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The Whitewater tool on the Particle Fluids shelf creates spray, foam, and churn based on an underlying FLIP fluid simulation. It sets up the source and solver for a whitewater simulation. Whitewater emission particles are created from a source FLIP or liquid simulation based on several criteria including fluid acceleration, curvature, and vorticity. The simulation uses these emission particles and volumes from the fluid simulations as sources for simulating whitewater with foam, spray and bubble particles.
Do not try to set up a whitewater simulation from scratch.
For more information on how the tool sets up the network, see the Whitewater shelf help.
Whitewater distribution is similar to Pyro clustering in that the different simulation nodes don’t have to communicate with one another. The results should generally be the same between distributed and non-distributed, except for the Preserve Foam option, which looks at overall foam particle density to affect particle life. You may need to adjust the particle density downwards when running distributed.
The following is a simple example to illustrate how to set up particle fluid distribution with whitewater.
Create a FLIP Tank from the Particle Fluids shelf.
Click the Whitewater shelf tool, select the
fliptanknode in the
AutoDOPNetwork, and press Enter.
Click Distributed Particle Fluid from the Particle Fluids shelf, select
whitewater simnetwork, and press Enter.
The shelf tool creates an HQueue simulation ROP to send the distributed sim to the farm, as well as a Null in the Whitewater DOP Network called
DISTRIBUTE_whitewaterobject1_CONTROLS. The only relevant parameter is really the Slice parameter. The tracker has to be there, but like clustering, the different simulation nodes don’t communicate during simulation. It also creates a set of nodes to save the slices to disk in
whitewater_import, as well as a File Merge SOP called
load_slices to load them back in.
The distribution is controlled by spatially dividing the emission of whitewater particles in the
WhitewaterSource node. On the Distribution tab, the Division Type can be Surface Bounding Box or Specified Box. Surface Bounding Box expands to the bounding box of the incoming liquid’s surface SDF. Specified Box lets you specify a box size, or press Enter and manually adjust it in the viewport.
The bounding box is then divided up according the Divisions across each axis. The Current Region parameter controls the current emission region being simulated and is tied to the
DISTRIBUTE_whitewaterobject1_CONTROLS Slice parameter.
Setting the Division Type back to None will disable Whitewater Distribution.
To change which slice you're viewing while testing distribution , click Edit > Aliases and Variables and changing the Slice variable.
How to animate a wave tank with whitewater
This tutorial explains how to get a nice looking wave tank in the viewport and flipbook. This is useful to see how the waves will move and where whitewater will be created.
Press D to open the Display Options dialog.
On the Geometry tab, turn off the Display Sprites checkbox.
Create a Wave Tank using the tool on the Oceans shelf tab.
wavetanknode, lower the Particle Separation value to
0.07. This will create a better looking wave tank.
Navigate back to the OBJ level and click the Whitewater tool on the Oceans shelf tab. Select the tank when prompted to add whitewater to the existing network.
On the Guide tab of the Whitewater Object, turn on the Color Particles By Type checkbox. This will cause the foam particles to be displayed white, the spray particles to be displayed green, and the bubbles to be displayed red.
You can turn off the display red and green particles by diving into the Whitewater Solver and turning off the Enable Spray checkbox on the Spray tab, and Enable Bubbles checkbox on the Bubbles tab.
Stay inside the
whitewater_simnode and play your scene. If you leave the
whitewater_simnode the particles will appear black.