Keyboard Photogrammetry

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snacksthecat
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13 Mar 2020, 00:10

SneakyRobb wrote:
12 Mar 2020, 14:22
Zbrush looks interesting. From my attempts there sometimes are little "hanger" pieces that are hard to remove. So that is cool and looks like it could help.

Also I like your scans of switches. I've been trying to figure out realitycapture for a few days. Not sure what I'm doing wrong but hopefully I can figure it out in the next 2 days, otherwise Ill post in the tutorial thread my issues.
Very cool. I like working in RealityCapture a lot. Whenever something turns out poorly in Metashape, that's my go-to. It produces really good looking meshes and textures. The only warning I have is don't get carried away with control points. I've spent hours upon hours carefully placing control points to help the app with alignment, to no avail. I've read people having success with them by setting very high weighting on each point (e.g. 200 vs. 10). But I myself just haven't been able to effectively use control points for alignment. If I put an hour of work in and the photos still don't align, I should just give up and move on.

I've recently figured out that you can do alignment in Metashape and export to .out (bundler) format. Then import the .out file into RealityCapture. But I'm not sure if the photos should be exported from Metashape as undistorted or not, and haven't had enough time to fiddle with it yet.

I also just got a digital drawing tablet so I can do touch-ups in Zbrush. So I guess you can call me snacksthedigitalartist now.

The next board I scanned is my indie SSK. So far its coming along really nicely but I'm also trying to test out different things to see how it effects the finished product. The main piece I'm adding to my workflow goes like this:
  • Run photogrammetry and generate mesh in Metashape
  • Export from Metashape, import to Zbrush, clean up bumpiness, holes, etc.
  • Remesh, unwrap, export from Zbrush. Import back into Metashape
  • Decimate down to ~250,000 faces
  • Run "Refine Mesh" tool (high settings)
When running "Refine Mesh", a few things to point out. First, I'm decimating down to a lower poly count because this procedure subdivides the mesh 3 or 4 times so if you don't do this, you end up with an insane number of faces. I'm also running it on "High" rather than "Ultra High" because apparently my PC doesn't have enough video memory for ultra. But that's probably okay because, lastly, I'm disabling all photos except for the ~150 closeup photos I took.

I'll go into detail more later but recently I've found I can really improve the quality of the mesh by taking one set of photos with the whole object in frame, mostly to capture the general structure. Then I come in with a zoomier lens and take some closeup pictures. The pictures from set #1 get the full shape of the object and provide a reference point for getting the camera positions from set #2.

It's a bit of a hassle because you end up taking a ton of photos this way. I'd also like to experiment with markers (like matt3o suggested in the tutorial thread). It might make my life a whole lot easier aligning the "general shape" set of images.

Oh and I've learned one more thing. I've been generating my meshes with way too many target faces. I basically have been allowing it to produce as many faces as needed. I've found that by reducing the target face count (something around like 750,000 - 1,000,000), I get a much prettier model. Fewer craters, bumpiness, etc.

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snacksthecat
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13 Mar 2020, 02:22

And it's done! I think I've taken this one as far as I can go with it, without taking more pictures. This one I wish the I'd set my white balance correctly (had it leftover from a different set). So it turned out a little bit green/yellow. I adjusted the sketchfab settings to compensate for this. Already went into some detail about what I've done differently these past few scans so not much more to say.

https://skfb.ly/6QSTH
Image

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SneakyRobb
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13 Mar 2020, 22:24

snacksthecat wrote:
13 Mar 2020, 02:22
And it's done! I think I've taken this one as far as I can go with it, without taking more pictures. This one I wish the I'd set my white balance correctly (had it leftover from a different set). So it turned out a little bit green/yellow. I adjusted the sketchfab settings to compensate for this. Already went into some detail about what I've done differently these past few scans so not much more to say.

https://skfb.ly/6QSTH
Image
Hi, that is a gorgeous model!

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snacksthecat
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13 Mar 2020, 23:20

SneakyRobb wrote:
13 Mar 2020, 22:24
Hi, that is a gorgeous model!
Thank you! Of course I see everything wrong with it but I've been staring at it for the past few days, after all.

I wanted to mention two things...

First, I'm totally sold on Zbrush. It's amazing what you can do in there in terms of manually fixing defects. I think this is exactly the tool I need to bridge the gap that my photos are falling short on. I've had so much fun with the program in the past week week that I decided to buy a drawing tablet thing. It was relatively inexpensive (I just needed something basic) and will give you more control in Zbrush (e.g. control over pressure). Haven't tried it out yet but I'm ready and excited to flex my nonexistent art skills.

