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I have a shapefile GIS layer with several overlapping paths. They consist of geodetics/shortest path calculations from several origins to one destination. I want to visualise these paths as either as lines or buffered polygons in 3D, as this is not possible in 2D. Ideally, I would like to do this in GRASS GIS (I failed to do the same in R). ArcGIS Pro is able to do this via Feature to 3D By Attribute- see the example attached. ArcGIS

I did not manage to reproduce this in GRASS GIS. I have tried v.to.3d and v.extrude, but that does not yield the desired output (attached). Is GRASS capable of producing such visualisations at all? GRASS

EDIT: A quick test with simple 3D lines looks promising. Need to test tomorrow with full file.

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I tried with v.to.3d and it seems to work. I digitized a simple linestring with 4 partially overlapping features, and setup an attribute column with values for elev. I conmverted to 3D (v.to.3d) using the elev column. Then I displayed in a 3D Map Display window in GRASS. After setting "Z-exag" to 1000 and "Height" to 50 I got this image: enter image description here

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thank you! I tried again as well - and managed with v.to.3d. It did not work on my Windows work machine, but it does on my home Mac. I was not able to produce this with buffers, which would look a little nicer. ArcGIS handles buffers as 3D polygons, which GRASS GIS does not seem to able to do. enter image description here

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Smoother rendering can be achieved by converting all lines to tightly-spaced points and then convert the points to 3D (plot produced with m.nviz.image via R/rgrass).

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