RW - Basic Workflows

Owned by thomas (Unlicensed)
Last updated: 02 May, 2014

This chapter introduces a couple of fundamental workflows for RealWave, showing you how to establish particle-wave or wave-object interactions, for example. The advantage is that everything is kept as easy as possible and in most cases you really just have to make a few clicks. The result of these settings is a complex interplay of RealFlow’s different solvers and wave surfaces. 

RealWave's parameters are split into two parts:

  • The mesh settings where you can define things like polygon size, foam map size, or the interaction between waves and the coast line. These parameters are available when you click on the RealWave node: Node Params > RealWave

  • The modifier settings. These parameters are only available when a modifier (e.g. “Fractal” or “Gerstner”) has been added. To add it, right-click on the RealWave node and choose a wave type from the “Add” submenu. Then, expand the RealWave container, and highlight a modifier. The settings are located under “Node Params”.

Adding a Modifier

Adding a new RealWave surface is just a matter of seconds and as always you have several options:

Icon Bar > RealWave > Surface

Main Menu > Edit > Add > RealWave > Surface

Nodes > RealWave node > Right-click menu > Add > RealWave > Surface

 

From this simple operation you get a plain mesh without any waves or displacement information. The easiest way to add structures to this plane is the use of a modifier:

  • Right-click on the RealWave node.

  • Expand the “Add Wave” submenu.

  • Choose the desired modifier and click “Reset” to see the structures.

  • Optional: repeat the third step for additional modifiers.

Dynamic Objects and Particle Interaction

When an emitter or object is added to a scene with a RealWave surface, you will notice a new panel under “Node Params”, called “RW Particle Interaction”, respectively “Realwave”. This set of parameters controls the entire interaction between the particles and the ocean surface. Bodies and particles have the ability to create secondary small waves, just as in real life where splashes produce ripples on water surfaces. You can control everything from impact strength to wave speed with these settings. When particles interact with a surface they can also contribute to a foam map. For the interaction with dynamic bodies, the appropriate feature has to enabled under the object’s node settings first. Additionally the (rigid) body should be made moveable, otherwise only static interactions, like wave reflections, are possible:

Node Params > Node > Dynamics > Active rigid body / Soft body

Node Params > Rigid body > Dyn Motion > Yes

Finally you have to adjust the appropriate RealWave parameters of the currently selected object. This panel is only visible with a RealWave surface in your scene and contains all necessary settings, including the option to generate foam maps:

Node Params > Realwave

Another method is the usage of particles to create small ripples or fine surface structures. In combination with RealWave, particles act like small objects causing more or less strong impacts disturbing the and displacing the mesh. Similar to rigid bodies, emitters also have an individual RealWave panel:

Node Params > RW Particle Interaction

 

Rain drops from particles on a RealWave mesh.

 

Rigid/soft bodies and emitters (particles) share some parameters, for example wave speed and texture strength. In the same way as with rigid bodies, the RW Particle Interaction panel is only visible with an already existing RealWave node. Additionally, there are two extra emitters that will only work in connection with a RealWave object:

  • Object splash

  • Crest splash

Foam Maps

Foam maps are created from interactions between particles from all kinds of emitters or objects and the RealWave surface. Each particle can print a mark onto a projected texture map. The intensity and life-span of these spots is controlled by a few parameters. Objects can also contribute to foam maps. To activate the generation of these maps a certain switch has to be turned on from the RealWave node’s parameter window:

Node Params > Realwave > Calculate texture > Yes

Particles as well as objects have a special parameter called “Texture strength” to control the strength of the energy samples on the final map. This setting can be found under the emitter’s/object’s “Realwave” window. By default it is already set to 1.0 and normally you do not have to think about it anymore. The last step is to prepare the output functions for the image sequence:

Export Central > REALWAVE > Realwave node > Foam texture (*)

That is actually all you need. The appropriate settings for ageing and propagation are also made under the RealWave node’s settings. More particles create better foam maps, because the distance between the individual samples is reduced. This leads to a denser map with better visible foam. RealFlow provides a realtime preview in the viewport. To see the evolution of the maps, switch to the smooth shaded mode:

View > Element or Scene > Smooth Shaded

Please note that the map preview is only available during simulation. During playback you will only see the last simulated foam map, but not the changes over time. To get a better view of the maps the particles should be made invisible:

Node Params > Display > Visible > No

Particle Layer

In many cases it is necessary to create splash particles from moving or impacting objects, add foam particles, or simply use fluid particles in combination with waves and objects. Under such circumstances you will often need a connection between the RealWave node's mesh and the particles from different emitters. With “Particle layer” you can easily transform the vertices and polygons of the RealWave mesh into particles. These particles cannot move freely; they are glued to the mesh and follow exactly any motion of the waves. Wave particles can now be combined with emitter particles, giving the impression of a seamless water surface.

 

A RealWave surface in "Particle Layer" mode and the meshed particles with activated "Velocity" channel.

 

RealWave particles are influenced by destructive daemons, like "k Volume". With this daemon the particle layer starts disappearing. To avoid this, it is a good idea to make “k” daemons exclusive to emitter particles in the “Relationship Editor”.