topic Re: Exported LandXML file from C3D not propertly converting into Infraworks in InfraWorks Forum

Exported LandXML file from C3D not propertly converting into Infraworks

ngjangZWT64 — Sat, 15 Nov 2025 00:38:27 GMT

I'm really new to C3D and I tried exporting a surface as a LandXML file, which shows a dip in the terrain on Object Viewer and contour/triangle lines, however, it doesn't show up on Infraworks when uploaded there. There are just a few really buggy looking lines. I was wondering what I am doing wrong??

Re: Exported LandXML file from C3D not propertly converting into Infraworks

Todd_Rogers — Mon, 17 Nov 2025 13:52:48 GMT

Try using IMX. It's on the Output tab in Civil 3D. Also, keep in mind, TIN surfaces are not great surfaces, and you will have anomalies in surfaces in InfraWorks. It just is what it is. To fix the issue in InfraWorks, draw a coverage area around that area, right-click on it, and choose Shape Terrain. That will smooth out the surface in that area.

Re: Exported LandXML file from C3D not propertly converting into Infraworks

jpopePXAJJ — Tue, 25 Nov 2025 15:26:13 GMT

Did you create your Infraworks model using the model builder? If so, do you still have the topography visible from that model generation? If you do, that original surface might be interfering with the hole that you created in your LandXML file. Make sure your imported surface is the only one visible (light bulb icon) and/or it's at the top of the Ground Surface list in the Surface Layers window in Infraworks. I don't usually have any issues with LandXML surfaces from Civil 3D.

Jeffrey Pope

Civil CAD Manager - Magnusson Klemencic Associates

Re: Exported LandXML file from C3D not propertly converting into Infraworks

Karsten.Saenger — Tue, 02 Dec 2025 07:56:58 GMT

Hi @ngjangZWT64 ,

there are quite a few thin and long triangles in the terrain. It looks better in the wireframe image. What happened with them compared to the shaded image?

Try to reduce the triangles in Civil 3D, for example, reduce the number of PVIs in the lines used in the grading.

Regards,
Karsten.