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Ask HN: How to produce a 3D scan of a car from a mobile phone?

by canxerian on 1/24/25, 6:52 PM with 24 comments

• by tummler on 1/27/25, 6:34 PM

  Quick and easy? Phone apps:

  • Scaniverse - https://apps.apple.com/us/app/scaniverse-3d-scanner/id154143...

  • Polycam - https://apps.apple.com/us/app/polycam-3d-scanner-lidar-360/i...

  • Luma3D - https://apps.apple.com/us/app/luma-3d-capture/id1615849914

  Higher quality (potentially), more time/effort (definitely)? Dedicated camera + desktop apps:

  • RealityCapture (free) - https://www.capturingreality.com

  • Metashape (paid) - https://www.agisoft.com/

• by collingreen on 1/24/25, 7:24 PM

  It depends on what you're planning to do with the scans. There are some great off the shelf photogrammetry and structure-from-motion apps out there, many free. There are also more involved tools that include depth sensors, lidar, or custom scanners. Unreal has a tool for making 3D scans into usable 3D models called realitycapture.

  My advice is to nail down what you're trying to do, end to end, which will help you narrow the field of what to use.

• by monknomo on 1/27/25, 6:05 PM

  I think superfastmatt on youtube has some videos on exactly this sort of question

• by joeld42 on 1/27/25, 6:51 PM

  If you are looking for an existing car, there's a lot of sites selling pre-made vehicle models for pretty much anything, that's probably going to be higher quality and need less cleanup than anything you can get from scanning.

  One of the problems you'll have is photoscanning does not do well with shiny surfaces, as the highlights move and confuse the reconstruction. If this were a model or maquette or something, they would probably spray paint it matte before scanning, which I doubt you want to do with a real car.

  If you need high quality, honestly I'd just hire a hard surface modeller. There are people out there who make cars all day every day. If you just need low quality, Unreal's RealityScan app, Polycam, or AliceVision are good places to start.

• by AyyEye on 1/27/25, 8:10 PM

  Openmvs: https://github.com/cdcseacave/openMVS

  ^ uses OpenMVG: https://github.com/openMVG/openMVG

  Colmap: https://github.com/colmap/colmap

  Opensfm: https://github.com/mapillary/OpenSfM

  Meshlab: https://www.meshlab.net/ (open source)

  I also hear meshroom is popular but I haven't used it.

• by fsloth on 1/27/25, 6:40 PM

  “ client is interested in 3D scanning cars, outdoors and in varying conditions.”

  The implications of these requirements (ie car _in specific location_) is not obvious to me. What are they planning to do with the model?

  Have they customized the frame and / or paintjob or is it a typical production model?

  In the latter case it would likely be easier to source a 3d model rather than scan it.

  If it’s some “playing around” Luma is pretty good nerf based scanner.

  Without nerf you might have a hell of a problem with the specular surfaces.

  If it’s production use with a budget I would recommend subcontracting the scanning - there are parties professionally doing this.

• by Tzk on 1/28/25, 5:46 AM

  The main issue isn’t software or the phone in this case. It’s the task itself. Photogrammetry is one of the worst options to scan a car. Let me answer why:

  Photogrammetry relies on unique points on an object. Imagine that the software doesn’t have any information besides what’s visible on the photos. Basically it tries to match the same points on different photos and is then able to reconstruct the object by estimation.

  This works great for objects which got a unique texture or many unique points. Like a newspaper, which has a lot of non-repeating text and thus a non-repeating texture. This doesn’t word great for single color objects, as the software can’t distinguish different points on the object.

  This does also work on matte,opaque objects, as reflections will show the surroundings and may alter the color.

  Now combine the above: cars are usually single color, shiny and have very little corners and edges. This is photogrammetries worst nightmare. Even if you coat the whole car in a single even layer of something, then it’s still single color…

  What works (but it’s a painful task!) is to sprinkle colored matte dots onto the car, preferably in a random pattern. Then you take houndreds of photos of the car. It’ll take a long time and it must be done in an even lit place. So no direct sunlight but a cloudy day or inside a building with a lot of indirect lighting.

  In short: Don’t try it and buy a scanner like Einstar instead. Renting a more expensive scanner is also an option. You’ll still need to coat the car, but it’s faster and less painful.

• by franklovecchio on 1/27/25, 6:53 PM

  The Einstar Vega goes for $1,799 USD, which is about 2x the price of a standalone iPhone. The scans will be better than anything you can get using a mobile phone (though it's essentially just that?). Lots of videos on YT comparing the Vega and OG Einstar, especially for automobile scanning.

  The downsides of the Vega I mostly didn't see mentioned on YT:

  - Required an account to use

  - Required WIFI to setup (don't need WIFI past that except when updating)

  - Required an app to get scan files off it, but will work for your OBJ use case

  Battery life has been a few scans. Do the processing later and get the scans up front.

• by macinjosh on 1/27/25, 6:06 PM

  If you are on a budget maybe check out Creality's new offerings in this area.

  For ~$1500 you can have a handheld 3d scanner. Their marketing materials show a scanned Hummer hood and a car door. I have never used it though so I am not endorsing it.

  https://store.creality.com/products/cr-scan-raptor-3d-scanne...

• by ryandamm on 1/27/25, 6:29 PM

  That’s going to depend a whole lot on their budget, your capabilities, and the final requirements — is this being used for visuals, or metrology?

  I have suggestions for getting visual fidelity but if you’re looking for an explicit 3D model maybe that’s not what you’re going for. (There are new approaches like NeRFs and Gaussian splats that don’t use traditional 3D formats, but look truly great.)

• by neilhcox on 1/27/25, 7:18 PM

  I've had a lot of success scanning engines, engine bays, and crossmembers with Scandy Pro on my iPhone 15 Pro. It's slow going, you really need to be patient and methodical to get a good scan. I often make multiple scans and combine them into a single model on my computer.

• by avgDev on 1/27/25, 6:15 PM

  You would need an actual 3d scanner. I've used iPhone 12 Pro and scaniverse to scan some things outside my home but it wasn't as accurate as I would like.

  The more accurate you want to get the more money you will generally have to spend.

• by ThouYS on 1/27/25, 6:06 PM

  polycam or scaniverse (gaussian splats though)

• by Bancakes on 1/27/25, 6:46 PM

  The best 3D models I’ve seen are from iPhones and their FaceID camera. It’s an infrared photogrammetry beast.

• by 6SixTy on 1/24/25, 7:27 PM

  3D scanning is not some niche cottage industry. There's loads of different solutions by companies ranging from Epic Games to Autodesk, DIY solutions using Xbox Kinect, to dedicated devices. Just depends on what you are trying to do and tolerance for dodgy BS.

  And oh, you aren't likely to get a clean 3D model from the get go, more likely is that you are going to generate a point cloud that has to be edited to get a usable 3D model.

• by knicholes on 1/27/25, 6:45 PM

  Mushroom works fine for me for photogrammetry.

• by Davidbrcz on 1/27/25, 5:56 PM

  Pix4d catch