How can I model topography without contours and some places needed to be planer

I am trying to model a topography surface without countours. I first loft some contours so I get my first curvy surface but then some contours are flattened. So I am trying to make the curvy surface to become planer between the certain contours.

As I show in the image
the planar surface is the grey one. and the other curvy surface is the green one. I want beetween the black curves green one’s surface to be a planar surface but I want all of them seem a smooth surface. I want them to blend each other.

I will then send this surface to 3d printing.

How can I model it?

Hi -

You could try inserting points in the topography surface (InsertControlPoint) in the area where you need to surface to be flat. Then turn on the control points for that surface, select points along the grey surface and move those to the same elevation as the grey surface.

Another option would be to create contours from your topography surface (Contour) and then modify those contour curves to fit with the grey surface. Then extract the points from all curves and use MeshFromPoints (or the Delaunay Mesh component in Grasshopper or a plug-in such as Cockroach) to create a mesh from those points.