Photogrammetry

[philipy]

We've touched on this subject a few times in the past, but I've just been pointed to an app/program/website that I've not come across before. It's called Polycam ( https://poly.cam/captures ) and has a free version as well as paid for. As usual the free version has limitations but interestingly, the paid for versions allow export direct to .stl and Sketchup, amongst other file formats.

It can handle stills ( minimum 20 pics) or video, so I nipped out into the garden this morning with SWMBO's iphone and walked round a garden ornament 3 times, uploaded the video to the Polycam site and half an hour later downloaded this video. It is taken from the interactive file the site produces and with that you can zoom in, flip it round, and generally view it in 3-d, etc. (BTW, the brown floaty bits are plant seed heads but the stalks didn't register!)

Apparently recent iphones have built-in LIDAR and it can also produce constructions from that and there are other things it can do.

I'm very impressed so far!

[drewzero1]

Impressive! I might have to give it a go. Been thinking a lot about photogrammetry since watching someone on youtube recreate a church in Connecticut that collapsed a few weeks ago. Might be interesting to try creating models to print from a tool like this... after removing the floating seed heads, of course!

[philipy]

I've had another play this morning.
Firstly after a few emails from Polycam trying to prod me into paying $99.99 for an annual subscription, this morning I had one offering me a 50% discount, so was beginning to wonder if that might be worth it. Then I noticed that there is a 7day free trial on the annual subscription, so I signed up for that.

Took a video of this white metal Victorian postman, uploaded and processed it and then exported the stl and loaded that into Cura. This shows :
1) Third from the left, the original figure with the Polycan exported stl alongside to the right. He is 97mm tall inc the base (which wants trimming off of course.)
2) Two from the left, the same file exported as a .dae and then imported into Sketchup, the base trimmed off and re-exported as an stl, in Cura.

It isn't perfect but some of the blebs are due to the chips in the paintwork, and I suspect the quality would improve with a longer video giving more data to reconstruct.

Screenshot 2024-02-07 13.10.45.png (1.75 MiB) Viewed 189 times

It's not bad, but not as good as I had hoped, and at the mo I'm not sure it's worth $50 a year and certainly not $100!
I think the basic issue is that programs like this are not intended for very small stuff like our figures etc. If it was a 12"/ft castle, fr'instance, small blebs wouldn''t notice!

[drewzero1]

Looks about on par with most of the scanned objects I've seen on Thingiverse et al... I've been contemplating trying it out for scanning 1:1 scale objects to shrink down to scale. I wonder if it'd be any good for modeling real people, if they can hold their pose for long enough for a decent capture?