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Questions tagged [polyhedralsurface]

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Is there an established mapping from longitude-latitude to the face of a icosahedron?

Given a longitude and latitude, I’d like to map that to the face of an isocahedron projected onto the sphere (earth). The orientation of the isocahedron doesn’t matter so if there is a convenient or ...
gph's user avatar
  • 111
2 votes
0 answers
86 views

PostGIS tesselation invalidating polyhedralsurfaces

We are trying to visualise prefabricated concrete elements. These elements are exported in an ifc format. https://technical.buildingsmart.org/standards/ifc/ifc-formats/ We have already been able to ...
Glenn's user avatar
  • 29
1 vote
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How does the ISEA-projection work? Looking for a didactic algorithm description

Is it a direct projection on 20 faces or on 32 faces? Can I use PostGIS (with ISEA) to calculate and obtain cell-identifiers? For hexagons (like Uber H3) or for diamonds (like DGGRID's ISEA4D). The ...
Peter Krauss's user avatar
  • 2,304
2 votes
2 answers
287 views

ST_Tesselate on PolyhedralSurface is invalid : Polygon 0 is invalid: points don't lie in the same plane (and Is_Planar() only applies to polygons)

Using PostgreSQL 15/PostGIS 3.4.0, I am having troubles when tessellating some polyhedral surfaces. Indeed, I have a table where 99% of the surfaces are giving correct tessellation results, but few of ...
swiss_knight's user avatar
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1 vote
0 answers
94 views

Convert a LineString Z into a PolyhedralSurface in PostGIS

Follow up on this, if possible, how can I convert a geometry from a closed MULTILINESTRING Z into a POLYHEDRALSURFACE Z in PostGIS 3.3+? This question is the perfect opposite. Sample data: SELECT (...
swiss_knight's user avatar
  • 10.4k
2 votes
0 answers
185 views

Convert a PostGIS 2D polygon to a 3D Polyhedralsurface using C#

I'm trying to convert a 2D polygon into a 3D polyhedralsurface because i will use the surface to do a Intersect with other 3D geometries. The problem is when im trying to create the surface from a ...
Jacob Christiansen's user avatar
2 votes
0 answers
1k views

How to write Shapely polygons (or a multipolygon) to a PostGIS polyhedralsurface

Context In a Python script, I have a 3D square pyramid composed of 4 triangles (a list of 4 Shapely 3D polygons) that I need to store within a PostgreSQL database (+PostGIS). Here's what this pyramid ...
swiss_knight's user avatar
  • 10.4k