Proving some stuff about Andi's transform code at https://github.com/mcclure/lovr/commit/0fe0751fccca7e6c2f3c0046a03f1806a78c8e11
This applies a transform to a vector:
function Loc:apply(v)
return self.rotate * (v * self.scale) + self.at
end
And this lets you compose two transforms together: