In OpenBuildings using any expression if any negative angle value was calculated that value does not reflect in the geometry. To reflect that value in geometry you need to follow the steps mentioned below,
If the ‘Negative Angle’ value needs to reflect the in the geometry then the negative value can be expressed using this expression,
There you require another variable to choose when to use ‘Positive Angle’ and ‘Negative Angle’ values. The name of the Variable will be the ‘Angle Condition’ and this will be the expression used for it,