Working with Slab Shape Floors in Revit can be a tedious process. There are two options for creating sloping Floors: use a Slope Arrow for a single slope across the entire Floor or convert the Floor to a Slab Shape and modify its points and edges. Unfortunately, there is no way to combine these two methods in the Revit UI.
Ideally, you would be able to start with a Floor, give it a single slope, and then convert it into a Slab Shape. But of course, this is possible with the Revit API and can even be done with Dynamo.
One of the very first Dynamo blog posts I read demonstrated how to place an adaptive fence component so that it would follow Topo. At the time, I thought it was an interesting concept, but not overly useful since I typically use non-adaptive fence components and fences will frequently step (instead of slope) with grade change.
However, not all fences are stepped, and I recently decided to take a look at trying the same concept on a non-adaptive fence. It is quite a bit more complicated than the adaptive version, but there are several reasons why you might not use an adaptive fence component and the concept can also be used to place a stepped fence.
If you have to model an existing landscape in Revit, Dynamo can be an excellent tool to automate that process. Not only can you quickly create existing hardscape (that follows Topo), but you can also automatically place and size existing trees using survey data.
In fact, you can use this process to automatically place any element that exists in your AutoCAD survey as a block.
Topography in Revit can be tricky to manage for a number of reasons, but I would say the most limiting factor is that you can only input points (meaning, you cannot input contour lines or a mesh). If you do use a mesh or 3D lines to create a Topo, Revit simply takes the points from those elements and gives you no control in the generated mesh and contours.
This can be fairly frustrating, particularly if you are accustomed to Civil 3D, where you have control over these elements. Unfortunately, this is an issue that is hard-coded into Revit Topos, so until Autodesk decides to fix the Revit surface engine there isn’t much you can do (besides use other elements, which can be a partial solution).
Once the Topo is generated, you can extract the contour lines and underlying mesh elements by exporting a 3D view to dwg. And with Dynamo, you can extract all three Topo elements (points, contour lines, and mesh) entirely within Revit.