How to create a TIN from 2D contours?

RE: How to create a TIN from 2D contours?

caddcop — Tue, 17 Dec 2019 19:31:02 GMT

There used to be a PDF, but I did find a video: https://www.youtube.com/watch?v=2JFqM3ba-8c

It is using a Pre-CE version of the product. I assume the workflow still exists, but might need different access points to the tools.

RE: How to create a TIN from 2D contours?

Marcus McConachie — Tue, 17 Dec 2019 19:21:14 GMT

Thanks for the reply. We received the DGN file from our client and it appears to be created from a shapefile. Not sure of their understanding of CAD so they likely thought this was what we wanted when requesting any surface information. I sent a request for the shapefile or lidar data used to create this DGN. I just wanted to research if there was another way to go about it that I wasn't familiar with. Thanks for the help!

RE: How to create a TIN from 2D contours?

caddcop — Tue, 17 Dec 2019 19:11:26 GMT

Well, the first thing I would do is see if the original LIDAR data is available. Building a surface from contours is fraught with issues. I always quote an old POB magazine article, "Contours are output, not input!" when this question gets raised. You will get significant flat areas based upon the image you posted.

I suspect that this data may have originated as a shape file as DGN elements do not generally have fields. There are posts or documents explaining how to get MicroStation to read a shape file and create 3D using a field value for the Z value, but these are for SHP files, not DGN files.

It's possible a VBA macro could be written, but that assumes the field can be exposed to the VB project, which may be a heavy lift.

RE: How to create a TIN from 2D contours?

Marcus McConachie — Tue, 17 Dec 2019 16:11:28 GMT