How to use this type of data
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Imported points data using delauney methods will 'melt' vertical objects as it needs to triangulate facets... some of which won't be what you'll expect.
If you can filter out the buildings in CAD and then export the 'site' mesh points that gives better results...
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Is there other method of triangulating which would be better for buildings.... as I am after buildings really?
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I managed to do it but using SU8 on the Mac side. SU7 has no such problem on Vista. Kind of interesting.
It took nearly 3 hours and SU did not go non-responsive in both instances. Coffee was good and cake very moist.
The mesh turn out in not very usable state as buildings look like they are melting....maybe good for some Sci-Fi environment.....this Lidar data is kind of disappointing.
The file had 40406 points ... It created 80000 triangles. -
Not that I know of - the problem is working out which points make a facet.
IF the points are in a file and they are always arranged in sets so that they define a triangular face - like in many OBJ files - then it's much easier to replicate those facets in a SKP...
Unfortunately, the DXF data gets muddled once it's imported.
Are there any other file formats like csv/tsv/txt you can get the points data in?
These could be read into a SKP much more readily that a DXF... -
I see....I need to check if there are any other file types available.
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Hmmm... It does not appear to be available. I was wondering if maybe this is all driven for Autodesk Map
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You could try meshlab http://www.meshlab.org/ http://meshlabstuff.blogspot.com/
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Thanks Notareal but as far as I know Meshlab does not import .dxf/dwg.
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What does it export? If it will take any other sort of standard file type - csv, obj, anything?, maybe we can write an exporter for it.
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@sepo said:
Thanks Notareal but as far as I know Meshlab does not import .dxf/dwg.
You don't get the LiDAR data in any other format? That unfortunate as meshlab is indeed a very good program to handle point clouds.
Meshlab
import:PLY, STL, OFF, OBJ, 3DS, COLLADA, PTX, V3D, PTS, APTS, XYZ, GTS, TRI, ASC, X3D, X3DV, VRML, ALN
export:PLY, STL, OFF, OBJ, 3DS, COLLADA, VRML, DXF, GTS, U3D, IDTF, X3D
Point Clouds support. Now 3D files that are composed only by points are well supported in PLY and OBJ format. -
Collada is essentialy an xml file - just plain text. It would be relatively easy to export a collada file with the point could data, if it was known what collada elements they need. SketchUp might even be able to do it natively with their collada exporter.
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I supose I could export .dxf to collada and try it that way....
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@chris fullmer said:
What does it export? If it will take any other sort of standard file type - csv, obj, anything?, maybe we can write an exporter for it.
Chris
This is website I wanted to get Lidar data from .... http://www.stanfords.co.uk/Business-Mapping/BM/Products/LiDAR_BM-LIDAR.htm -
Any text format file [even DXF] can be parsed and the points extracted in order.
If we know that that say every three of them make a triangular facet we can use that to add geometry.
It'd be a pain in the proverbial to parse a DXF file [it can be done! e.g. I extract 'text' in my dxf-text-importer tool] but other types like OBJ, CSV etc can be readily parsed and used... [DAE doesn't seem to support raw 'points', just facets]
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Sepo, I have not used it yet but I have installed the tgi3d plugin. I suspect it would handle the stereo pairs quite nicely. This is exactly what their PhotoScan product is supposed to do. Basically you take two or more photos of a surface or surfaces from widely separated areas. Then you mark corresponding points in the photo sets and the software uses these control points to reverse engineer the 3D shape of the surface.
I have also figured out a LIDAR like system of establishing surface control points on small stationary object that does not have strong features to compare photographically. I will post my experiments as time allows. Will be heading to Thailand for a month so it might be a while before I can test the system.
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@roger said:
Sepo, I have not used it yet but I have installed the tgi3d plugin. I suspect it would handle the stereo pairs quite nicely. This is exactly what their PhotoScan product is supposed to do. Basically you take two or more photos of a surface or surfaces from widely separated areas. Then you mark corresponding points in the photo sets and the software uses these control points to reverse engineer the 3D shape of the surface.
I have also figured out a LIDAR like system of establishing surface control points on small stationary object that does not have strong features to compare photographically. I will post my experiments as time allows. Will be heading to Thailand for a month so it might be a while before I can test the system.
That would be quite interesting. Have you actually tried PhotoScan with tgi3d? I was wondering which other software people would use to create models from 2 photos shot with time delay.
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@tig said:
Any text format file [even DXF] can be parsed and the points extracted in order.
If we know that that say every three of them make a triangular facet we can use that to add geometry.
It'd be a pain in the proverbial to parse a DXF file [it can be done! e.g. I extract 'text' in my dxf-text-importer tool] but other types like OBJ, CSV etc can be readily parsed and used... [DAE doesn't seem to support raw 'points', just facets]
OK so no joy there as well.
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@unknownuser said:
That would be quite interesting. Have you actually tried PhotoScan with tgi3d? I was wondering which other software people would use to create models from 2 photos shot with time delay.
Will jump on the learning curve today. And time delay is not strictly necessary if two or more synched cameras are used. I plan to try multiple linked cameras at 4,000th of a second to freeze an athlete in motion.
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Seriously Roger, I'm going to down to AZ and follow you around for a few days. You always have some cool camera project cooking in the background.
EDIT:
ok, I imported the example dxf and see the point cloud. Very interesting. What are you expecting differently than you achieved previously? The triangulated TIN looks pretty good to me.
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@chris fullmer said:
EDIT:
ok, I imported the example dxf and see the point cloud. Very interesting. What are you expecting differently than you achieved previously? The triangulated TIN looks pretty good to me.
Well the TIN is unusable as the buildings (in my case) look like melting cakes.
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