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Photogrammetry workflows

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Hi all,

I recently decided I'd dabble in some photogrammetry with our office drone and have been really quite surprised at the quality of the results I managed to achieve. The only downside is that the meshes that are generated are (as you might expect) incredibly uneconomical when it comes to triangles, and the texture atlases are wild - unusable if I wanted to edit them in say photoshop, for example.

I'm currently using meshroom to create the models, but am not averse to buying something else if it allows us to produce better meshes and textures, so my first question would be what software would you recommend?

Secondly, assuming the other software churns out fairly similar stuff, how would you suggest editing these meshes so they're a bit less unwieldy. I've tried the ProOptimizer modifier in 3ds max, but that seems to just hang forever without doing anything. I've also tried the new retopology tools in max, but again the same result; it just hangs.

Any suggestions as to how to clean up the meshes, and bake the textures into a useable form would be much appreciated.

Many thanks,


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For geometry cleanup I usually take the model into zbrush, do an automatic retopology and then re project. The retopology lets you select polygon count which is nice, so you can select 15,000 polygons and let it do its work takes a few seconds and its all quads. The model gets a bit rounded in detail areas so the re project then allows you to sharpen those corners, again automatically. The whole thing takes maybe 30 seconds and you have a really clean model to export back to obj. 

For the texture you can also do an automatic flat unwrap in zbrush, although I prefer to use rizom. This way you can just quickly create a few edge loops and flat unwrap, remove distortion get the texel density consistent and auto pack the unwrap nicely into the 0-1 space. This takes maybe 10-15 minutes for a moderately complex model. Once you have the new uv layout on your obj file you can import this into your photogrammetry software and then re project the texture from the old uv to the new uv.

Once you have done this it should look the same as before but with clean quads, clean uv and from there you can just do any cleanup on the textures in substance painter. 

The main thing is having a good lighting setup, this artist (LuckyFox) has a great result using a light tent and some polarizing filters to capture the albedo as clean as possible for creating the pbr textures. I advise checking it out hes also kind enough to chat about specifics if you get stuck.


Edited by James Vella
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  • 3 weeks later...

Hi James,

Apologies for the delayed reply. Your reply was most helpful.

I think one of the things we're struggling with at the moment is that our photogrammetry isn't of small/individual objects, it's of entire buildings/sites - so trying to get a decent topology/textures on this is proving onerous. Being new to ZBrush (still using the trial at the moment) it's feeling like an uphill battle; the navigation of the viewport is arguably the worst I've ever used in any 3D software - is there a way to change this?

I don't suppose you've used ZBrush on a whole building/site?

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  • 2 weeks later...

Hey Chris,

Sorry for the late reply. 

I haven't done anything as large as a building for production, I have done a few drone tests for landscapes (parks etc) but the quality was sub-par, good for distance that was about it so I can totally understand your texture and topology issue. Doing something like this would probably require lots of close up shots and then getting these to line up with the overall model would be a lot of manual work with linking points which sounds like a nightmare. Also the fact buildings are quite rectangular around the silhouette and then the detailed window frames might be quite an issue to get something desirable.

My thoughts would be to model the base structure using boxes/basic shapes (under the point cloud mesh) then project the texture once its back in the photogrammetry software. Sounds like a bit of hit and miss though, probably lots of time required on R&D for something like this if you need it clean. This is just an idea so sorry no actual advice from me on this.

Hah, yeah Zbrush interface is not something I enjoy either, its totally wild and there is not much you can do about it. From my experience I just learned the tools I needed (about 20 in total) and then had to youtube my way around everything else until I was comfortable enough to get the job done in the most efficient manner. From some of the youtube videos I watched there is quite a lot of power in the way the UI has been designed for those who are accustom to it,  it just requires a shift in thinking and after awhile the tools can be quite robust, some of which I wish were available in 3dsmax etc. But I'm not a professional sculptor so unfortunately I don't think ill ever grasp it for its full potential. 

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