PinJoint3D misbehaves

Question

Hi. I'm trying to use a PinJoint3D to attach RigidBody3D to StaticBody3D. And it works very weird - it doesn't keep distance (is very simple description of what happening).

Here is isolated example with a chain with 4 links. As you can see on video - the RigidBody3D-to-RigidBody3D seems work fine, but the StaticBody3D-to-RigidBody3D link doesn't - it.

Code of scene from video (no dependencies, just Godot 4.1): joints3d_lab_baked.tscn

with PinJoint2D I've tried the same and that works fine (and, unlike 3D, there are a lot of tutorials for this). But unfortunately I need 3D.

What I'm doing wrong?

Fleeta

Answer 1

I've fixed that. The problem was because the joint location. I haven't realized it's position defines the pivot point - I thought the swinging should be around the first node and joint is just a relations, which transform doesn't mean anything.

Weird that Joint is not mandatory to be a child of first node and in fact all thing works like it is child of first node (the absolute position of joint is remembered as mounting point relative the first node and moving with it like child does).

Fleeta