Mesh.raycast: Check material.skinning before applying bone transform

[zach-capalbo]

#19178 introduced bone transformations during raytracing. However, if the object's material does not have skinning set to true, then it should not be applying the bone transformations. Since material.morphTargets is checked before applying the morph targets, it seems reasonable that material.skinning should be checked before applying bone transformations as well.

[Mugen87]

Since material.morphTargets is checked before applying the morph targets, it seems reasonable that material.skinning should be checked before applying bone transformations as well.

Well, the difference is that morphed meshes don't have a separate class like MorphedMesh. Hence, checking for the material property is the only way to figure out whether morph target animation is enabled or not.

In context of skeletal animation, there is SkinnedMesh. Using a mesh without setting skinning to true does not really make sense. So the additional check is somewhat redundant (although it's of course correct).

[zach-capalbo]

Using a mesh without setting skinning to true does not really make sense.

For context, in my use case (a model texture editor), I use material.skinning to toggle between skinning enabled and disabled. It's a lot easier and less error-prone than converting back and forth between Mesh and SkinnedMesh. Especially important to me to be able to toggle, since #19178 can cause a very large slowdown when raycasting a skinned mesh vs a non-skinned mesh.

I also have a quick-and-dirty workaround, if anyone needs it:

let oldRayCast = THREE.Mesh.prototype.raycast
var wasSkinned = false

THREE.Mesh.prototype.raycast = function(...args) {
  wasSkinned = this.isSkinnedMesh
  this.isSkinnedMesh = this.isSkinnedMesh && this.material.skinning
  let res = oldRayCast.call(this, ...args)
  this.isSkinnedMesh = wasSkinned
  return res
}

[mrdoob]

Thanks!