getClosestFacetAtCoordinates returning null most of the time

Questions
6

Thank you for the thorough explanation - finding the closest facet on a mesh is a critical function for what I am doing. I am trying to think of ways to make this more accurate (projecting to a plane within the bounding box etc.). If you know about something I can do, let me know.

It is currently replacing the following function, which as you may imagine is very slow:

/**
 * Finds the point that is closest to the part's mesh. 
 * @param {Vector3} point
 * @return {Vector3} Closest point on the Part Mesh
 */
closestPointOnPartMeshTo(point) {
    var positions = this._partMesh.getVerticesData(BABYLON.VertexBuffer.PositionKind);
    var minSquaredDistance = Math.pow(10, 9);
    var closestVertex = BABYLON.Vector3.Zero;
    var numberOfVertices = positions.length / 3;	

    for (var i = 0; i < numberOfVertices; i = i + 1) {
        var vertPosition = new BABYLON.Vector3(positions[i*3], positions[i*3+1], positions[i*3+2]);
        var dsq = BABYLON.Vector3.DistanceSquared(point, vertPosition);

        if (minSquaredDistance > dsq)  {
            minSquaredDistance = dsq;
            closestVertex = vertPosition;
        }
    }    
    return closestVertex;
}