Attach (Child)Rigidbody TO (Parent)Rigidbody let it collide with Tilemap

We want to attach a (Child)Rigidbody to another (Parent)Rigidbody so that the (Child)Rigidbody is also transformed on (Parent)Rigidbody transformation.

The other constrain is that the (Parent)Rigidbody contains a tilemap also with collisions.

So we want the (Child)Rigidbody to:

  • inherits the (Parent)Rigidbody transformation when it is ON the (Parent)Rigidbody
  • collide with the tilemap ON the (Parent)Rigidbody
  • be able to leave the (Parent)Rigidbody and move freely in the world space.

During our tests, no game or physic-engine is able to do this. Eg.

  • Box2d
    • is not able to transform a world
    • applying parent forces to the child gives inacurate results
  • Unity
    • “nearly” can do it with (Parent)Rigidbody->Static Tilemap but transforming the Static Tilemap gives inacurate results.
  • Godot
    • “nearly” can do it, the same way as unity, but also gives inacurate results, when moveing Static Tilemaps. Also some (already reported) physic bugs renders godot unsuited.

We already consider to build a custom physic engine, but this will be a huge task we like to avoid.

We are searching for a way to do this, if you know an physic engine that supports this please speak up :).