Topography by points creates a wrong boundary

Hello guys,

when I create a topo surface in Dynamo via Topography by Points, it creates a different boundary. I searched a bit about that topic and I found it that it is possible in Revit 2020 to create via Polymesh facets and points.
My question: How can I get those vertices of polymesh?

I try to get points from a floor and create topography.

Thanks a lot!

Topo_von_Geschossdecke.dyn (38.1 KB)

I can create a sub region but it does not help me… I have to trim everything by hand after creating topo. It takes too much time :S

Hi @Deniz_Maral !
Do you reallly need a topogrphy ? If not you can get back the shape in Revit with a DirectShape or .sat file.

Unfortunately I need it as topography. In Site model elements are as slab shapes and it is very difficult to edit them. For example I need to demolish part of slab and for that I have to copy it > edit boundary > edit points and for second part same thing.

I can’t use “Parts” because it show its inneredges in plans and it seems very complicated for infrastructure.

Here is an example:

The yellow stands for demolished. So I have use topo to edit surface via “split surface” and demolish it.
Here I had to edit boundary per hand and deleted incorrect parts.

@Alban_de_Chasteigner has a node, that takes points and facets to create a topography but I can’t feed it with indices.

I would use dynamo to split the floor in two parts and phase them, and you will keep them i the right category.
And i think we can not control the way points are triangulated in Revit.
edit : i will try this node !

I have done it but it creates ugly lines:

you can hide it in Visibility/overides graphic

Nope, for parts you can’t hide them.

Hi Deniz,

Here is an example to use this custom node:
I used a dwg to get the points and indices.

Create Toposurface.dyn (15.6 KB)


Did you try :
1.edit boundary of the floor
2.copy the boundary
3.split topo
4.paste copied boundary

If you can Copy and Paste the boundary of floor, it Sounds to be a nice idea. I will let you know tomorrow about it.

Hello Alban,

Thank you very much for your efforts. My problem is to get that mesh geometry from floor. I got face vertex points but not indices.

Hello Alban,
I tried your node and your suggestion but I can’t create topo from triangulations and points. However I can create a mesh… Why is it like that?

Hi Deniz,

A PolymeshFacet represents a triangular piece. Each facet is defined by indices of three vertices of the polymesh.
I don’t think your list of PolymeshFacets is correct.

1 Like

Hello Alban,

thank you for your reply.

Their source is the same… Can be an iteration problem?

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You’re right.

Are there any points with the same x and y ?
Can you copy the python node of the custom node and read the error message ?

Warnung:IronPythonEvaluator.EvaluateIronPythonScript fehlgeschlagen.
Traceback (most recent call last):
  File "<string>", line 33, in <module>
Exception: There are invalid facets. Facets with more than two points with same x, y are not allowed.
Parameter name: facets

You are right. There are some points which have same X and Y. Should I prune duplicates?

Yes, it should work.
You will lose the points which are vertical to each other but the creation of topography is thus limited. (and less efficient than creating a mesh)