Guided ocean sim - similar to Maya Bifrost

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Scott Broad
Posts: 7
Joined: Fri Nov 24, 2017 5:43 pm

Guided ocean sim - similar to Maya Bifrost

Post by Scott Broad » Fri Nov 24, 2017 5:58 pm

New to Realflow 10, and have been looking for info with no luck yet.

Is there similar functionality in Realflow to the Guided Simulation setup using Bifrost in Maya?

Specifically:
- create an ocean wave mesh using Realwave, BOSS or Houdini Ocean and cache as alembic (no particle sim yet)
- use that alembic mesh as a "Guide" for bifrost particles
- create an "Emission Region" to localize the particle emission(polygon object, animated or not)
- use animated geo(boat) as a collider, previously animated to follow/react to the cached ocean waves
- simulate particle waves, then foam with this setup.

No containers needed, no invisible walls creating incorrect splash-back. This method allows for art and animation direction specific to the ocean waves and boat prior to sim.

I have seen the Hybridio setups where one sims the boat through the flat fluid volume, then adds displacement afterward. While this setup looks good in the end, it doesn't allow for proper animation direction of big waves and boat interaction along them, only sort of faking it after the sim...

If in fact a "guided sim" workflow exists in Realflow 10 I would appreciate a point in the right direction.


Thanks.
-Scott

Thomas Schlick
Posts: 178
Joined: Tue Aug 29, 2017 12:35 pm

Re: Guided ocean sim - similar to Maya Bifrost

Post by Thomas Schlick » Mon Nov 27, 2017 8:56 am

Hi Scott,

I've only heard of Bifrost's guided simulations, but I don't know how they actually work. Anyway, there are methods to use RealWave, imported alembics, or displacement maps as a basis for Hybrido, but not straight out of the box. One idea is to use the "Ocean Force" daemon. This daemon also uses an ocean statistical spectrum (OSS) and you can synchronize the daemon's OSS with your RealWave surface. Both share the same parameters. The daemon also accepts image maps to drive the waves, e.g. displacements maps from BOSS, RealWave, or any source. Maybe that's the easiest solution.

Another method uses RF's graphs system, but the entire process requires several steps: you have to load the ocean surface and calculate the vertices' velocities first. From this velocities you create and record a field, and save it as an OpenVDB sequence. In your Hybrido simulation you load the OpenVDBs through graphs again, and convert them into a force field. This field can be used to drive the Hybrido simulation.

Scott Broad
Posts: 7
Joined: Fri Nov 24, 2017 5:43 pm

Re: Guided ocean sim - similar to Maya Bifrost

Post by Scott Broad » Mon Nov 27, 2017 8:56 pm

The guided sim setup is handy.

I'll have a look into the Ocean Force daemon first... Like I said, new to Realflow.

Just want to find the best way to simulate over top of an animation/art directed ocean wave. Something that has been specifically created for a scene or sequence of animation with particular angles in mind.

Thomas Schlick
Posts: 178
Joined: Tue Aug 29, 2017 12:35 pm

Re: Guided ocean sim - similar to Maya Bifrost

Post by Thomas Schlick » Tue Nov 28, 2017 10:26 am

Yes, I also think that the Ocean Force daemon should be the first to start with, esp. when you don't have too much experience. Here are two tutorials I've found and maybe they'll help you to get started:

http://bit.ly/1N76Jj1 (for RF2015, but still 100% valid)
http://bit.ly/2zKY1KT (4 part series from my colleague Luis Miguel Mora)

Cheers,
Thomas

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