Photogrammetry vs. "Real" 3D Scanner

so the European Parliament has passed the copyright reform that lobbyists were so keen on getting yeah that's that's a big oof this is gonna make my job a lot harder and it's also gonna restrict free speech on the internet so not really a great thing but at least I have the Midwest reparable to look forward to later this week it's Tuesday right now and I've got two more days and I do want to make one more video before I head out and everything is just gonna be Murph coverage and I didn't want to make a getting started with do it guide but I think that needs a bit more care so today we are going to do photogrammetry versus a real 3d scanner which one is better which one is better for which application and yeah which one is right for you so you've probably heard about photogrammetry where you go around with a camera I'm gonna use my phone around an object and just take a couple of photos and there's softer that it's gonna stitch those photos together into a 3d model by looking at you know the different perspectives you get out of each photo it can determine how each part of the image moves and it can reconstruct a 3d object from that in the other corner we have the shining 3d ein scan se they also have an SP which is a slightly better version of this but functionally these are the same this is pretty neat system so it's got a projector in here that projects out a patterned light beam and then it has some cameras on the side that kind of do the same thing as with photogrammetry where they determine how each of those light beams has shifted in the image and with that it can reconstruct a 3d model as well so to test out these two techniques we're gonna use a few different models these are kind of covering the entire spectrum of what you might be scanning from you know a simple white plaster cast I think I don't know what material this is yeah this has no texture at all this is just plain white it has no color to it I'm also going to be using this gremlin goblin that has a lot of texture that is also dark and non reflective this should be a best-case scenario for both and then I'm gonna use this chrome skull to test how well you know these techniques can handle the extremely shiny materials that don't really have a Tex to them at all and I don't think either one of these techniques is gonna capture this thing at all you can go ahead and spray these with like a matte spray paint or some speckled stone like texture but you can do that to any model and it's roughly going to look like this so you can turn several models into the best-case scenario but that's what we have this one for so let's start with category number one cost your phone is a good enough camera to do photogrammetry you can take this put it on manual mode and just walk around the objects this is technically free if you have any sort of recent mid-range or high-end phone software for photogrammetry is also free and open-source you do need a relatively powerful computer to just calculate the 3d model but it's just gonna take longer unless powerful hardware so basically you probably have all the tools you need all ready to do photogrammetry the ein scan is e on the other hand you get the scanner head you get a turntable you get a bunch of adapters and plates and stuff yeah obviously this is gonna cost more than photogrammetry the is gonna see is around 1,500 euros which is you know more than a laptop and a phone so cost goes to photogrammetry so next up let's look at flexibility how versatile are these tools so first of all photogrammetry you can take a camera out anywhere you can scan anything out in the world as long as the texture is correct as long as it has some sort of texture to it you do need it to be somewhat well-lit for the camera to pick it up but otherwise you're pretty free with what you want to scan cars for example because of their the reflective scale don't often pick up well but large statues or buildings that don't have a lot of reflective glass usually pick up very well too so the ein scan and most other 3d scanners are more of a local you bring your scanned object to the scanner kind of approach so the eye scan actually has two different use cases so first of all you have the one with the turntable where you just plop your object onto the turntable itself and then this thing sits on the stand looking at this real quick kind of like so and then of course this guy spins and the scanner projects its light onto the object so this is number one how you can use it so in a static way which just plop your objects on and off but you can also take the scanner itself and take it off of this platform and put it onto a tripod and use the scanner without the rotating platform where you have it static in one place it takes one perspective then you move it to another perspective it takes another shot and emerges those automatically however there is the issue of stray light because the projector in here is not very bright you can't really use it outdoors in the Sun even a cloudy day is too much stray light already so really you're kind of limited to indoor scans or scans at night nighttime with no stray light is actually the best case scenario for the scanner which is why you typically even want to dim your room lights or turn them off when you're scanning something with this indoors with photogrammetry you can also use any camera you have be it a phone mirrorless or an DSLR or even your drone and fly around an object the castle a mountain or something and then input those photos into the same software and you're gonna get a large-scale 3d scan so flexibility given the limited size that this thing can scan and the requirements for your lighting setup I think photogrammetry is way more flexible and way more versatile for scanning things so another point for the humble camera so next up let's look at how capable these techniques are when it comes to different surfaces and just varying types of objects and this one is actually pretty clear with this darker textured golem both of these techniques do a really great job of course with photogrammetry you do have to make sure that you're capturing