Arena questions

[aleksbg33]

Hi,

As a recent owner of 12 S250e I have couple of questions regarding arena:
1. After a recording I always get last frames frozen. Any chance I am doing smth wrong? (calib results are always exceptional for all cams)

2. Skeleton setup with custom markerset. I have read previous posts on this topic but still have some issues:
- by default I am shooting ROM facing +Z (arenas skeleton is by default turned to -Z) so I rotate it to face +Z, align it, scale it, assign markers... but when I want to see results skeleton screws and cant get any kind of good tracking.

3. Noisy/shaky marker. Sometimes it happens that some of markers are a bit noisy although it is seen by 5 or more cameras at same time (it usually gets shaky when some camera see it than not then again sees it) I guess it happens when camera cant decide which marker to track as it see 2 markers in a line. Is there any trick to solve this problem like refine thing that software can automatically discard that camera to get better results.

4.This more like a wish list:
-enable exporting to c3d or trc without trajectorizing (for those who wants to do clean in other sw)
-advanced manual (i would be happy if I can at least get some kind of work in progress copy)
-undo in skeleton wizzard
-refine calibration option using marked actor or smth

Please have in mind that I am new to your system so if any of my questions are silly...
Generally I am very happy with your system.
Keep up the good work.

[NaturalPoint - Mike]

Hello -

First things first, what version of Arena are you using?

What do you mean by the last frame freezes? What exactly goes on?

Custom markersets are a bit iffy in Arena, but they can be done. You have to define the hips and build everything heirarchically from there. Perhaps if you took a screen capture video of your definition process we could look at it and see whats going on

Shaky markers can sometimes occur if a marker is dropping in and out of a camera's view, or the ray is right on the threshold of your residual. Try adjusting your residual down a point or two to see if it gets rid of the shakiness.

Export without trajectorization is currently not available because the labels that are used in c3d encoding are added during trajectorization. I don't believe there are plans to change this.

A manual is coming for the next version, and should be released either during or sometime after the release date.

Undo in the skeleton wizard is something that I've been wanting myself for a while now. I've got a request in to our development team to see if this is a possibility.

I'm not sure what you mean by refined calibration using marked actor or smth. Could you elaborate?

[aleksbg33]

Hi Mike,

Thanks for reply.
I am using 1.8.0 Beta 1 version as it is the last version that my license can handle.

Every capture finished with markers being freezed on last 3 or 4 frames (I can send pt2 files as example). This happen on every capture we had so far.

Custom MarkerSet
I will send you a step by step images how I did it on your email

I have lowered the residual and it is a bit better but I guess it would be still be kind of nice if camera that see overlayed markers (check MasterCard logo) can actually ignore both markers.

Refining calibration using actor that is walking through the volume is something that is doable on MAC (Motion Analysis) mocap system and that where I have seen it. Have in mind that I am a MAC user for a long time and therefore all my logic and ideas comes from that system and since there is no good manual, for now , i have to ask if it is refining posible with actor inside volume.

Thanks again for all your answers.

[NaturalPoint - Mike]

The markers in the provided .pt2 appear to properly function during all frames, with no freezing as described in the last few frames of the capture. You may want to consider updating to 1.8.1 Final, as changes made during the beta process may be responsible for the correction.

As for the custom marker set, it's possible to do but there will be more breaking than with a standard marker set. Improvements to the custom marker set engine are coming with future versions.