Next thing, I got an ad for a kickstarter product; some sort of thing you attach to your camera to do focus stacking. I wasn't aware what this is but it sounds very cool. For those of you into photography, you almost certainly already know about this. But for those who are not, focus stacking is where the camera takes the same picture multiple times changing the focus each time. With the end goal of getting the entirety of what you're photographing in focus. You can imagine how this would be useful in photogrammetry. If my explanation didn't make sense, it will be more evident in this example from the-digital-picture.com website:

Focus StackedStandard
ImageImage

Well I'd gotten a new camera over the holidays. Seeing that kickstarter thing made me think this is some super premium feature/technique. I never imagined that my new camera (Canon RP) actually has this feature built in (which is surprising because it lacks some other things I wish it had). So I'm looking forward to trying it out this weekend. No idea how/if it will effect the software's ability to calibrate images but we shall see.

For anyone who is interested, sketchfab and RealityCapture are running a challenge/contest right now. The contest is to scan your favorite toy using the RealityCapture software, then upload it to the sketchfab website. RealityCapture is pay-per-input, so the software itself is free. Since it costs money to purchase input licenses, they're providing entrants with 20EUR of credits to use for the challenge. The contest runs through March and I'm probably going to try to scan something to enter this weekend.

https://sketchfab.com/blogs/community/s ... orite-toy/

I know, I know, "dear diary" right?

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SneakyRobb
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17 Mar 2020, 00:21

Interesting contest. I have some time at home right now. I might try this on my Optimus Prime or Tallgeese models

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snacksthecat
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17 Mar 2020, 03:25

Those would be cool to see!

One additional thing that might be helpful are the coded markers:
https://support.capturingreality.com/hc ... l-version-

They're little barcode-like things that get automatically detected in the images they appear in. The software creates a control point for each of the markers. I'm not sure if it is more effective than manual placement of control points but I wanted to try it out. I don't use this software enough to be able to know if there's a difference, sorry to say.

I'm trying to scan this wifi camera car thing. It's full of pitfalls but it will look so cool if it all comes together.

Image

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SneakyRobb
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18 Mar 2020, 15:28

Hi. That makes sense and is cool. I know you said that the narrow border areas can be a bit of an issue sometimes, so such markers make sense.

Does this robot device save times in terms of manually turning? Were you using a "lazy susan" sort of thing before where you would manually turn it by hand?


Also this is the dental scanner that my dentist used I think. Pretty fast machine actually, but that is to be expected when it costs tens of thousands of dollars.

https://www.youtube.com/watch?v=a40pLVe3pVY

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SneakyRobb
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20 Mar 2020, 20:08

Hi,

So I printed some miniatures I was going to send to snacksthecat, but they are at my parents house. They are self isolating with no symptoms. To be on the safeside I will wait for them to hopefully come out of the 14 days symptom free.

I wont send the models until that time. They do exist though and with some sanding/painting I think they would look really cool!

miniatures.jpg
miniatures.jpg (336.33 KiB) Viewed 547 times

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snacksthecat
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03 Apr 2020, 01:49

SneakyRobb wrote:
20 Mar 2020, 20:08
So I printed some miniatures I was going to send to snacksthecat
Very excited to get these. I can't say thanks enough, I've never had anything 3D printed before. Really piqued my interest and got the gears turning in my head.

So I recently bought on MM a hi-pro HHKB with fancy aftermarket domes. I'm really enjoying typing on it, even more than my primary board that I use almost always.

Image

It also looks just amazing with the upgraded caps.

The only thing about it is it has a ridiculous sticker on the back. I won't spoil it but I'll say that it's slightly NSFW, just barely. So maybe that gives it away but you'll see soon enough. Strange as it is though, I think it gives the board some character so I'm going to leave it on. It is on the bottom, after all.

I do have one photography question, and it's a bit of an emergency since I want to start shooting in an hour or so. So if anyone knows the answer or where to direct me, I'd be super grateful.

My question is about lens sweet spots. Is there an easy way for me to figure out the sweet spot for my lens? I'd like to use this Canon R 24-105mm because it takes great pictures. Even my untrained eye can see that much. But I have no idea what aperture / focal length I should use for maximum shapness + good amount of depth of field.

I have been setting the aperture to f22 thinking that's optimal, but I guess I'm pretty far off in my understanding. Yes it gives high depth of field but probably am suffering quite a bit in overall sharpness.

I've tried googling around a little but most of the stuff I found is over my head. It'd be great if someone familiar in the art could guide me a bit. If not, I'll just dial it back a little and hope for the best. The show must go on! (going a little crazy with all this time at home can you tell?)

