Imported mesh doesn't collide with the ground

[Pietro]

Hi guys, I’m trying to place an object on the ground but it won’t stop falling when it collides the ground. What am I doing wrong? Please help me, thanks

Babylon.js Playground

[Takemura]

Your meshes[0] from .glb is a root-mesh without any vertices, so using BoxImpostor won’t work on root-mesh.

A similar issue is discussed here:

Better way to give physics to imported GLTF/GLB scene meshes?

Hello, I have a question with a Playground link now! I’m trying to add colliders (aka “impostors” in Babylon) with the default CannonJS implementation, and it’s messing up the locations and rotations of all my objects from the original scene. Here is what my scene is supposed to look like: [Screenshot_20230126_103033] Here is what my scene looks like after I assign impostors to all my meshes: [image] From what I understand, this is a side effect stemming from the impostor creation system…

Or use AmmoJS like this:

Babylon.js Playground

With AmmoJS you could even just use MeshImpostor on root if I remember correctly.

[carolhmj]

A few things about your PG:

• I highly recommend using our V2 Physics API with Havok as it’s way more performant
• You shouldn’t create a physics object and use checkCollisions, as the latter is just for camera collisions and conflicts with the physics engine
• The UFO object is complex to treat with physics because it has skeleton animations, so I opted to stop all running animations to make handling easier.
• As Takemura said, the root mesh doesn’t have any vertices, so the impostor/aggregate creation won’t know its size. Instead of using the root mesh, I created a new parent for it that represents a collision box, and made it invisible, so the collisions will happen on this parent.

Here’s the updated PG with the changes: UFO Physics | Babylon.js Playground (babylonjs-playground.com)