Issues when importing a custom animation trajectory

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
1

I am using version 4.4.47 and trying to produce a video in which the camera moves to points in a grid and at each point rotates 360 degrees around the z axis to produce a panoramic view at that location. To do this, I have tried creating custom trajectories in notepad, modifying exported trajectories with the coordinated and orientations that I need. I have run into two issues that I could use some help with:

  1. I cannot reliably modify or import the orientation to the directions I want. I think this is due to some constraints that I do not yet understand. For example, in Pix4D Mapper, if I change the value of omega at a waypoint, sometimes it changes phi or kappa instead to a different value. I am not sure why this is and it makes fiddling with the animation panel to understand how omega, kappa and phi represent directions very difficult. Similarly if I enter what I think are my desired rotations in a csv file and import them, the resulting orientations are often different. In some cases this makes sense (0.000003e07 instead of 0 for example) but other times the numbers seem very different. For example [0, 90, 0] becomes [135, 90, -45]. Does anyone have any suggestions or resourses for understanding how omega, phi, and kappa represent orientation and what constraints there are on the values? I have looked at https://support.pix4d.com/hc/en-us/articles/202558969-Yaw-Pitch-Roll-and-Omega-Phi-Kappa-angles and https://s3.amazonaws.com/mics.pix4d.com/KB/documents/Pix4D_Yaw_Pitch_Roll_Omega_to_Phi_Kappa_angles_and_conversion.pdf.

  2. I am struggling to get the trajectory to actually rotate in one spot and then move to another and rotate again in a way that is visible in the video. I realised that the software cannot compute timepoints if the waypoints are in the same location, so I have made the coordinates during a rotation vary by very small distances (~0.000001m). This works well when rotating in a single locaiton, but once I add a second location to move to and rotate, the allocation of the timepoints means that almost all the time is spent moving between the two xyz locations. Regardless of the speed or length of the video, rotations are alloted 0.00001 seconds between waypoints which means they are basically absent in the video. Any suggestions for being about to deal with this?

Any advice would be really helpful, I am very aware that this kind of video is not what Pix4D Mapper is really designed for, so the answer may be “use something else!”. If that is the case, any suggestions for other ways to visualise specific views in a pointcloud would be appreciated as well.

Thank you very much!

2

Hi David,

I agree that there are some unexpected results when exporting and re-importing edited trajectories. I have had most success by editing the waypoints in the animation trajectory window, rather than editing in textpad.

If I understand your first point correctly, altering phi is likely to produce what you are after? As you pointed out the speed at which movement is produced is locked for the whole animation (we have asked for a feature which enables you to specify the speed/time between waypoints). I would suggest you create other waypoints and set the camera to move very slowly around this cluster of points which will rotate around - roughly- the same position and export a video at a speed which is suitable for the movement around these close points. After this, create a much faster animation along exactly the same trajectory which is suitable for the larger XYZ movements between other waypoints. After exporting the two videos they could be combined in video editing software ensuring the frames align.

Hope this helps!