Photogrammetry of a Downtown Los Angeles Alley

Photogrammetry of a Downtown Los Angeles Alley

Capturing the Alley

I have always loved the south-end alleyway at 6th And Lindley Place. The alleyway dead ends and a classic sign reads Los Angeles Theatre, Now Playing sits almost at the center of the wall like a call to the past. With the Ganek Immersive Studio at USC, we are developing a prototype Virtual Reality crime scene experience. Lead Developer Stephanie NG, student Nathan Fairchild, and I captured the alleyway using our DJI Mavic Pro 3, a Sony R with a 25 mm Zeiss Batis lens, and additional photos using an iPhone as a backup.

Photogrammetry of a Downtown Los Angeles Alley

Photogrammetry Solve in Reality Capture

To get the photogrammetry solved, I used all of the photographs and one of the drone videos. 4,362 photos were used and close to 4,000 cameras aligned in the first pass. The large component had over a trillion points. First, I created a 3D model with the Normal Detail settings. The initial photogrammetry model was solved after roughly eight hours. I used this to import it into Houdini and do a quick check of the quality of the photogrammetry. After this, I did another capture in Reality Capture using the High-Quality settings.

Photogrammetry of a Downtown Los Angeles Alley

Photogrammetry Solve in SideFX Houdini

Photogrammetry of a Downtown Los Angeles Alley

Photogrammetry of a Downtown Los Angeles Alley

Photogrammetry of a Downtown Los Angeles Alley

Photogrammetry of a Downtown Los Angeles Alley