The direction determines the construction direction from the first ductwork point.
The direction of both clicked ductwork points will be shown.
Any angle can be used.
The main directions are:
horizontal:
000° - to the right on screen
090° - straight up on screen
180° - to the left on screen
270° - straight down on screen
vertical:
000° - horizontal construction
090° - vertical construction straight up
-90° - vertical construction straight down
tilted:
Ducts can be tilted around the horizontal axis.
e.g.: Cross-section example with roof slope:

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