Tech Scout for Jeffrey Short Film at an Art Space in DTLA

Phil at an art space for the short film Jeffrey.

Anyone who knows me personally knows that I usually put too much on my plate, so on top of my regular job and Changelings, I’m also helping my friend produce her short film, Jeffrey. It’s a highly technical film being done entirely in the virtual realm.

Yesterday Team Jeffrey went to scount a location that might become our stage for pre-visualization of Jeffrey. It turns out that the space might be a little small and there might be too much magnetic interference from metal embedded in the floor. So this was less of an aesthetic scout and more of a tech scout where we go to see if the space / location fits within a certain set of technical perameters. You know, size, electric capacity… magnetic fields (gremlins).

Even though the technology we’ll be using for our motion capture is advanced, the boring, simple bits of the universe still like to throw monkies in our wrenches. Too many metaphors? Too bad!

Phil drags phone to find magnetism for motion capture systems.

The sensors we will be using to capture our actor’s motion become disturbed by too much magnetic interference (gremlins, monkies and what have you), which will result in unuseable data. Wherever a magnetic field rises to a certain threshold, the data becomes corrupt. So if there’s a deposite of iron ferrite in the cement, BAM! The legs get ripped apart… digitally speaking. Same with any limb that approaches strong magnetic field.

In order to find out whether or not we can use the sapce – and if we could which spots to avoid – we had to take a magnetometer and drag it along the floor.

It seems silly, but apparently the way you measure the floor is take your phone – using a suite of tools called Physics Toolbox – and drag it over the floor with a piece of paper. The sensors within the phone apparently include a magnetometer!

Taking magnetic readings with an iPhone.

This is what the output looks like up close.

Screenshot of iPhone taking magnetic readings

We treated the process like an archeolgical dig. We used the pre-gridded cement floor to track our progress while keeping the orientation of the phone the same so as not to confuse which axies were which. Once we were done, the program spat out a 40 page spreadsheet with all of the readings, which I won’t bore you with here. We’re goin to be sending these back to our software expert to see if the space is kicking off to much magnetism.

If all is well, we can move forward with this space as our pre-viz location. If not, the search will continue.


The other goal of the day was to try and capture a 3D scan of the room to have a look at the environment in 3D. Unfortunately, our scanning software wasn’t behaving, so we chose to try some photogrammetry to stitch together a model. I’ve done some before on small objects so this was new to me, but we did end up getting a model out of the process, though I’d say it’s a bit impressionistic.


3D scan of art gallery
3D scan 2 of art gallery


3D scan of art gallery from above 1
3D scan of art gallery from above 2
3D scan of art gallery skylight.

Here’s a photo of the skylight for comparison.

Art gallery

As you can tell, the level of detail doesn’t work for our purposes and I think we’ll have to go back for a few extra photos. The key here is more data. We need to probably take about 10-20x the amount of photos to get the necessary detail we need to be able to build out the environment so we can test it out. Between that and the magentic readings, we should know whether or not this space is right for us.

If you’re interested in fantasy based projects, please have a look at the Seed and Spark page for Jeffrey. If you’re interested in what it’s like trying to get a project like this off the ground, and the technical aspects of a virtual production, have a look!

It’s a very interesting – and dare I say exciting – process.

In the meantime, keep an eye out for those magnetic monkeys in the gremlin’s wrenches.