Expose PhysicsDirectSpaceState.intersect_point() to scripting

[fossegutten]

Describe the project you are working on

3D first person shooter

Describe the problem or limitation you are having in your project

When using RayCast that starts and ends inside a shape, an intersection is not detected.
I need to know if the raycast starts inside an Area or not.

Describe the feature / enhancement and how it helps to overcome the problem or limitation

Expose intersect_point from PhysicsDirectSpaceState to GDscript.
This is already exposed in 2D

Describe how your proposal will work, with code, pseudo-code, mock-ups, and/or diagrams

PhysicsDirectSpaceState.intersect_point(.....)

If this enhancement will not be used often, can it be worked around with a few lines of script?

Will be used often, cant be worked around.

Is there a reason why this should be core and not an add-on in the asset library?

It already exists in engine, just needs to be exposed.

[Xrayez]

When using RayCast that starts and ends inside a shape, an intersection is not detected.
I need to know if the raycast starts inside an Area or not.

Perhaps could be fixed by godotengine/godot#41347.

[Calinou]

For the record, this is how intersect_point() is exposed in the 2D physics server:

• https://github.com/godotengine/godot/blob/43e96e0c652cd2ed41a1b9dfb7989ff272607a88/servers/physics_server_2d.cpp#L357-L359
• https://github.com/godotengine/godot/blob/43e96e0c652cd2ed41a1b9dfb7989ff272607a88/servers/physics_server_2d.cpp#L409

This will require a bit of refactoring as no such method exists in 3D. Besides, if backporting this to 3.x is desired, it needs to be exposed in both Bullet and GodotPhysics.

[20kdc]

EDIT: these notes are for 3.x

Bullet and GodotPhysics seem to have intersect_point, and the class structure involved here suggests that exposing it in the base class would do so in both.

"common code" style for _intersect_ray: https://github.com/godotengine/godot/blob/3.x/servers/physics_server.cpp#L252

Implementations of intersect_point:
https://github.com/godotengine/godot/blob/3.x/modules/bullet/space_bullet.cpp#L65
https://github.com/godotengine/godot/blob/3.x/servers/physics/space_sw.cpp#L53