float xRotation[3][3];
float yRotation[3][3];
float zRotation[3][3];
float xVec[3] = {1.0, 0.0, 0.0};
float yVec[3] = {0.0, 1.0, 0.0};
float zVec[3] = {0.0, 0.0, 1.0};

VecRotToMat3( &xVec[0], yaw, xRotation);
VecRotToMat3( &yVec[0], pitch, yRotation);
VecRotToMat3( &zVec[0], roll, zRotation);

float xInv[3][3];
float yInv[3][3];
float zInv[3][3];
for (int i=0; i < 3; i++) {
	for (int j=0; j < 3; j++) {
		xInv[i][j] = xRotation[j][i];
	        yInv[i][j] = yRotation[j][i];
		zInv[i][j] = zRotation[j][i];
	}
}

MT_Matrix3x3 newOrient = MT_Matrix3x3(&xRotation[0][0]) * MT_Matrix3x3(&yRotation[0][0]) * MT_Matrix3x3(&zRotation[0][0]);
MT_Matrix3x3 invOrient = MT_Matrix3x3(&xInv[0][0]) * MT_Matrix3x3(&yInv[0][0]) * MT_Matrix3x3(&zInv[0][0]);

////ob->SetLocalOrientation(newOrient);
ob->SetLocalOrientation(invOrient);