When you take a look at a particle simulation you can see differently coloured particles. :
These colours
- represent the particles' individual velocities or another property
- can be customized in the emitter's or domain's “Display” panel
- are available for other channels (vorticity, age, etc.) as well.
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When you render the particles everything will be displayed with the node's default → colour (see split image below). With “UV channel” it is possible to transfer the colour distribution to the rendered image. In conjunction with particles you simply have to choose a channel from
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Then, start the render, e.g. with → “Maxwell Interactive” ("FIRE" button from the “Render” shelf). Here is a comparison of a fluid render without and with activated "Velocity" channel:
Channels with Meshes
The concept, described above, is also valid for meshes (except the legacy type), but the workflow is different, because a Maxwell material is required. All relevant settings are located under Mesh > Node Params > Maxwell Render:
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