# Spot slope

Hi all,

Does anyone know how the orientation of the slope vector is calculated ?

With a triangular ground formed of 3 slopes like this:

I can calculate the value with dynamo but not the drawing of the spot slope !

Thanks for all

It’s perpendicular to the topography isocurves. Here some examples:

With 2 points at level 0:

With 2 points at level 2:

With points at level 0,1,2 (your case):

Indeed you can see that the direction of the vector depends on its position:

For my case, It’s not perpendicular to the topography isocurves:

If you drew the green line, then it might be that you didn’t draw it correctly.
I might be wrong, but if the top point is 3, the second is 2.80 and last is 2.30, I doubt that the isocurve is in the middle, it should be lower.

Which kind of objects is it? If is a toposurface, you can show the isocurves at distance 0.1 for example, and post a screenshot. Also I don’t understand if it’s a 3d view or a plan view.

it is a 3D view in the first image and a 2D view in the second
This is a floor, I calculated the iso curve with dynamo but it doesn’t match your drawing, nor the green line by the way
Please look this rvt file (2018)
Pente de toit (Extract).rvt (1.7 MB)

I recreated a topography on top of your floor with exactly the same 3 points, and as you can see the isocurves (at distance 0.1 m) are perpendicular to the arrow.

I guess you calculated wrong the isocurves with Dynamo (you can still see your green line)

So cool ! thanks for all…