Springs nodes: Mesh.ToPolySurface

Hello everyone,

When I use the Topography.Mesh and Springs.MeshToPolySurface nodes to make a polysurface out of a topography revit just crashes without a warning.
The goal of the script is to create a family on a topography, within de perimeter of some model lines, with on the bottom the shape of the topography and on top it’s just a straight line on a certain level. It works on really simple topography’s (±10 points) but when the topo has more points (±450-500) to it. It just crashes Dynamo and Revit without warning.
I attached the script made in V2.1. I used springs nodes and clockworck package.

Dynamo script.dyn (101.4 KB)

Kind regards


The “Springs.MeshToPolySurface” node was a bit of an experiment of mine. It uses threading to run things in parallel for extra speed. While that worked fine on older versions of Dynamo and Revit, it seems something in the geometry kernel of either one changed over time and now that is not possible.

It seems to work as expected for some meshes and crashes for others:

I’ll simplify the node and make it single threaded for the next release.

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Hello Dimitar,

Thanks for your reply.
Do you already know when the next release is released?
And do you know a workaround for this until that time?

Just pushed the update. It will now run on a single thread by default, just like regular nodes. I You’ll still be able to override that and specify the number of threads, tho there’s a warning in the description of what may happen.

I also did some minor code cleanup and removed some generator code that might have been contributing to the instability. Do you mind sharing the topo that was causing the crash?

I used the Spring node to split a body by a topographie.

The topographie is complex due to many created points
result with a large body is a body where the topographie is printed into the body, the body has no volume
the same happens with a smaller body.
Do you know why this happens?

kind regards

Hello Dimitar,

I’m very sorry for my very late reaction but I couldn’t work at it for the past 6 months. I’m trying out your updated nodes and they seem to work on a small and simple toposurface but when I want to try them on a more complex topo they don’t work. Can you help me with this?

I attached the .rvt with the topo in a wetranser link and a screenshot where you can see that the output is null.


Had a quick look today. Seems that topo has something that dynamo’s geometry doesn’t agree with. I didn’t experience a crash but did get only a null return. What you could try to do is convert the mesh to a toolkit one and run a slight triangle reduction. That prioritizes any small triangles and gets rid of them. For example I try to do a ~10% reduction in the below image and get a mesh that is still very conformant to the original input:

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Hello Dimitar,

Thank you for your quick response. It works, with the topo I send you I can go to 99% detail level. 100% doesn’t work. But 99% is good enough for me.

hey @Dimitar_Venkov
I am doing the reverse where i have a bunch of polylines that i want to add as contours to create a surface.
do you have a node that does this?
if so, can you give me directions on how to download your package