Matrix question

Think of it as a NULL for transformations. So in the same way that a pointer set to NULL means nothing for addressing memory, an identity matrix will not do anything to whatever you multiply by it. So if you transform a bunch of vertices by the identity matrix then the result will be exactly the same as the input.
The identity is commonly used to reset the transformation matrix to a null state before applying new transformations, so that transformations don''t interfere with each other when they are not wanted to.


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Never eat anything bigger than your own head.

NULL don¨t it sounds like the empty subspace.
And id is full rank.

Hey what do one use 1 for... is it usefull?

a * x = b
((1/a)*a) * x = (1/a)*b
(1) * x = a\b
x = a \ b

So without identity how would we define inverse.

One can..

Edited by - micca on December 5, 2001 4:26:23 AM

Biggles.... WTF are you doing in here... I mean... nothing...

I know basic Matrix stuff.... but nothing bout identity maticies.. guess thats why I failed my maths paper again

Thanks for the comments, I guess D3D does something deep in it''s bowels with the ID Matrix.

It doesn't.

The above usage of the identity matrix to define inverse is just that, you don't use it to caculate it.

You don't actually use it in code (unless to reset a matrix variable). At least I've never come across it, has anyone and if so when?

Edited by - d9930380 on December 5, 2001 7:00:36 AM