Find slope or angle on a curved surface

Hi, Is there a way to find a slope to a curved surface?

I’ve been given a task to see if a curved roof will have a positive drainage with the current roof design. I’m concerned that the area (circled in blue in screenshot) has a slope less than 3%. Is there a way of finding this out in Dynamo?


thank you or helping me out.


If you evaluate coordinate systems at parameters you will get a CoordinateSystem that encodes the Normal as the Z and the Tangent as the Y (thats the slope)

Surface.DerivativesAtParameter should give you a pair of vectors tangential to the surface at the corresponding uv

thank guys. I’ll take a look at those nodes.

I was able to get the angle. Thank you!

But now I’m trying to assign a color to the panels. but all the panel color override is white. Why is not taking on the color from the color range i’ve specified?


thanks again,