Pix4Dcatch LIDAR Major Problem?!

Hello Pix4D Team and Community,

I am not sure if this topic suits more into the Pix4Dcloud or Pix4Dcatch forum but I have a pretty interesting and maybe big “problem”. First of all here are some Projects that I would like to share:

  1. Pix4Dcatch(Iphone 12 Pro Max with LIDAR) + vidoc(100% stable RTK signal) + Pix4Dcloud processing:

  2. Downloaded the images of 1 and uploaded it manually into the cloud but without the depth data:

  3. Downloaded the images of 1 and processed it with Pix4Dmapper “3D Models” template locally (without any gcps or manual “changes”):

  • Didnt uploaded into the cloud yet, but the results are “perfect” and as I expected it to be.

So I have multiple question and maybe multiple problems here that I need to understand:
1: I had problems with alot of scans where I walked a “loop” around a big object(1000 images+)(for example: stockpiles) even though I always make sure that I have enough overlap and the end (10-20%). When I processed the images with Pix4Dmapper locally I usually got a pretty good result…

2: Could it be that the LIDAR data is making the results “worse” the longer the scan gets? (cause of the range drift effect / IMU)

  • Why are the results of the 2. Project “better” at the starting point of the scan (why was the cloud able to close the loop at that point?) even though I have less information (no depthmaps)
  • Why is the loop at the 2. Project open at a different spot then the 1 project? - Could it be because of the resolution since the cloud automatically has 1/2 image scale if you upload it manually?
  • The initial camera position (quality report) was perfect but after optimization the position becomes wrong.

I am the techlead of bld:it - Werner & Schlei Ingenieure, we are working very close with you and vigram together. If it helps we could analyse/discuss the situation with you in detail in a meeting since we face the problem with open loops (usually with bigger scans / 1000 images+) often.

Kind Regards,
Anton Schlei.

Hello @anschlei, I believe that you are already in contact with our team. They will reach out to you with all the information.