Talk:Destinations/Advanced Outdoors Photogrammetry

Hi mate,

Excellent work. I really enjoyed your destination too. I'm following a similar workflow but am restricted to Photoscan, for scanning, and Blender, for modelling. I'm testing a simple scene with only foreground geometry, I want to project all other image data onto a skybox and perhaps a ground plane.

I'm exporting a completed mesh from Photoscan into blender, building additional geometry (skybox and ground plane) and reimporting with the same xyz coordinates back into Photoscan for texture generation.

While some of the surrounding photo data does project onto the sphere, uncovered areas remain black. I was wondering if I'm missing something during the uv generation stage in Blender. Prior to having actual texture materials, are you suggesting I can generate a uv map that will "spherize" textures later projected onto it?

I understand and appreciate that my software is different to yours. I suppose I'm just a bit lost when it comes to setting up uvs on the skybox / other geometry before reimporting. I'm not familiar with the term "relaxing" the UV.

Any help would be appreciated.

Cheers and, as I said earlier, awesome work!

I haven't used Blender all that much, but essentially what you'll want to do is create a new material for the skydome, then add a basic UV map for PhotoScan to project on to. I've added a screenshot to the article showing skydome UVs for my scene in Modo.

Technically, you could use just about any UV projection that gives non-overlapping results, but the aim is to get something that minimises stretching and gives something easy to edit in Photoshop or similar. (The Blender equivalent to Modo's 'UV relax' feature seems to be 'minimise stretch'.) I found the planar-projection-plus-relaxation is really quick to set up and gives a pleasantly editable circle, but opinions may vary. (Working with the circular horizon can get ... interesting?)

Cylindrical and spherical projections could work, but you'll get tricky seams at various points.

Hope that's of some use! I'm really interested to see what everyone comes up with. —Cargo Cult _{(info, talk)} 23:51, 19 July 2016 (UTC)

Thanks, thats a great pic. Your skydome fills in really nicely. Did you take panoramaic pictures of the sky specifically to help fill in that data?

Super-wide lens as used for all the other shots, aimed a bit above the horizon for some shots making up a really rough panorama - so including a fair amount of land etc. for alignment purposes. It doesn't cover the full sky (there's a gap right above) but with PhotoScan's interpolation and a bit of Photoshopping, the results are pretty seamless. Good luck! —Cargo Cult _{(info, talk)} 20:42, 20 July 2016 (UTC)