By default, the Mesh will check to see if its model or view transform has changed each frame and only recalculate the vertex positions if they have.
This avoids lots of additional math in the
preUpdate step when not required.
However, if you are performing per-Face or per-Vertex manipulation on this Mesh,
such as tweening a Face, or moving it without moving the rest of the Mesh,
then you may need to disable the dirty cache in order for the Mesh to re-render
correctly. You can toggle this property to do that. Please note that leaving
this set to
true will cause the Mesh to recalculate the position of every single
vertex in it, every single frame. So only really do this if you know you