These are small and simple tech demos showing different techniques. They are more complicated than the toolbar Quick Setup presets but are simpler than the big Example Scenes.
Page Contents
Droplet Splash
Body Force Text Fill up
Liquid Cascade simulation
Fire/Smoke Cascade Simulation
The scene shows cascading setup between two simulators. The Phoenix Source clamps the texture values between 0-1 so smoke and fuel will naturally transition fine, but temperature which goes above 1 - up to several thousand Kelvin - will need to be remapped before being plugged into the source. This is why an Output map is added after the grid texture reading the Temperature channel. The temperatures for the source for sim 1 and for the brush source are set to 2000K, and the Output Amount of the Output map to 1/2000 = 0.0005.
- You need to enable Motion Velocity on the Brush source so that the velocities will be transferred as well and of course you need to have velocity exported from the first sim.
- The area which overlaps will be rendered twice, unless you put a box as a render cutter for the first sim.
- Grid-based self-shadowing won't work between the cascade grids - you need to switch to the slower but more robust Ray-Traced self-shadowing.
Wind Tunnel
Smoke color by age
Unlike particles which have an Age channel, the voxel grid does not have such a channel, but it can easily be achieved by using the RGB color grid channel. In this scene, we emit white smoke from a Source, and a Phoenix Mapper using a Black texture Map and a long Buildup Time gradually modifies the RGB channel of the Simulator and darkens the white color over time. This way the oldest smoke has black RGB channel and the newly emitted is white.
The scene uses a cylinder emitting smoke. The Smoke Source has the Temperature set to 10 Kelvins so the smoke will fall down and the RGB channel is enabled with a white color set. The Mapper's Buildup Time is set to 2 seconds.
For the rendering the Smoke color is set to be based on Texture and an Output map is used. The Output map uses a Phoenix Grid Texture which reads the RGB channel as an input, representing the age, and then the color is remapped to create a ramp from blue for the youngest Smoke which has RGB of 1, through green, to red for the oldest smoke which has RGB of 0.
Gas stove flames
Tweaking of the following options has a significant impact on the final simulation’s result:
- Outgoing Velocity value in the source
- Grid resolution - for this kind of a scene it's pretty low
- Cooling - more cooling leads to shorter flames
- Steps per Frame - high values produce smoother flames
- Volumetric Options - tune the fire color, light emission, shape and a lot more from here
Hot steam
Smoke Inside of Text