CFrame mnemonics
Methods
Certain methods on CFrame have an equivalent operator-based expression, which can be useful for understanding how they work:
| Method | Expression |
|---|---|
A:ToWorldSpace(B) | A * (B::CFrame) |
A:ToObjectSpace(B) | A:Inverse() * (B::CFrame) |
A:PointToWorldSpace(B) | A * (B::Vector3) |
A:PointToObjectSpace(B) | A:Inverse() * (B::Vector3) |
A:VectorToWorldSpace(B) | A.Rotation * (B::Vector3) |
A:VectorToObjectSpace(B) | A:Inverse().Rotation * (B::Vector3) |
Space-conversion analogy
CFrame multiplication is not equivalent to addition. However, certain aspects can be reused in order to remember how it works.
Pretend that A * B is analogous to B + A. Also pretend that A:Inverse() is
analogous to -A. There is no subtraction, but the formula B - A can be
rewritten as -A + B. So, when we see the expression A:Inverse() * B, it can
be thought of as a sort of B - A.
This explains ToObjectSpace. It “subtracts” the origin A from the subject B
to get the location of B relative to A. ToWorldSpace is the reverse; the
origin is added back to the subject to get the real world location.
| Method | Analogy | Rewritten | Actual |
|---|---|---|---|
A:ToWorldSpace(B) | B + A | A + B | A * B |
A:ToObjectSpace(B) | B - A | -A + B | A:Inverse() * B |