will never make a "pipe" like surfers ride.   So in the end a Wave Tank is best to use if you want some nice pipes and splashes that then mix into a Spectra.

I also did wonder if Guided would somehow be faster to sim but its not really.

 

 

Edited by HM_2020

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