There are three ways to source with Paradigm, Particles, VDBs, Houdini Height Fields, and primitive shapes that come with the Paradigm toolset called Source Shapes.

Particles

You can connect particles to the 3rd input of the solver. You can create these any way you want however there are a few things to keep in mind.

Emission

If you give the solver points to source it will emit all the particles every time step.

If you wish to emit particles only on the first frame you will need to animate the source to achieve this. You can also use the “Paradigm Source Particle” node that has options to control emission timings.

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Remember that with the pressure force if you continuously emit particles in the same location overlapping particles will cause an expansive force in order to maintain the particles separation. If you need to continuously emit it’s recommended to make the particles separation of the source point cloud larger than the simulation particle division size.

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Particle Attributes

You can source the following particle attributes.

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Remember to enable them in the output tab if you need them post-simulation.

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• Velocity as a vector 3 “v”
• Temperature as a float “temperature”
• Color as a vector 3 “Cd”
• Viscosity as a float “viscosity”

Extra Particle Properties

If you need particles to keep certain attributes from the source particles you can define them in the output tab.

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Not all types and sizes are supported. Only float, half, & integer types as scalars, vector3s, and vector4s.

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