Anyways, thanks as always for any tips/tricks.

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snacksthecat
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03 Apr 2020, 06:07

Finished taking all the photos. I ended up shooting with the lens set to 50mm and f11. I guess the sweet spot for most lenses is more toward the center? The pictures were very sharp, but definitely didn't get the same depth of field I had at f22. I'm not sure how much this matters, though, because I've switched up my workflow to be less dependent on the "far away" photos and more on the close-ups.

I think I nailed the white balance; something I usually screw up. This was probably the first time I've taken a proper custom white balance input picture. I guess I could really benefit from a beginners level photography class but I'm lazy and stubborn so that will probably never happen. But yeah, the color matching for this model should be very good.

Going to start processing the pictures now. Hopefully this photoshoot wasn't a waste of time.

Image

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snacksthecat
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04 Apr 2020, 21:15

Well it looks like my weekend project is all done, and the weekend is only beginning. And just as well, because I'm now wiped out and don't feel like doing much of anything. I feel like this pattern happens to me a lot...

So yeah, I jumped the gun a bit and did this one over a few evenings. It turned out awesome, but it also has many scannable attributes working in its favor (good shape, lots of features, etc.)

It has a few stickers on it. One of which is a "hentai auto club" sticker, so ever so slightly nsfw. I decided to leave these stickers on because they make it more interesting. Here's the scan:

https://skfb.ly/6RBVH
Image

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ramnes
ПБТ НАВСЕГДА

05 Apr 2020, 22:39

Just discovering this thread, that's awesome! And that last HHKB JP came out really nice. I didn't even know that photogrammetry was a thing, although I worked in a company that is doing almost exactly this a few years ago.

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snacksthecat
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08 Apr 2020, 23:04

Over the past few days I've been twiddling my thumbs wondering what to do next. I don't feel like scanning another board right now because it requires me to set a lot of stuff up and creates a big mess. So I shifted my focus to my PC to see what other photogrammetry software could produce. This HHKB dataset is pretty safe and reliable, as far as image alignment goes. So I think it would be a good candidate to try running through some of the other programs out there.

I've already finished trying with 3DF Zephyr and it's pretty interesting to see how the models come out differently. Particularly the texturing produced by Zephyr is very different than Metashape.

https://skfb.ly/6RHoS

Here's a comprehensive list of the paid applications I plan to test out with this dataset:
  • Agisoft Metashape
  • 3DF Zephyr
  • Reality Capture
  • Autodesk ReCap
  • PhotoModeler (maybe)
I also plan to run it through some of the free programs as well:
  • Meshroom
  • Colmap
  • MicMac
  • Multi-View Environment (maybe)
  • OpenMVG (maybe)
  • Regard3D (maybe)
  • VisualSFM (maybe)
Pretty much I'm just using this list as a guide. Focusing only on solutions made for scanning at close range (i.e. not limited to overhead drone images). I'd love to try some of the more "enterprise grade" stuff out there, but unfortunately it tends to be very expensive. So I probably won't get my hands on any of those tools unless I change careers or become quite rich. But this roster should keep me plenty busy anyways.

The last thing I wanted to say is that I tried for the first time Colmap. I'd sort of developed a preconceived notion that since it's free, it must not be very good. However, after playing with it yesterday, I found it to be very capable. And it has sane defaults set so that if you don't know what you're doing, you can get by just fine by following the software's suggested path. So for those reasons, I'm going to start recommending Colmap (over my previous preference, Meshroom) to anyone looking for something free to try out. This is mostly based on the amount of control you get in Colmap. There are parameters for every little itty bitty tweak you could possibly imagine. That might sound intimidating, but you don't have to change any of those settings if you don't want to and you should still end up with something nice (best of both worlds).

I'll post the finished results once I feel I've exhausted my shortlist.

Hope everyone is doing well and finding stuff to occupy them during these quarantines.

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snacksthecat
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Yesterday, 22:47

I finally got around to scanning this really old keyboard. It gets boring to use the same exact method every time so I always try to introduce some sort of tweak into the process. This time I experimented with focus stacking, as a way to squeeze more depth of field into each photo. The focus stacking process involves taking multiple photos, adjusting the focus slightly each time. Then run the sets of photos through some software that combines them into a single image with better focus.

This is the method that I used first. But it seemed to really confuse the photogrammetry software. So I eventually just dumped all the photos together and ran it that way. This too confused the software, but to a lesser degree. All in all, some aspects of this scan turned out better than usual, but at the expense of others. There's probably a good way to leverage this, but I don't think I'll play around with it much more.

https://skfb.ly/6TFvT
Image

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