DirectX8 - normalised vectors

[danday1974]

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

[Fox]

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

[Zaei]

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:

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.

[danday1974]

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

[CornedBee]

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).

[Zaei]

Righto, CornedBee =).

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

Z.