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Fix: Erratic collision response when using constraints on colliders
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Authored by Benjamin Meyer (Anvilarion) on Apr 3 2019, 2:30 PM.

Details

Summary

If a collider has a constraint on it, its behavior in a simulation is non-deterministic. It may be, that the collider is ignored completely (see left object in the video below) or that it exerts a violent collision response on collision (see right object in the video below). Which one occurs may change if the simulation is run again.

The reason for this is, that the collision modifier does not wait for constraints to be evaluated which results in the simulation assuming a false position of the collider. Even worse, if the constraint is evaluated before the collision modifier in one frame and after the modifier in the next frame, the simulation assumes a high velocity of the collider and thus creates an according collision response.

This patch fixes that behavior by introducing a dependency between the collision modifier and the position of its object:

Diff Detail

Repository
rB Blender

Event Timeline

This revision was not accepted when it landed; it landed in state Needs Review.Apr 4 2019, 11:06 AM
This revision was automatically updated to reflect the committed changes.