all the angles but both of these capture this guy just absolutely perfectly next up this plain white texture list cherub is still pretty good on both of these techniques the Aisne scan se just has an absolute blast with it because this is like the best case scenario for it it's bright it's not very shiny it's actually pretty matte and overall it just fits into the scan volume perfectly so this is kind of the best-case scenario for the shining 3d scanner with photogrammetry you do run into the limits of the technology where for example the legs and arms just are smooth textures it still kind of picks up based on your lighting setup so if you have a lot of highlights and shadows those are still being picked up as texture but overall this is this is kind of an edge case for photogrammetry this may or may not work but on the other end of the spectrum this is a white model so this works really well with the shining 3d scanner if this were black of course it wouldn't reflect a lot of light out of the scanners so a black object even if it's just a matte black surface is kind of really hard for this one already so this one's good because it's white but if it were black you'd have a bit of a harder time but that also applies to photogrammetry and lastly the chrome skull neither of these scanners are really able to capture this particularly well or at all so that's kind of a neutral between both of them with a super shiny model like this if you put for example chalk powder over it or talcum powder or anything that is kind of matte then the ein scan is gonna have a much easier time whereas photogrammetry is still going to sort of struggle with this because it's it doesn't have a ton of you know texture to it where you can make out individual bits like up here where you have all these individual patterns and features on it so when it comes to capability guide scan is a clear winner for this one [Music] so next up let's look at speed and that doesn't just mean how fast the actual scan is but also the post-processing time even on a high-end computer both of these reconstruction methods are really Hardware intensive they both use in video CUDA acceleration but they also both require a ton of CPU power I'm running thread rippers and 1070 TRS on this one and 1080 TI on the workstation and still the photogrammetry software mushroom takes upwards of 10-15 minutes to reconstruct a 3d model out of a set of like 10:15 phone photos so that takes a long while the ion scan software is still not instantaneous or anything but it is a lot quicker and takes less time to reproduce and on top of that you also kind of have to account for the time that it takes you to scan something or to take the actual input material with a phone or a camera you do have to run around your object and just make sure you cover every single angle up down and all around the object on the Aisne scan the turntable does a lot of work for you and what you can also do is you can then reorient the model in different way and rescan and it's automatically going to stitch it together into one complete model so the scanning process here is really automated and integrated and you know with photogrammetry to be take the photos on one device then you take those over in HD card or a USB cord you transfer it onto your computer and then load it into the software here it's just an all-in-one solution and it's all in like one neat package the scan times themselves on the Aisne skin especially if you use a lot of subdivisions on the rotation very easily pile up into like the 10 15 minute range as well but it's an automated process that you don't have to babysit that combined with the fact that the processing itself is faster on the ion scanner i think is another point for the shining 3d eins can I see so let's look at ease of use and these two are you know more than just the hardware itself it's also the software that comes along with it with the Aisne scan and any other bike hardware scanner you do have some set-up time this is like a few minutes of assembling this and then you have to calibrate it before use if you've taken it apart you put this plate on into this fan and then you scan it from every perspective it's integrated into the softer though and that kind of guides you through the calibration process and you do have to do that every time you take it out of a box and reassemble it just to make sure everything is perfectly lined up with photogrammetry you kind of just take out your phone and you start snapping you do you have to set it for example to manual mode just to make sure that your exposure is correct and with this one I had the problem that my phone wanted to expose it to dark especially on a bright background like this so you do have to set your phone to manual mode for perfect results and then you know just walk around it and take the photos as far as how easy it is to then take your scan data into your processing software the ions gonna see is way easier because like I mentioned it just directly transfers it into the software with your phone you do have to download it somehow onto your computer USB code whatever and then one thing that I also ran into specifically with the g7 the LG g7 is that it doesn't write the metadata for what the 35 millimeter equivalent focal length is so basically how wide your lenses it doesn't write it into the image data so the soft I had a bit of a hard time figuring out how wide that is so you can either change the defaults in mesh room or you can add that information to the image metadata but that's an extra step each time you want to scan something with basically all the photos you take then when it comes to actually getting the 3d model out of your software the ein scans softest set gives you the options to for example merge different perspectives so you scan your object like this then like that where you scan it in a totally different orientation and it adds all those details together automatically you can also trim unwanted objects for example if you had your model set on a platform or you just have some areas that he don't want scan you can trim those off very easily on the other hand with