DirectX8 - normalised vectors

Hi just a quick check on my understanding of something if thats cool guys - normalised vectors,

(0,1,0) - up
(0,-1,0) - down
(-1,0,0) - left
(1,0,0) - right
(0,0,1) - into the screen
(0,0,-1)-towards me

Correct?

I take it u can use decimals but they have to add up to 1 right?

Cheers

Dan

Depending on the 'VUp' vector setting for your world.. this might be true.

Not add to one, the length of the vector must be one. For instance, (0.5, 0, 0.5) is NOT normalized. Now, the length of a vector is:

Code:

---

sqr(x^2 + y ^ 2 + z^2)

---

To normalize the vector, simpy divide each component by the vector's length.

You can also use the D3DX functions for this stuff.

Z.

does d3dxvec3normalize do the job 4 u if u pass it (0.5,0,0.5) for instance?

PS I assummed the world up vector was the default (0,1,0) earlier

Cheers

Dan

Yes.
The D3DX* functions also have the advantage that they'll use cpu optimizations (e.g. MMX), whereas code you write might not (depending on compiler and settings).

Righto, CornedBee =).

Any vector where one direction is 1, and the others are 0, is normalized.

Z.