Modeling architecture based on 3D scans?

S1mon

I don't typically do architecture scale modeling, but I'm doing a personal project to model my apartment and furniture. I'm playing with various iOS apps and the 3D Scan feature in Onshape. It definitely feels like the future having LIDAR built into consumer hardware like this.

1. For this scale of object, are there any special techniques to do 3D scans with iOS devices?
2. I have an iPhone 14 Pro and a current iPad Pro - are either of these any better than the other?
3. I've played with both scanning from Onshape and importing scans from other apps (including Sitescape, Polycam, and Scaniverse). Are there any others I should use?
4. Has anyone used things like Matterport or other pro level architectural scanning tools (laser, etc)? How can these be integrated with Onshape?

One disappointment going from the 3rd party apps to Onshape is that they build 3D models with color, but they can't be shown that way in Onshape. In retrospect I suppose this is obvious that Onshape doesn't yet have a way to display images mapped onto surfaces, but it would be pretty nice for the 3D scans.

S1mon

So to answer some of my own questions...

I found this youtube channel has some pretty good walkthroughs (quite literally) of using various iOS apps to scan architectural spaces. The short answer is that the LIDAR and iOS APIs are remarkably powerful, but not 100% accurate. There are techniques to improve accuracy (e.g. using a gimbal), but ultimately you'll need to do tape or laser measurements and modify the models that these tools can build, or just model it yourself with the scan as a reference. The built in tool in Onshape is cool, but it doesn't have all the levers that some of these dedicated apps have.

MagicPlan and PolyCam seem to be the most focused on building a schematic level building model which could be imported into Onshape if needed. They both now take advantage of the Roomplan API which Apple introduced in iOS and iPadOS 16. MagicPlan has been out for ages and originally just worked off the camera and the accelerometer to help build a floor plan. Polycam also supports photogrammetry where you just take a bunch of photos and it builds a 3D model by interpreting what shape the object could be (I don't know if this is also used in architecture scale things, but it could be interesting for ID projects). Both MagicPlan and PolyCam allow you to tweak dimensions of rooms, doors, windows, furniture, etc. in a somewhat parametric way. This is where you likely want a laser measuring device to quickly update the dimensions. These can be used through Bluetooth to enter the measurements directly into the floorplans in MagicPlan. I didn't try this, but if I was doing this all the time, it seems like it would be essential.

Matterport is starting to get into mobile (phone, tablet) capture, but they've built their business up on their branded hardware and cloud platform. They provide floorplans as a service and everything adds up, but from what I see in the real estate market, they are ubiquitous.

Another app I didn't mention so far is the generic sounding, but useful 3D Scanner App. It's free, and has been around since Apple added LIDAR to the Pro iPhones and iPads. Some of these apps have the ability to tweak the minimum feature size and/or the max range of the scans. Some can work in point cloud mode or mesh mode. 

For a some detailed tests of various apps against much a more expensive professional LIDAR scan, this study scans a bunch of cars and compares the process and accuracy.

And if you want to spend a bunch more for very pro level app for documenting things like crime scenes, shipbuilding, infrastructure, etc. there's Dot3D.