wave5-physics-velocity-force-application

To apply forces to PhysicsVelocity in Unity DOTS without instability, write updates from a Burst ISystem scheduled in FixedStepSimulationSystemGroup and ensure it updates before PhysicsSystemGroup. This fixed-step ordering keeps your dynamic body simulation stable.

Applying a force to a static body in Unity DOTS Physics results in NaN errors because infinite-mass bodies have a zero inverse mass. You must guard against PhysicsMass.InverseMass == 0 to prevent NaN physics states and invalid motion.

To apply an impulse or one-shot initial velocity to a dynamic rigid body in Unity DOTS, update PhysicsVelocity directly from a system in FixedStepSimulationSystemGroup. This pattern handles initial velocity assignment after spawning and impulse-like gameplay interactions.

Yes, you can use Burst compilation with PhysicsVelocity updates for continuous force systems. You should write a Burst ISystem scheduled in FixedStepSimulationSystemGroup to apply continuous directional forces like gravity-wells, wind, or magnetic attraction efficiently.

Yes, you need to use fixedDeltaTime when applying continuous forces to Unity DOTS dynamic bodies. Correct use of fixedDeltaTime within the FixedStepSimulationSystemGroup ensures that your continuous force application and velocity integration remain mathematically accurate.

You should update PhysicsVelocity before PhysicsSystemGroup when applying custom gravity or wind forces. Using UpdateInGroup and UpdateBefore attributes provides the necessary ordering guarantees so the physics simulation processes your newly applied forces immediately.