Get specific collisionShape when KinematicBody has multiple collisionShapes

[AlexZan]

Describe the project you are working on:
I am working on a block building vehicle prototype. A vehicle can have thousands of blocks. There can be many vehicles per game.

I have one kinematic body for a vehicle so that I can move it, then I load all the blocks in as collision shapes with mesh instances within them.

Describe the problem or limitation you are having in your project:

I cannot seem to get reference to the collision shape I am "hitting": My player has a melee attack block, it has an attack script with an area and a collision shape.

I have tried get_overlapping_bodies()

and the signal

func _on_Area_body_shape_entered(body_id, body, body_shape, area_shape): print(body_id, body, body_shape, area_shape)

I am always getting reference to just the kinematic body. But it does not seem possible to get the collision body I am actually hitting.

Describe how this feature / enhancement will help you overcome this problem or limitation:

provide reference to the specific collision shape when a kinematicbody has multiple collision shapes

Show a mock up screenshots/video or a flow diagram explaining how your proposal will work:

not applicable

Describe implementation detail for your proposal (in code), if possible:

not applicable

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

The work around would be to check each collision body for collision, but thats on potentially 10,000+ blocks. Also I dont want my blocks to have any attack checking responsibility.

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

It is fundamental to reference a node responsible for collision, no matter what node setup.

[Jummit]

This seems like a bug. Report it on the Godot Engine Github:
https://github.com/godotengine/godot/issues

[AlexZan]

Well the function and signal are working as intended it seems, there just is no feature currently to get reference to the collision shape

[KoBeWi]

body_shape_entered( int body_id, Node body, int body_shape, int area_shape )
Emitted when a physics body enters, reporting which shapes overlapped.

That totally sounds like what you need. Then use shape_owner_get_owner(shape_find_owner(body_shape)) to get the shape.

[AlexZan]

@KoBeWi that seems to provide the id of the collision shape that is attached to the player Area, not the other "enemy" collision shape. Which I already have since my player is "attacking/hitting" from the area collision shape. What I need is the collision shape that my collisions shape hit. (one or more, of many, since the enemy kinematic body can have many collision shapes as children)

[KoBeWi]

Uh, I think it should've been
body.shape_owner_get_owner(body.shape_find_owner(body_shape))
Anyways, the function does what you want to achieve. But you need to use it correctly.

[AlexZan]

@KoBeWi I had tried this before also, this only gives the id of first collision shape, no matter which collision shape i am entering

[KoBeWi]

So yeah, I tested it and there's a bug. Also turns out a similar bug was already reported: godotengine/godot#19290
Closing this.