matrix multiplication
private function matrixMultiply(matrixA:Array, matrixB:Array):Array
{
var result:Array = new Array();
result[0] = matrixA[0] * matrixB[0][0] +
matrixA[1] * matrixB[1][0] +
matrixA[2] * matrixB[2][0];
result[1] = matrixA[0] * matrixB[0][1] +
matrixA[1] * matrixB[1][1] +
matrixA[2] * matrixB[2][1];
result[2] = matrixA[0] * matrixB[0][2] +
matrixA[1] * matrixB[1][2] +
matrixA[2] * matrixB[2][2];
return result;
}