PhysicsDirectSpaceState2D.intersect_shape stops working when there are lots of Area2Ds - Githubissues

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PhysicsDirectSpaceState2D.intersect_shape stops working when there are lots of Area2Ds #94367

Open bogcow opened 3 months ago

bogcow commented 3 months ago

Tested versions

4.2.stable

System information

Windows 10

Issue description

Calling the function PhysicsDirectSpaceState2D.intersect_shape returns an empty array when there are many nearby overlapping Area2Ds. GIF 7-14-2024 5-39-03 PM In this GIF, the red circle is the intersect_shape call being made every physics frame. The lighter blue circle is the Area2D that we are trying to intersect. The darker blue circle is 3,000 Area2Ds on a separate collision layer. Notice how the size of the return results array goes to 0 as the mouse gets closer to the 3,000 Area2Ds. You would expect that the results size is 1 as long as the red circle is over the lighter blue circle.

Steps to reproduce

Download the MRP
Enable visible collision shapes
Try mousing over the Area2Ds

Minimal reproduction project (MRP)

IntersectShapeTest.zip

AThousandShips commented 3 months ago

Can you please try with 4.2.2 to make sure it's still occurring

rburing commented 3 months ago

This is because of the following:

https://github.com/godotengine/godot/blob/97b8ad1af0f2b4a216f6f1263bef4fbc69e56c7b/servers/physics_2d/godot_space_2d.h#L108

It should be documented and/or made configurable.

Making it configurable would require moving some memory allocations:

https://github.com/godotengine/godot/blob/97b8ad1af0f2b4a216f6f1263bef4fbc69e56c7b/servers/physics_2d/godot_space_2d.h#L111-L112