Leap tracking is laggy/choppy for z-axis compared to x- and y-axis

Steps causing the bug to occur

  1. Run the attached composition.
  2. Move hand slowly above the Leap Motion device.

The top 2 points (representing x- and y-axis) move smoothly, but the bottom point (representing z-axis) doesn’t. It seems like it waits for the hand to stay at a high or low z-position for some threshold of time before it updates.

How did the result differ from what you expected?

Movement along the z-axis should look the same as along the x- and y-axis.

Other notes

  • Vuo version: 0.9.0
  • macOS version: macOS

@bnvisuals commented on Leap motion refresh rate and general performance :

Just plugged in my leap after all this time, on a new computer, and I’m experiencing some glitches. The Z-axiz is choppy. Any Idea why this would be?

In Vuo 0.9.0, we updated the Leap nodes to use the “stabilized” tracking data provided by the Leap Motion software. This was overall an improvement, as it fixed the constant shakiness in the data.

But, according to https://community.leapmotion.com/t/z-axis-accuracy-is-not-good-as-x-axis-or-y-axis/1376, a side effect of using stabilized data is that, for some reason, the z-axis doesn’t track as well. The difference is apparent if you run the attached composition (080 and 090 versions) in Vuo 0.8.0 and 0.9.0.

Next steps:

  • Try updating the Leap SDK version used in Vuo.
  • If that doesn’t fix the problem, file a bug report to the Leap Motion developers.

TestLeapAxes.vuo (4.82 KB)

TestLeapAxes-090.vuo (4.7 KB)

TestLeapAxes-080.vuo (4.46 KB)


I’m experiencing same issue in Vuo 1.2.2…

@jstrecker, did you mean recompile Vuo with updated SDK or update only libLeap.dylib file in Vuo app? Cause the second option not working for me (or I’m doing something wrong) - after updating libLeap.dylib in Vuo.app/Contents/Frameworks/Vuo.framework/Modules/ the composition doesn’t start at all.

This is very important problem for Leap support in Vuo. Is current status of this bug “scheduled for work” since version 0.9.0? :/

Regards, Teo  

@dumski, sorry I wasn’t clear — I meant updating the Leap SDK as a task for Team Vuo. We did try updating it, and unfortunately it didn’t improve the z-axis tracking.

Since you bumped this thread, we did a little more research — https://community.leapmotion.com/t/z-axis-accuracy-is-not-good-as-x-axis-or-y-axis/1376/11 seems to imply this is intended behavior, and that it’s up to Leap SDK users to work around it. So maybe the workaround (to be implemented by Team Vuo) would be to continue using the stabilized values for x and y (like the newer SDK) and the unstabilized values for z (like the older SDK).

(This bug was reported during Vuo 1.1.1 (7 months ago). I marked it as Vuo 0.9 after tracing back to see when the problem started.)

Fixed in Vuo 1.2.3.