Offset drag instantiated scenes that result in a collision by its bounds to mitigate overlap

[ryevdokimov]

• Offset drag-instantiated scenes to place them on top of the targeted surface, raised along the surface's normal.
• Fix dragging behavior and appearance of scenes that have top-level set to true. Now, they can be positioned like non-top-level nodes while being dragged. Once they're dropped, they will remain at the same global position with their top-level flag set to true.

@cooperra

Before:

2024-02-18.13-38-22.mp4

After:

2024-02-18.13-37-09.mp4

[Cammymoop]

Could have a proposal since this is added functionality, if so I would also suggest adding this functionality to the move and/or select mode tools because this could be quite useful for them as well and isn't easily recreated by any other existing functionality afaik.

Regarding the implementation, how does it interact with non-axis aligned surfaces?

[ryevdokimov]

Regarding the implementation, how does it interact with non-axis aligned surfaces?

I need to get back into this, but I believe that preview nodes are packaged into a temporary node that is not rotated, so the bounds are always axis aligned. My current issue is that the scenes origin isn't always the center of the AABB, so that needs to be factored into the offset, if that even makes sense.

I would also suggest adding this functionality to the move and/or select mode tools because this could be quite useful for them as well and isn't easily recreated by any other existing functionality afaik.

Would be cool.

[Cammymoop]

I need to get back into this, but I believe that preview nodes are packaged into a temporary node that is not rotated, so the bounds are always axis aligned. My current issue is that the scenes origin isn't always the center of the AABB, so that needs to be factored into the offset, if that even makes sense.

Yeah, I mean, if the the surface you're instancing onto is not axis aligned, not the scene you're instancing. Does it stick the center of the closest aabb side to the surface or something?

[ryevdokimov]

Does it stick the center of the closest aabb side to the surface or something?

The current mechanism for Godot is to use the intersection of a viewport ray and a collider (which doesn't have an AABB), to determine the global position of where to instantiate the scene. This means that currently you can't snap to meshes without colliders, and the collider shape doesn't necessarily have to match the mesh.

I do have this PR: #87969 that does factor in the target AABB by using meshes instead of colliders, but it has its own issues. The answer for an ideal solution that encompasses flexible snapping to whatever layer is probably somewhere in between. An interesting and maybe dumb idea is to temporary build a collision sibling similar to how you can manually do in the editor via:

and then snap to that. It's a tricky problem.

[Calinou]

Tested locally (rebased on top of master 3576e84), it works as expected. Code looks good to me.

This will be good to go alongside #96740 to improve its usability 🙂

[akien-mga]

Thanks!