Batch Adding and Removing Bodies [SYNTH-253], et al.

[azaleacolburn]

Task

SYNTH-168 (Symptom)
SYNTH-191 (Symptom)
SYNTH-253 (Cause)

Symptom

Spawning fields rapidly causes Jolt to crash. According to Jolt documentation, this can happen when there are too many bodies in the broadphase tree arranged in an unoptimized manner.

Solution

According to the Jolt documentation, there are two ways to ensure optimization, the first is to batch adding bodies, so they can be added and arranged in a more efficient manner. The second is to call OptimizeBroadPhase() on the jolt body interface. There's significant overhead to the second option, and its not recommended with single-threaded Jolt, so instead, we batch adding bodies of a MirabufSceneObject.

Turns out, we actually do need to call OptimizeBroadPhase() anyway, to reset the broad phase tree structure. This means that this PR probably doesn't make spawning mirabuf scene objects any faster, but should stop spawning fields from crashing and speed up fields with lots of bodies.

Source

Verification

• Fission builds
• All tests pass.
• Sequentially spawning fields with multiple bodies doesn't cause Jolt to crash.
• Performance for fields with many bodies is significantly better on my machine.

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