Question

Creating a DEM from points

  • 17 July 2019
  • 3 replies
  • 33 views
S
Badge

Hello,

I have a dgn file containing a 3D model of a ground surface. From the dgn I created a 3D polygon shapefile, extracted the vertices to points and assigned Z values to the points. I would like to interpolate between the points I extracted to create a DEM. This process works well in ArcGIS, using the Create TIN tool and I'm able to create a DEM raster that closely resembles the original 3D model. I've been trying to replicate this process in FME but I can't seem to generate a TIN similar to that of the original model. I've tried using TINgenerator, DEMgenerator, RasterDEMGenerator and Surfacemodeller. With all of these methods it appears to interpolate a surface but the faces are missing (looks like a greenhouse with the glass taken out). Or the interpolation is so course that it creates huge triangles, which is something that the Create TIN tool in ArcGIS appears to overcome.

 

 

Is there away that I can generate a TIN with solid faces and a higher resolution of interpolation that I can then export to raster?

 

thank you for your time.

3 replies

sigtill
Rank
Badge +21

Hi @scarecrow

Take the 3D model through the PointCloudCombiner and then create the Surface

"Point and linear features will be converted point for point. Polygonal, donut, surface and solid features will be converted into a grid of points lying inside the area on the 3D plane represented by the area’s calculated normal. Any existing component values stored as measures or attributes can be preserved as components."

The real SigTill
S
Badge

Hi @sigtill

 

Thank you for your reply. I've tried the method you describe and it does simplify the process I was using before. However, I'm still not able to generate a solid surface (just a series of open triangles).

sigtill
Rank
Badge +21

Adding a Facereplacer and MeshBuilder after the Triangles? You can also look into the BRepSolidBoundaryCreator

The real SigTill

Reply


Community Stats

28,661
Posts
109,324
Replies
36,528
Members
Terms & ConditionsCookie settings
A product of
Safe Software respectfully acknowledges that we live, learn and work on the traditional and unceded territories of the Kwantlen, Katzie, and Semiahmoo First Nations.