What is the difference between TransformDirection, TransformVector and TransformPoint since they all accept and return a Vector3 value.

I am a little confused about the these three functions as they accept and return a same kind of variable that is a Vector3. I would really like some passerby to leave me a few words of clarification on this topic.

Erm, yes, the Vector3 system in Unity (or in Mathematics for that matter) requires a little imagination.

Remember that a Vector consists of a Direction and a Distance.

Remember that Vectors are totally Commutable (They can be moved around and the same vectoral representation holds true).

In Mathematics we put a line over the Algebraic term to indicate its a Vector. In Unity we need to tell the compiler HOW to interpret the Vectoral information in the same way we tell it how to interpret Variables (int, float etc).

(1.0, 1.0, 1.0) is a point in space. Using a little imagination we can also consider that it can also represent a Vector IF WE ASSUME that the start of the Vector is at (0,0,0). This is the information that is missing and why it confuses you. Back to remembering that Vectors are commutable and suddenly you can see that this (1.0, 1.0, 1.0) can represent a vector of that direction and length anywhere in space. It still looks the same as a point in space but WE KNOW ITS NOT and we need to tell Unity how WE see it and would like to use it.

I presume TransformDirection returns a Unit Vector indicating a direction with no distance.

I presume TransformPoint returns a point in space.

I presume TransformVector returns a Vector which contains Direction and Distance provided you use the assumption that 0,0,0 is the starting point (dont worry its commutable).

This infomation will all look the same but you know its not.

Is any of this making sense? Feel like I’m rambling.