Create Toposurface from Import - Contour Lines

[Anonymous]

We have a multi-project site that is halfway through development and I have been tasked with creating the 3D siteplan for rendering purposes, including walkthroughs of the entire site. As it is still in development, it is changing frequently, so I am attempting to create a 3D cad file with contour lines we can use to easily control/update the surface as needed. As much as I would love to just get the TIN from the civil engineer, that is not currently an option. The current method works extremely well for our purposes... except when it doesn't.

The problem is that Revit seems to place points at MOST of the polyline vertices, but decides (arbitrarily?) to ignore some occasionally in key locations. Adding vertices does not change this behavior in these locations. Does anyone know how Revit chooses where to put points when creating the surface, if not at each vertex? And/or does anyone know of a way to force points at the desired locations without manually adding them afterward?

[joe_keogh]

Hi @Anonymous 

That seems a bit strange, is it possible for you to share a screen shot of the the topo you are trying to make and the bits Revit is missing.  Better still if you share the contour file we can test.

[Anonymous]

I was trying to figure out the best way to show this - here's a screenshot of the polylines in the contour file compared to the points in the revit file, with some missing points circled in red. It's worth noting that this happens in a few other select areas as well and has persisted despite various reloadings and new topos, so I'm guessing it's an algorithm thing of some sort? Anyway I've attached the contour file as well. Thanks!

[ToanDN]

How about using divide or measure command in AutoCAD to place points along the polylines, dataextraction the points to a CSV to generate the topography?

[Anonymous]

I was under the impression that Revit did not read points out of a cad file like that. Has it changed recently?

[barthbradley]

That's something you would need to do manually (e.g. "force" additional points to create more triangulated geometry). I can see that that would not be practical if the Toposurface is being "updated" (e.g. re-created) through the life of the Project.  As for how the actual algorithm works: got me.  I'll bet you someone from the Revit API Forum can answer this question intelligibly though.   

[joe_keogh]

I have had a few goes at it, and getting the same results you are.  I have tried exploding, and tried splitting the file into 2 (North/South)

Are you creating the file in AutoCAD or Civil 3D??

[Anonymous]

I am using autocad - I probably have access to civil 3D but it's not something we use or that I have any experience using.

[ToanDN]

Attached is an example based on your CAD.  I use DIVIDE and didn't specify a lot of points so the result maybe rough.  You could use DIVIDE and specify more points on the more complex/important lines, or use MEASURE and specify a distance to get a better result.

[Anonymous]

Intriguing. Not quite what I'm after, but if I can't get that this would be a better way than having to place every point manually. Thanks!