Draw handles for custom script shape2d member in editor scene view

[hsandt]

I added my own shape2d member to a custom script as exported var, so I can edit it numerically in the inspector. However, I cannot edit it via the usual handles in the scene, unlike native nodes having such a member.

I would need to add a CollisionShape2D to benefit from the shape editor, and reuse that shape in my code. However, I don't need the collision part so that would be a waste.

There is a similar issue in Unity where you'd often create Box and Polygon Collider components just to benefit from a shape editor, but only care about the shape itself, not the collision. However, I was also able to create more lightweight shape data members or components in this engine because I know how to draw polygon handles easily.

I'm not familiar with handle drawing in Godot. I know there is an API for this, but I'd rather avoid writing my own code for this as the native shape editor used for collisions is already pretty good, and writing a full polygon editor with filled color, etc. would be overkill for what I need.

Is there any easy way to reuse the native collision shape editor for non-collision shapes, without having to create a CollisionShape2D node?

Because if not, I'd like to submit a proposal for this. Although I don't have a clear idea of how it would look like, nor how we would code the thing (an annotation on the shape member maybe?), so I thought the discussion format may be appropriate for this.

Also applies to 3D shapes and 3D equivalent classes, although I'm not using those at the moment.