solved Mesh vs AbstractMesh

[Art Vandelay]

Hi everyone,

What's the difference between Mesh and AbstractMesh? I understand the Mesh extends AbstractMesh but I am trying to understand when I should use one and when I should use the other. An example would be great as well.

 

Thanks!

[Sebavan]

basically you should not use abstractMesh on your own as this is the common parts between Mesh and InstancedMesh. Since a couple of weeks ago you can create a TransformNode if you need to group Meshes under a transform a bit like in unity.

 

[brianzinn]

I have never used it directly, but often need to declare it in TypeScript in function parameters for Typing, ie: for PickingInfo.pickedMesh:
https://github.com/BabylonJS/Babylon.js/blob/01a11b0a4dcd1a195e9ca0b179852006f978ad9a/src/Collisions/babylon.pickingInfo.ts#L14

Here is an example of current state of VR Experience Helper (may change before 3.1 final) for setting a predicate for selection:

let experienceHelper = new BABYLON.VRExperienceHelper(scene);
experienceHelper.onNewMeshSelected.add((mesh: BABYLON.AbstractMesh, eventState: BABYLON.EventState) : void => {
  console.log('selected', mesh.name, mesh.isPickable)
})

If I was in JavaScript would not be using AbstractMesh, though.  If you don't know the difference - TypeScript transpiles down to JavaScript and all the typing information is lost anyway.

Also, would say that having "Abstract" in the name of the class is a good indication that you would not create your own instances (ie: abstract classes cannot be instantiated).

[RaananW]

AbstractMesh is selected here because all Meshes derive from it. We already had an internal discussion about the name, which all of us kind'a agree - It is not the most fortunate name. Having said that - it will not be changed. You can always cast to Mesh (if you feel like it will look better in code).