LIDAR and Architecture (Part 1)

LIDAR and Architecture (Part 1)
Iphone 12/13 Pro, the LIDAR is at the bottom right

For several years now, LIDAR has become commonplace for architecture projects, but only for the companies that can rake in excess capital to make the financial commitment.

Those that know me, know that my day job is as an Architectural Technician... So being a nerd, I'm always on the prowl for making my life easier, faster and wiser. A favourite phrase of mine is "work smarter not harder".

On my last phone upgrade, I decided to go for the iPhone 12 Pro. Not because I'm an apple slaphead, but because it's a tool that can be utilised. It has LIDAR and a fully working devkit. I don't have nearly enough skills to work on a devkit for an iPhone but others do. I've probably gone through about 10 - 15 various apps in my time working with LIDAR on the iPhone.

So, let's get to the first question...

What is LIDAR?

There's quite a debate about this question, but it boils down to these 2, and they're both fairly accurate.

"Light Detection and Ranging" or "laser imaging, detection, and ranging"
When it comes to the iPhone, I personally believe "light" to be more accurate than "laser"

If you go out of your way to google "LIDAR" and select images, you'll find an endless collection mostly about cars, and it's an efficient use for LIDAR.  

When it comes to the iPhone, the LIDAR works by sending out infrared light points (sometimes known as a "dot array") and then gets the data from the depth of each point.
The lidar on the iPhone is quite a low resolution.

Low-resolution LIDAR from the iPhone 12 Pro [Source: iFixit]

This is a massive disappointment compared to the facial recognition camera on the front of the phone, which is easily over 10 times denser picking up way more data.

iPhone 12 Facial Scanner [Source: iFixit]
How does Lidar help Architecture?

Architecture is a very broad term, from inspirational designs to practical extensions, from skyscrapers to annexes.

My personal area is quite broad. I'm a lowly technician, but Architectural Technicians, like most jobs, are under-rated and very flexible in their work.

I've worked on a large variety of projects, from mosques, factories, and extensions, to basic survey services such as measured surveys or Fire equipment surveys, to admin work. Someone has to fill in those planning application forms and deal with those pesky build-over agreements.

My main area of work is measured surveys. If someone wants to extend their home, we need to show what exists and how we're changing it. Usually, this involved walking around with Laser and tape measures, Drawing sketches of the layout, attributing measurements to the sketch, and so on. Then, when I get to the office, I draw it again assigning measurements. If I miss a couple of measurements, such as wall thickness or window heights, the stress really can build up as you start scraping other measurements together to get calculations of how things fit together. Luckily, I've never done a survey bad enough to warrant a second visit, That would just demonstrate incompetence.

Measured Surveys are not as simple as some people think. Most people's experience of a measured survey has been the trusty Estate agent. Now there's an oversimplification of a measured survey. They do the width, the length and they move on. but take a look at the room you're in. Does it have a window? How would you draw that wall? You could measure the entire wall, the space to one side of the window and then how wide the window is.
That's great at a 2D level, but then your elevations are going to suffer, did you get the cill height? the window head height? even the room height? do you even know how thick that external wall is? did you ask if the client knew if the walls were insulated? are there any other features on that wall? is there a second window on the same wall?

With Lidar, I can simply "scan" the room or sometimes an entire floor, and do the measurements later. a 3-hour survey becomes a 20-minute survey, then with a good enough app, or recap, I throw on some measurements and draw it. There are still questions that need to be asked like the insulated walls, but for the most part, the work involved has optimised massively. I can get all the measurements from the scan. As long as the whole room was scanned (and hopefully a bit of the room it's attached to) you'll have all the measurements you could need.

There are vast more expensive tools that can LIDAR Scan, but for now, my next LIDAR article will cover more about the various applications I've used for the iPhone, so keep an eye out.