GeoTIFF import

[martinij]

Hello

Does anyone have experience with a workflow to get a GeoTIFF model into Archicad?

As Archicad does not import it directly some form of transformation is needed. Preferably by some kind of opensource software.

[Barry Kelly]

Do you have access to the software that creates the GeoTIFF file?

If so, can it save in any other format that Archicad can import.

Otherwise just Google 'GeoTIFF convertor' and you will get a bunch of stuff you might be able to use.

Barry.

[Erwin Edel]

Qgis offers the option to convert raster to XYZ and is opensource.

[martinij]

The GeoTIFF file comes from a web service, so I can't get any other format.

I think QGIS is the way to go as it supports the format well. The file is a large terrain, so exporting it to xyz will be quite heavy. I could thin the pointcloud in cloudcompare but the mesh generated in Archicad I fear will be to big.

The solution I think is to:

-> Import GeoTIFF to QGIS.

-> Set some kind of object with known coordinates so the terrain can be placed in Archicad.

-> Export some type of mesh from QGIS that can be imported in Archicad.

-> Import in Archicad and place to correct coordinates with the coordinate object we added.

Any experience or suggesjons regarding this workflow?

[Erwin Edel]

XYZ format is just a table of coordinates, you could maybe trim things in excel, to get a lower level of detail for your import. If you would add a row of repeating numbers or letters behind the coordinates, you can filter away half, two thirds, three quarters etc depending on how big the range is.

In terms of real world coordinates, I would grab these from a 2D source. Depending on where the project is located, it should also be possible to show these in Qgis and export a DXF.

I don't generally generate 3D terrain, just draft a simple mockup myself, but I find it quite easy to grab a 2D terrain drawing from Qgis from the Dutch sources, which are all open source.

[david_skogvold]

Don't have much experience with QGis, but I have used CloudCompare for similar things.

I would try bringing the GeoTIFF into CC, then subsampling it to a manageable amount of points. 2 million is definitely too much! I would try to keep the terrain as simple as possible, but try a few levels of detail to see what gets the job done without slowing it down too much.

CC can even filter points by various techniques - e.g. by distance to your building, so that faraway points are more aggressively deleted, or by amount of local detail, so that for a flat area you keep only a few points, while keeping more data in areas with more changing terrain.

Then you can either mesh the point cloud using 2.5D Delaunay Triangulation and export to STL for instance, or just export the simplified cloud as XYZ and bring into Archicad using Import->Points from Surveyor (XYZ) to generate the mesh.

David