Hi All,

Looking to use a Solid Particle System to distribute trees across a scene. I have a `.glb`

file which is my tree mesh, and another which loads in the tree positions through a collection of transformNodes.

In doing so though, all of the tree generated via the particle system seems to have been turned inside-out, reversing their normals. The original mesh is on the left, a tree rendered with a particle system on the right.

My tree mesh is imported to the scene with:

```
BABYLON.SceneLoader.LoadAssetContainer(
"assets/3d/",
"tree_2.glb",
scene,
function (container) {
const treeMesh = container.meshes[0]
// add our tree mesh
container.addAllToScene()
BABYLON.SceneLoader.LoadAssetContainer(
"assets/3d/",
"tree_positions.glb",
scene,
function (container) {
let treeMat = treeMesh.material
var positions = []
for (var n in container.transformNodes) {
let node = container.transformNodes[n];
positions.push(node.position)
}
var posFcn = function (instance, i) {
instance.rotationQuaternion = null;
instance.rotation.x = Math.PI / 2;
instance.rotation.y = Math.random() * Math.PI * 2;
instance.position.x = -0.01 * positions[i].x
instance.position.y = -0.01 * positions[i].z
instance.position.z = 0.01 * positions[i].y
let scale_factor = (Math.random() * 0.2) + 0.9
instance.scale.x = instance.scale.x * 0.01 * scale_factor
instance.scale.y = instance.scale.y * 0.01 * scale_factor
instance.scale.z = instance.scale.z * 0.01 * scale_factor
}
var sps = new BABYLON.SolidParticleSystem('Tree Particle System', scene, {updatable: false});
sps.addShape(treeMesh, positions.length, {
positionFunction: posFcn
});
const spsMesh = sps.buildMesh();
sps.mesh.freezeWorldMatrix();
spsMesh.material = treeMat
}
);
}
)
anything obvious I'm doing wrong here?
```