Add warning for using concave shape on CharacterBody3D

[bikemurt]

As per #86574

Tested a simple scene to confirm that ConcaveShapes do not work for collisions on CharacterBody3D (same as RigidBody3D).

Added the following node config warning:

I didn't update the language documentation as I assume that's handled separately

Bugsquad edit:

• Fixes No warnings when using ConcavePolygonShape3D with CharacterBody3D #86574

[AThousandShips]

This wording isn't correct, it should be more clear, CharacterBody3D does support this shape, it just isn't recommended:

When used for collision, ConcavePolygonShape3D is intended to work with static CollisionShape3D nodes like StaticBody3D and will likely not behave well for CharacterBody3Ds or RigidBody3Ds in a mode other than Static.

The warning should match the one for RigidBody3D instead

Resolved

[bikemurt]

ConcavePolygonShape3D doesn't support RigidBody3D in another mode than static.

RigidBody3D uses this wording, so would we change both of them?

Initially I found this description to be wordy, but I see what @AThousandShips is saying - you can use concave shapes, it just won't work with moving bodies.

[AThousandShips]

The warning should be descriptive, so it shouldn't be changed for RigidBody3D IMO, but both could be updated, on second thought I'm not 100% sure what is meant by the static mode here, or if it applies to both types, the documentation for the shape should probably be improved to clarify this 🙂

I would suggest to update both descriptions to be clearer that it's not recommended to use these

Edit: It might refer to the freeze mode of RigidBody3D, but that is very vague and unclear, unsure how to approach this here

[AThousandShips]

The physics team would have to confirm but I think the documentation for the shape needs to be made more clear, something like:

When used for collision, ConcavePolygonShape3D is intended to work with static CollisionShape3D nodes like StaticBody3D and will likely not behave well for or RigidBody3Ds (except when frozen and freeze_mode set to FREEZE_MODE_STATIC) or CharacterBody3Ds.

Or something like that

And then change all the wordings here to align with that, saying something like "not recommended", take the scale warning below as a reference

I think wordiness here is not a problem, on the contrary the warning should be clear and detailed to avoid confusion and misunderstandings 🙂

[bikemurt]

I just did a little bit of testing by using a RigidBody3D (with convex collision shape) and pushing it into a RigidBody3D and CharacterBody3D, both with concave shapes.

When the RigidBody3D is set to freeze/static, the concave shape does actually work for collisions. It behaves exactly like a StaticBody3D in that case.

I think CharacterBody3D does not work at all with a concave collision shape (as far as I can tell). It doesn't interact with a StaticBody3D (my floor) or the RigidBody3D with a convex shape.

When used for collision, ConcavePolygonShape3D is intended to work with static CollisionShape3D nodes like StaticBody3D and will likely not behave well for or RigidBody3Ds (except when frozen and freeze_mode set to FREEZE_MODE_STATIC) or CharacterBody3Ds.

I like this. Could split out the description for RigidBody3D and CharacterBody3D:

RigidBody3D:

When used for collision, ConcavePolygonShape3D is intended to work with static CollisionShape3D nodes like StaticBody3D and will likely not behave well for or RigidBody3Ds (except when frozen and freeze_mode set to FREEZE_MODE_STATIC).

CharacterBody3D:

When used for collision, ConcavePolygonShape3D is intended to work with static CollisionShape3D nodes like StaticBody3D and will likely not behave well for CharacterBody3Ds.

Edit: looks like there is probably one more comment to clean up, but I haven't worked with WorldBoundaryShape3Ds so I'm not sure what the comment should actually be.

WorldBoundaryShape3D doesn't support RigidBody3D in another mode than static.

[bikemurt]

Here's what I have for now. Also added a new line so it looks a little cleaner:

[milkiq]

Here's what I have for now. Also added a new line so it looks a little cleaner:

It looks nice! Easier to understand than before

[Calinou]

I suggest adding the same warning for VehicleBody3D and VehicleWheel3D, as these have the same constraints due to their dynamic nature.

[bikemurt]

I suggest adding the same warning for VehicleBody3D and VehicleWheel3D, as these have the same constraints due to their dynamic nature.

Makes sense. I took another look, and it appears that VehicleBody3D is (currently) the only node that inherits RigidBody3D. So I updated the code to use a string substitution in the RTR - not sure if we prefer writing out the strings verbosely.

Also, to me it seems that VehicleWheel3D shouldn't have a CollisionShape3D added to it since it doesn't inherit CollisionObject3D, so I didn't add a warning for that.

Edit: I should say that there's a separate warning for attempting to parent a CollisionShape3D to a VehicleWheel3D, so that's covered

[Calinou]

Tested locally, it works as expected.

[akien-mga]

Looks good! Could you squash the commits? See PR workflow for instructions.

[bikemurt]

Sorry - missed that in the documentation for amending commits. Will do it that way next time

[akien-mga]

Thanks! And congrats for your first merged Godot contribution 🎉