Photogrammetry of a Downtown Los Angeles Alley
![Photogrammetry of a Downtown Los Angeles Alley Photogrammetry of a Downtown Los Angeles Alley](https://jordanhalsey-public.s3.us-west-2.amazonaws.com/Images/Articles/Photogrammetry-Downtown-Allley-Los-Angeles/Photogrammetry-Downtown-Allley-Los-Angeles-Reality-Capture-002.webp)
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 of a Downtown Los Angeles Alley](https://jordanhalsey-public.s3.us-west-2.amazonaws.com/Images/Articles/Photogrammetry-Downtown-Allley-Los-Angeles/Photogrammetry-Downtown-Allley-Los-Angeles-Reality-Capture-003.webp)
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 of a Downtown Los Angeles Alley](https://jordanhalsey-public.s3.us-west-2.amazonaws.com/Images/Articles/Photogrammetry-Downtown-Allley-Los-Angeles/Photogrammetry-Downtown-Allley-Los-Angeles-Reality-Capture-001.webp)
Photogrammetry Solve in SideFX Houdini
![Photogrammetry of a Downtown Los Angeles Alley Photogrammetry of a Downtown Los Angeles Alley](https://jordanhalsey-public.s3.us-west-2.amazonaws.com/Images/Articles/Photogrammetry-Downtown-Allley-Los-Angeles/Photogrammetry-Downtown-Allley-Los-Angeles-SideFX-Houdini-002.webp)
Photogrammetry of a Downtown Los Angeles Alley
![Photogrammetry of a Downtown Los Angeles Alley Photogrammetry of a Downtown Los Angeles Alley](https://jordanhalsey-public.s3.us-west-2.amazonaws.com/Images/Articles/Photogrammetry-Downtown-Allley-Los-Angeles/Photogrammetry-Downtown-Allley-Los-Angeles-SideFX-Houdini-001.webp)