Thanks Geometrian for posting that code. I haven't worked in C++ for about a year so I will have to take a bit of time to dig into that and see what I can glean from it.

Since my post I have found a few more examples and articles but I am still a bit off on my calculatios. I am sure some will laugh but the formula I found that cracked everything open was **not** a formula to create the matrix but a formula that allowed one to pull the degrees of rotation out of the matrix. I took it and just reversed it, then from there I knew where to place the results and I figured out matrix multiplicaion.

But like I said things are bit off. There are some built in functions for simplifing rotation (they are limiting what I can do), and I am comparing my numbers to them. If I just rotate on one axis the numbers are fine it is when I rotate on more than one that things get messed up.

I have my code outputing the numbers from the built in rotation fuctions (first matrix below) and from my calculations (second matrix below), here's what I am seeing

X: 2deg
Y: 2deg
0.9993908270190958, 0.001217974870087876, -0.03487823687206265, 0,
0, 0.9993908270190958, 0.03489949670250097, 0,
0.03489949670250097, -0.03487823687206265, 0.9987820251299122, 0,
99.93908270190957, 100.06088018891836, 0.002125983043832047, 1
X cosine: 0.9993908270190958
X sine: 0.03489949670250097
Y cosine: 0.9993908270190958
Y sine: 0.03489949670250097
0.9993908270190958, 0, -0.03489949670250097, 0,
0.001217974870087876, 0.9993908270190958, 0.03487823687206265, 0,
0.03487823687206265, -0.03489949670250097, 0.9987820251299122, 0,
100, 100, 0, 1

Note that there is a 100 translate on both the X and Y axis so I can throughtly test my numbers.

I looks like the X and Y cosine and sine calculations are correct but something is not being calculated correctly after that. Nor is the calculation being applies to the translate values (I suspect I need to just research a bit to solve this). Hmm, as I look a little closer it looks like maybe some numbers are in the wrong spot ... but why?

Here is a pseudo version of the code I currently have

basematrix = [
[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[100, 100, 0, 1]
];
function RotateMatrix(y, x)
{
halfrot = 3.141592653589793 / 180; // pi divided by 180
xcos = cos(x * halfrot);
xsin = sin(x * halfrot);
ycos = cos(y * halfrot);
ysin = sin(y * halfrot);
ymatrix = [
[ycos, 0, -ysin, 0],
[0, 1, 0, 0],
[ysin, 0, ycos, 0],
[0, 0, 0, 1]
];
xmatrix = [
[1, 0, 0, 0],
[0, xcos, xsin, 0],
[0, -xsin, xcos, 0],
[0, 0, 0, 1]
];
calcmatrix = MatrixMultiply(ymatrix, basematrix);
calcmatrix = MatrixMultiply(xmatrix, calcmatrix);
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
//output calcmatrix[i][j]
}
}
}
function MatrixMultiply(matrixa, matrixb)
{
newmatrix = [];
for (i = 0; i < 4; ++i)
{
for (j = 0; j < 4; ++j)
{
newmatrix[i][j] = matrixa[i][0] * matrixb[0][j]
+ matrixa[i][1] * matrixb[1][j]
+ matrixa[i][2] * matrixb[2][j]
+ matrixa[i][3] * matrixb[3][j];
}
}
return newmatrix;
}

Maybe someone can see what I did wrong.

**Edited by Krik, 23 February 2013 - 05:08 AM.**