====== Tips on Quaternions ======

Since 1.5, Foundation allows to mod Custom component and links it to a fbx (see Exemple02) 

Assuming the local axis Y of the building is vertical (most cases),
a way to compute the cosinus (named ''cosp'') and sinus (named ''sinp'') of the rotation angle of the building around the vertical is the following:

<code lua>
        local q = self:getOwner():getGlobalOrientation()
        local sinp = 2 * q[4] * q[2]
        local cosp = q[4] * q[4] - q[2] * q[2]
</code>

Note: 

1) You can check that ''cosp''*''cosp'' + ''sinp''*''sinp'' is near 1

2) This can be used, for instance, to convert a local direction on XZ plane (local coordonates for "translate"), to a global direction (global coordonates for "rayCast").