Polycam - 3D Scanning

[GreenBar0n]

Was just watching a video, and the guy was replacing broken parts with a 3D printer.

The thing that caught my attention, was at 15:00 he mentions 3D scanning the project in to Fusion, using Polycam on his phone, to take many pictures and create a 3D scanned model.


Polycam is free for hobbyist's, like Fusion is.
https://poly.cam

Apparently it works best with iOS phones that have LiDAR.
https://learn.poly.cam/hc/en-us/articles/30549091902228-What-Is-the-Best-Phone-for-Creating-Models-in-Polycam

Android phones still work, but without the LiDAR capabilities.

I have an old Android phone, and can't test this. Wondering if this is worth getting a new phone for.

[silvertriple]

Well... People dream about scanner being efficient for parts... But it's not that practical : for used parts, it also includes the part deformations due to usage. The scanner would provide a quick copy of a part with a bent, for example. Your eye, knowledge and brain are fantastic and bent are taken into account when modeling while it is something the scan doesn't account for.

I have a revopoint pop 3, and I barely use it. What it is good for is for is :

• organic part scanning : ex driver figure

• quickly get reference points to create a part that goes on a bodyshell or something like this

At the end, it is good for reference points. But to do a part or modifying a part, let's be clear : it's cumbersome to work with a mesh coming from a scan, in particular due to the zillions of unorganized triangles...

[GreenBar0n]

The 3D scanners will be as good, or better than 3D printing is right now, it's going to happen, just a matter of when.

What I want to be able to do is scan large objects, in order to scale them down, and print them. Polycam looks like a great free tool, just wondering if anyone had actually tried it yet. I may have to get a phone that has LiDAR, to test the abilities and limits of Polycam.

[GoMachV]

Man, I'd like to believe that... but think of a copy machine, a fresh word document always looks better than the best copy, and you have a structure that you can add, remove, change, etc whereas with a copy you can't really edit out a comma or change a word. That's where drawing from scratch will always imo be superior. The 1/24 TOJ body we made was a scan that Kent Clausen did of his personal car, and I took the scan and had a professional turn it into a cad model I could work with. For that use case it was great, but you could never have taken that scan and done anything with it besides using is as a layer to trace in cad.

[Dadio]

As others have said it's a lovely idea but it's not there yet , cleaning up scans to make them useable simply takes ages even on organic pieces like body scans but geometric parts are currently better drawn in CAD .

[XLR8]

If current scanning technology isn't yet good enough to go directly to the printer, might it be good enough to provide lines, control points, contours, etc. necessary to CAD model for instance, the cab portion of this VW bus from the 1950's?

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Is it possible to import the scan into say Fusion360 and use it like a buck to create a reasonably accurate surface model?
I have no experience with the process so I'm asking.

[silvertriple]

Is it possible to import the scan into say Fusion360 and use it like a buck to create a reasonably accurate surface model?
I have no experience with the process so I'm asking.

Yes it is possible to import scans directly in Fusion360... but it's clearly difficult to deal with them : a mesh resulting of a scan is a set of unorganized polygons and it is very heavy to use. Just to give you some idea of what it represent, take a stl of a part defined in parametric and import the mesh in Fusion360 : it is way more difficult than to work with a step (and as opposed to a scan result it is relatively organized).
You maybe able to use the scan to create a set of reference points on different plans (I did it with the Manx TT 1/8 bodyshell), but it was painfull and long.
Another thing I did was to use a scan to print a driver figure. In resin print, as you move the printed part out of the build plate and support, it mostly work. Saddly, to original plan surface is not plan on the scan, and it results in some adhesion difficulties to print it on a FDM printer (and yes, you can always do a cut to get it print, but that says long about scan precision).
Ultimately, Fusion360 is not suitable to work with mesh, and it's probably better to work with Blender or some other tools in this case, but the assembly with a parametric object will be the issue...
So theorically you think about something simple, but it's not that simple yet. And as precision of scans increase, it also increase the number of polygons you get from the scan... making it even more difficult to manage.
At end :
- for anything geometric : eyes + caliper + brain/knowledge and parametric remains the way to go
- for anything organic, maybe of use, but may require quite a good knowledge to be able to work it

Additional note : on Tamiyabase, there is one guy who is former game developer, and he did some bodyshells based on original 3D models used in games (and some of them are available out there). That might be something to research about, because most of the modelisation is already done in this case...

[GreenBar0n]

In the video attached, he had no trouble scanning the object in to Fusion, and using it to make a part with the correct dimensions.

If no one has tried Polycam yet, I'll find a phone with LiDAR and give it a try.

[XLR8]

In the video attached, he had no trouble scanning the object in to Fusion, and using it to make a part with the correct dimensions.

If no one has tried Polycam yet, I'll find a phone with LiDAR and give it a try.

I believe it's worth trying.
BTW, could you please post another link to that video? I can't see it in your original post for some reason. thanks.

[GreenBar0n]

I believe it's worth trying.
BTW, could you please post another link to that video? I can't see it in your original post for some reason. thanks.

The software and scan app is free, I think it's worth a try too. Might take me a bit to get something with good LiDAR though.

Here's a direct link to the Polycam scan process, at about 15:04 it begins.
https://youtu.be/lYPmiEJCawY?si=Zp2uC4xWiLmIHxJR&t=905

This 1:8 die-cast model would be an interesting test for the Polycam scan. If the process had trouble with certain parts/components of the model, I could remove the parts and scan and scale them individually. The texture is very smooth also, which might save some time cleaning the scan.