Jump to content
kemijo

How to use whitewater with deformed ocean only (no FLIP sim)?

Recommended Posts

I posted about this on the sidefx.com forums and got no response. This is about a feature that SESI has shown and discussed in the Houdini 17 Launch Presentation video. I'll link to the original post and copy it below.

https://www.sidefx.com/forum/topic/61375/

"In the Houdini 17 Launch Presentation video https://vimeo.com/293116223 [vimeo.com] at around 1:20:00, Scott Keating briefly shows and mentions using the whitewater solver for spray and foam with only a deformed ocean surface (no underlying FLIP sim needed). I can't seem to find anything on how to actually do this in Houdini 17. The whitewater nodes and shelf tool still expect a FLIP sim. Can anyone point to what I am missing?"

Anyone know how to do this? Or at least can confirm that this feature is missing? It'd be great to know either way. Thanks!

 

Share this post


Link to post
Share on other sites

When setting up your Whitewater Source SOP you can pipe the water (eg ocean) into the left input and any emitter you set up into the second input. I've only tried this one time but I used the cached out points from the water simulation rather than the surfaced data as the left input. For the second input you can use any geometry you want. Set an emit attribute on it then in the Whitewater Source turn off all of the Emit from Curvature, Acceleration and Vorticity. Instead use the Extra Sources (by enabling "Add Extra Sources") which by default uses emit attribute you already set up as the Emission Attribute. I used this method to generate whitewater from obstacles in the water (eg rocks) so I haven't tried it for what you want. However, (guessing a little here) you should be able to use something like this for generating whitewater from the surface too using traditional methods to isolate sources such as whitecaps. You'll basically need to grab the surface and make your own curvature, acceleration and vorticity calculations.  

  • Like 1

Share this post


Link to post
Share on other sites

Further thought: the easiest test would probably be just to isolate points in the whitecaps as your source, make sure they have velocity set  and set the emit attribute to 1 for those points and pipe that into the second input of the whitewater source as I described above to see what you get.

  • Like 1

Share this post


Link to post
Share on other sites

Hey! Sorry I didn't realize I had not responded to this. Grasshopper, yes I'm aware I can create my own source points to use with the whitewater solver, but it was designed to be used with a FLIP sim. I was asking about what Scott Keating suggested was a new feature in the linked video - using the whitewater solver with only an ocean spectrum. The shelf tool does not let you create the whitewater nodes unless you have a dynamic fluid node selected. Just checked the python lib that the shelf button runs, it still seems to expect a fluid node only in 17.5.

DANjustYEAH, nope, still no idea how to make this work as suggested in the video and no response yet from someone that knows whether this is a thing or not.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×