Re: [Algorithms] Dummie Matrix math questions

[Aras P. <ar...@un...>]

> http://www.toymaker.info/Games/html/camera.html
> So, it appears that for the view, I will need to use the invert matrix after
> fixing the code, thats weird to me, does anyone knows a tutorial / doc that
> explain the math behind view matrix?

That tutorial explains "how to get axis vectors and position from a
matrix that is inverted".

If you think about a camera as a regular object, then camera's matrix
(camera-to-world) has a matrix just like any other object. In D3D's
notation, first three rows are axes, 4th row is the position. More
here: http://aras-p.info/texts/matrices.html

A view matrix is NOT camera's matrix; a view matrix does the opposite
transform (world-to-camera). Hence it's an inverted matrix of the
camera.

Now, an orthonormal camera can be inverted pretty easily; the rotation
part just gets transposed, and the position part is "the negative dot
product of the position and each of the axis vectors" (quoting your
tutorial link).


-- 
Aras Pranckevicius
work: http://unity3d.com
home: http://aras-p.info