I use several Quads & Planes, and since they all use WGS84 Lat/Long (w/ altitude for Z coordinate) for image location in the EXIF headers, the process works for each “Drone” & Pix4D.
As most of you, my model is in a State Plane Coordinate System.
My Typical Workflow following the Pix4D instructions & Support Staff comments:
(Images are WGS84, GCP’s are State Plane, Output System is set to State Plane)
Import GCP text file. Pay attention to the N,E vs Lat/Long fields. This is easy to OVERLOOK. Most of us export our GPS points file as Point #, N, E, Z, Description. I just Modify the GCP text file so it matches the requirements for Pix4D input.
Mark at least 3 images per GCP in the Basic Editor before using the RayCloud Editor to mark all images for each GCP. [In simple terms, this “raises” the 3D model to the GCP elevations, since the photos are tagged with altitude as the Z coordinate].
[For those of you that didn’t see the post, Pix4D has a simple app that allows us to use automatic target recognition so we can skip ALL of this. https://community.pix4d.com/t/4549-Try-out-our-new-tool-Pix4Dtagger- ]
Joseph:
I agree with your statements, w/ the same system for images and GCP’s, it seems you should be able to skip the manual marking of GCP’s in the Basic Editor.
Since your images and GCP’s are in the same coordinate system, are you using WGS84 for your GPS points? If not, how are you tagging images in a State Plane (Grid System) and using ellipsoidal heights instead of altitude in the EXIF headers? The reason I ask is I’m working on a way to do this with RTK on-board w/ Pixhawk & I’d be interested if you have image tags w/ true elevations working already.