The mass of a point. Used by the Simulate Particles and Simulate Rigid Bodies nodes as well as several compounds to calculate the effect of forces.
If Mass is not defined, the Simulate Particles node uses a default of 1.0, so that forces have a one-to-one effect on velocity.
The Simulate Rigid Bodies node uses a default of 0.1 if Mass is undefined.
If Mass is defined but equal to 0.0, forces have no effect using either of the Simulation nodes.
You can quickly get and set the Mass attribute for particles with the Get Particle Mass and Set Particle Mass compounds.