photogrammetry your software at least mesh room in this case just gives me the raw mesh just the raw object file and then you have to take it into another piece of softer to trim off unwanted edges or if you can't get to every angle of your model you actually have to put it up on some sort of stand that you didn't have to trim off or manually scan different perspectives and then merge those it's a bit more of a manual process to be honest and it's not really that easy that's streamlined though mushroom is a really great software and overall with photogrammetry there's just a lot more manual work involved that kind of requires you to know what you're doing also things like exporting the sto and then getting the right resolution so that it doesn't crash any software try to load it into you get really high detail models that may actually be too much detail with the ions can you get those export options on how much detail you actually want so overall for usability and ease of use I think the Aisne skin is the overall better product simply because it is a complete product of the hardware and the software I kind of worked together with photogrammetry you're more open to using whatever you have but that also means it is piecemeal out of this piece of soft and this piece of soft and you have to take your models through each of those so usability I scan so let's talk about accuracy and precision and just basically how well you can use these as a measuring tools o'the photogrammetry you don't really get models that are to scale with photogrammetry what you can do is just put an object into the scan that you know has some sort of known dimension the width of this thing or the length of this rule you know exactly put it next to your model and you scan it along size your model and then scale your resulting scan for this to match that is a manual process and sometimes you also get some weird distortions just on photogrammetry if your camera lens has distortions and the soft that doesn't really account for them properly so you don't always get perfectly to scale and to proportion results but you can't get pretty close on the Aisne scan because it is calibrated with this thought pattern card that is you know very well known spacing you get really high accuracy results you can basically take measurements off of your finished part if the scan is good if you don't have any glitches in your model you can literally use this as a measuring device it is really good for to scale scans and what it is also really good at is producing detail with the Aisne skin you can pretty much see every little grain on these models you can see all the details in the wings maybe a little bit of imperfection in the scan it is amazing how much detail you can get out of the scanner the photogrammetry you can get close you can get really close in detail reproduction I always hold up my phone I'll talk about it you can get really close with detail reproduction but it is highly dependent on the model if you have something smooth like this you're not gonna get a lot of detail if you can't see it then photogrammetry can not pick up on it so that's just another limitation of photogrammetry as is so accuracy and precision goes to the N scan so overall I think the Aisne skin is a better scanner than photogrammetry with a camera but that is kind of true in many cases dedicated hardware for doing a job is usually gonna do a better job than using what do you having and kind of adapting into it photogrammetry is great but it's not suitable for everything whereas this is also not suitable for everything because of the limited build space and you know also limitations with reflective material and external lighting so while the ein scan is they take a lot of wins over just plain photogrammetry you also have to keep in mind that this is free there's literally $0 except for what you need in compute power and in camera hardware but you probably already have that so comparing something that is free to something that costs virtually 1500 euros you know you kind of have to put that into perspective so in the end as with everything it depends the Aisne scan is really great for scanning high detail parts that are kind of small and fit on the turntable whereas photogrammetry you just always have with you you just have your phone with you you can be out in the city somewhere you see something cool you walk around and you scan it with your phone you just take a few pictures that's all there's to it and you have your model when you get home you plopped it into your computer let it process and there you go so I think this is one of the big advantages of photogrammetry you can use it anywhere in pretty much any situation whereas this is just highly situational and you need the right objects and the right setup to use this productively so for all those were some of the pros and cons for using dedicated scanner hardware like the eins can se or using photogrammetry I hope you learned something if you did give this video a thumbs up get subscribed support this channel on patreon do all those things and I'd like to thank you for watching I'll see you in the next one and I also want to give a big shout out to all the patrons who are already supporting this channel or other creators online especially shout out to long-term patrons Jeffrey Nicoletta JH rule-of-thumb Francisco Peebles Hall art Christopher de Phyllis Tudor Merritt Sara Durham Devine Brian raker Andy fair Dexter Julie Johansen Marlon James C Foley Mike Meiji mark arms and robot Homburg as well as nathan hast Dorian Gray and Matthew Oswald who have joined recently in the shelter tier if you want to join the patreon campaign as well there is the big link on screen right now again thank you all so much for supporting this channel and other creators you guys Rock alright see you all at the Midwest repair Festival

Channel: Thomas Sanladerer

Views: 466,067

Rating: 4.8097563 out of 5

Keywords: 3D printing, Tom's, 3D printer, RepRap, guide, 3D scanner, Photogrammetry, Scanning, Einscan, Structured Light, Reverse Engineering

Id: dGJ_XD-fCsI

Length: 17min 54sec (1074 seconds)

Published: Thu Mar 28 2019