Flow v1.0

Flow is a tool for simulating water in a variety of ways, with very simple setup. Given an input height field as 'terrain', starting water height and water input, it calculates the flow of the water across the given 'terrain' for some realistic results.

Each pixel is treated as a 3D column of depth alpha. Water is added on top of the given terrain and it's flow into adjacent pixels is calculated based on the height difference and the user controlled flow rate. Due to the nature of this method, water can't travel faster than a pixel per frame, so for large scale images re-timing will be necessary for faster effects.

Colour can be simulated, although blending is assumed to be instantaneous, meaning small colour additions to larger bodies of water will be less noticeable.

Example file included.

Inputs:

- Terrain: A 2D heightfield, the pixels alpha value is treated as the height. This is read per frame, and although it can be animated, it will not exert any force on the water which could lead to unusual results.

- Source: Per frame water addition to the scene. Evaporation / drains can be simulated with negative values.

- Water: The starting water heights. These are added to the terrain, so flow could begin immediately.

Simply place the Flow folder in your plugins directory and add using nuke.pluginAddPath()

More information can be found here.

Flow - Water Simulation in Nuke from Matthew 'Rick' Shaw on Vimeo.