3d-programming

Ok, I am new at this, so here is my problem,
I try to learn some 3d-programming(for gameprogramming), and I know there is a standard 3d-matrix that describe a 3dobjects position in the world, if I understand it right its a 4*4 matrix which describe the objects position in the world, its facing and so on.. but I do not know how it really works, can any one direct me to some site with detailed description or can email me or answer my question in any way, please :=) ??



Comments

  • I'm not sure what youre asking,

    I do some maths in college.. all i know about Matrix calculation can be found on few maths websites. ( search the net for Maths) These people might know a bit more about Matrix for 3D programming.


    : Ok, I am new at this, so here is my problem,
    : I try to learn some 3d-programming(for gameprogramming), and I know there is a standard 3d-matrix that describe a 3dobjects position in the world, if I understand it right its a 4*4 matrix which describe the objects position in the world, its facing and so on.. but I do not know how it really works, can any one direct me to some site with detailed description or can email me or answer my question in any way, please :=) ??
    :
    :



  • I know how it works, they are called homogeneous transformation matrices and represent rotation, translation and scalation between 2 axis systems. You must notice that they only refer to axis systems, not objects, so you must always have one fixed reference system which is the world, and then each matrix represents subsequent transformations.

    1 0 0 0
    0 cosA -sinA 0
    0 sinA cosA 0
    0 0 0 1

    this matrix represents only one rotation of A degrees in X axis, so a null rotation gives

    1 0 0 0
    0 1 0 0
    0 0 1 0
    0 0 0 1
    which is the identity matrix,

    cosA 0 sinA 0
    0 1 0 0
    -sinA 0 cosA 0
    0 0 0 1
    this matrix is the same but in Y axis

    cosA -sinA 0 0
    sinA cosA 0 0
    0 0 1 0
    0 0 0 1
    this matrix refers to Z axis

    1 0 0 x
    0 1 0 y
    0 0 1 z
    0 0 0 1

    this matrix translates a distance given by the vector p(x,y,z)

    the element 4,4 represents the scalation factor, and the elements 4,1 4,2 4,3 represents a change in perspective.





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