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Topic: point cloud 3D potential

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Bellerophon2200 (Over 1 year ago)
Hi, I'm new to photosynthing.  I mean, I just downloaded it yesterday.  I noticed that 100% synthy, synths had very accurate point clouds.  

I wonder if this same method could be used to import .obj files into a 3D rendering program like Blender?  If one could export the geometry, then making 3D buildings and detailed cartography could be really easy!  There is not much need to do such a thing, because synth has texture and geometry in one.  Though, it could allow editing of the information.  Just an idea.
Nathanael (Over 1 year ago)
Right on. =)

Just a note: 100% synthy really only means that all the photos linked to each other. I could make a 12 photo synth where I stand in one place and rotate 360 degrees around my position and provide enough overlap for all the images to match their neighbors, but the point cloud is going to be pretty awful because there will be practically no parallax (foreground moving against background and sides of things becoming visible as you move sideways while facing the front of a building). Parallax is what Photosynth needs to discover the positions of unique patches of texture, so moving around and making sure that you have enough photos moving from one thing to the next is what is critical for great pointclouds.

Still, pointclouds aren't everything and sometimes a 100% synthy synth with only 20 photos and not much of a pointcloud can be incredibly satisfying: 
http://photosynth.net/view.aspx?cid=67049f02-baf7-481f-b516-a47dc187a517
Nathanael (Over 1 year ago)
Getting back to what you were saying, though, here are some articles and videos that you might enjoy: 

A brief history of exporting pointclouds:
http://ch9.ms/BDPM

Bigger Pointclouds:
http://www.cs.washington.edu/homes/snavely/projects/skeletalset/
http://grail.cs.washington.edu/rome/

Dense Pointclouds: 
http://video-jsoe.ucsd.edu/asx/AguerayArcas.asx
http://www.youtube.com/watch?v=6cnP8FqRoPI

Beyond Pointclouds:
Meshes: http://grail.cs.washington.edu/projects/mvscpc/
Oriented Patches: http://grail.cs.washington.edu/rome/dense.html
Oriented Patches: http://www.cs.washington.edu/homes/furukawa/ (Towards Internet-scale Multi-view Stereo)
Nathanael (Over 1 year ago)
It's also worth noting that automated photogrammetry is behind the generation of 3D buildings from the Bird's Eye photography in the older version of Bing Maps 3D (and I expect in the new Silverlight version as well, although the results are not as observable because of Silverlight 3's lack of real 3D support) as well as being used in Google Earth where hand created models from Sketchup are not available.

Other interesting services are things like ARC3D. You can check it out here: 
http://homes.esat.kuleuven.be/~visit3d/webservice/v2/

If you just made it through all those links, there's a good chance you might appreciate all of the links that I've collected in an Excel spreadsheet for your sorting and learning pleasure here: 
http://cid-0ef7a30c1e7b926c.skydrive.live.com/browse.aspx/Photosynth
Bellerophon2200 (Over 1 year ago)
Nathanael,
    Thank you so much for all the links you gave me!  It's like a crash course in rendering from synth. lol.  I never expected in my dreams to find such support on this topic, and in such a short amount of time.  
I actually followed a link http://ch9.ms/BDPM>http://www.youtube.com/watch?v=TuHJUS2olyc>http://antiverse.isa-geek.net/bintoply/>http://pspcexporter.codeplex.com/

and I got a coded EXTRACTOR!  How great is that!?  Now I have a point cloud in mesh lab of a tower in compangnon.

I plan to add UV texture in BLENDER and then export to fallout 3, so if anyone video games on PC then this could be an extremely easy way to create and import a .NIF.  Then entire virtual worlds could be created with little effort and time, and could be experienced through the game engine.

Thanks again Nathanael!!!  I'll see how far I can go with this, and I'll try to update this forum and try to put something on the NEXUS forum once I can make a streamlined process.
Nathanael (Over 1 year ago)
I had hoped that you would read the first comment on that Channel 9 story, since I linked to Christoph's exporter there, but I'm glad you found it in the end anyhow. =)

There are a few other useful links in that comment as well like others' workflows for conversions to meshes etc.

I'll look forward to seeing your results.
Shalihmysynth (Over 1 year ago)
nice discussion
Bellerophon2200 (Over 1 year ago)
UPDATE:  Mission failed...well...sort of X_x

After working on it for a while, I've found that point cloud meshing is possible, and easy, but not feasible for those without a reverse engineering/CAD program.

I tried using Meshlab for a point cloud with the method outlined in this forum, but obtained a mesh lacking detail.
LINK: http://meshlabstuff.blogspot.com/2009/09/meshing-point-clouds.html

I also tried using a Blender plug-in, but it wasn't exactly scalable.
I used a cloud of >364,000 vertices; which means >120,000 polys/>81,000 quads.  I have an i7 at 2.67 Ghz and, due to absence of hyperthreading and sheer number of verts, the program would never render.
LINK:  http://blenderartists.org/forum/showthread.php?t=144504

Finally, I tried using VRmesh, with great success.  VRmesh used it's own algorithms for sampling, meshing and cleaning.  It was completely scalable and the obvious solution, but, it was $800 for a single user family license (educational license)
Bellerophon2200 (Over 1 year ago)
CONTINUED:

Conclusion:
In order to make a good mesh from a point cloud you need an expensive meshing software such as VRmesh, pointools, rhino, etc.  My search does not end here though.  I'm going to keep looking for alternatives for fast and non-propreitary self point cloud meshing.
dpm11 (Over 1 year ago)
Hey Bellerophon2200,

I recently downloaded the demo version of VRMesh Studio 5.0 but haven't had any luck with it. I've been using Synth Export to extract the dot clouds at ply and wrl. I can't seem to open either in VRMesh studio. It wants a .vrg but I'm not exactly sure how to extract the point cloud into that.
Please let me know what I'm doing wrong and where I should go once I can load the correct file type. I'm assuming just clicking cloud->mesh and selecting the appropriate noise level but let me know if I'm wrong.

Thanks
dpm11 (Over 1 year ago)
Nevermind. I just needed to go to import and choose the correct extension instead of using open file.
I'm wondering what features you found really great with the program. So far, my meshes have only come out to Meshlab level (although I need to do a lot of manual cleaning up in Meshlab).
Any suggestions?
Bellerophon2200 (Over 1 year ago)
@dpm11

The only thing that was better about VRmesh, was that it used hyperthreading and was more forgiving with high polys, because it wouldn't crash unexpectedly like meshlab.

you might also want to try looking at this:  www.vi3dim.com  though, I have had very little luck with it so far.
Nathanael (Over 1 year ago)
Anyone interested in this thread should also visit a new photogrammetry forum that Ólafur Haraldsson started: http://pgrammetry.com/forum/

Please don't stop posting here, though. I just wanted to make people aware of another resource.
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