Gesture Recognition on Python3

[cipulot]

Hello there,

A little bit of preliminary infos. I've installed the v2 sdk and followed the tutorial on how to compile the library for python3 (I'm on python3.7.7, configured for 64bit).

For now I'm able to get the coordinates in the reference frame that the sensor uses for the palm position and that's good, this means that the compiled files works as expected.

Now I'm implementing gesture recognition in one of my projects (swipe in particular) but I've encountered a problem...
It seems that the function frame.gestures() returns always something even if no gesture is performed (even if no hand is inframe).
An example of the output using print(frame.gestures()): <Leap.GestureList; proxy of <Swig Object of type 'Leap::GestureList *' at 0x0000000003344150> >

I've crosschecked with another pc with python2 and sdk 2 configured and I receive this kind of output only when an actual gesture is performed. It seems that the sensor signals a gesture even if no hand or movement is present...very strange, and nonsense to me.

Have anyone had the same issue as me with Python3? I know that is not natively supported but I really need to stay on P3.

Thanks in advance for the help.

[CptOblivion]

Do you still have the guide to recompiling for Python 3? I'm trying to make a Blender addon for the Leap (so I'm stuck with Python 3.7) but the link in the Leap documentation for the Python 3 compiling guide isn't valid any more

[cipulot]

Yeah, when they moved to the v4 sdk a proper migration of old url wasn't put in place....
Here's the link: Recompile for P3

Note that the newer version of SWIG will have complains about indentation and other stuff with the input file. Just use the 2.0.9 version that is still downloadable.

For the rest the guide in the above link worked well for me (64bit, python 3.7.7). Feel free to dm me if you have problems with the compilation.

[CptOblivion]

Thanks so much! Got it working and (sloppily) hooked into Blender.

Taking a poke at your problem (I'm not using gestures myself but I felt guilty for hijacking your thread), I'm sort of scraping at the edges of what I understand here but it looks like maybe the swig-generated dll isn't properly passing along Python's attempts to address an array- I get the same output as you're getting (different memory address of course), also regardless of whether a hand is in frame.

I noticed that code copied and pasted from the documentation verbatim throws an error (this is from the keytap gesture page):

for gesture in frame.gestures():
    if gesture.type is Leap.Gesture.TYPE_KEY_TAP:
        key_tap = Leap.KeyTapGesture(gesture)

the first line gives me

StopIteration
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
  File "[my horrifying folder structure redacted]\Leap.py", line 26, in LeapControl_Handler
    fp.close()
SystemError: <built-in function delete_GestureList> returned a result with an error set

[cipulot]

Yeah, I got the same sensation about the swig.

After some digging and debug this code works well for the detection:

from Leap import SwipeGesture
#STUFF

class SampleListener(Leap.Listener):
# State of gesture names
state_names = ['STATE_INVALID', 'STATE_START', 'STATE_UPDATE', 'STATE_END']

# STUFF

def on_frame(self, controller):
    # Get the most recent frame
    frame = controller.frame()
    # Get gesture as list
    gestures = list(frame.gestures())
    # Count gestures
    numGestures = len(gestures)

    if numGestures >= 1:
        for gesture in gestures:
                        if gesture.type == Leap.Gesture.TYPE_SWIPE:
                            swipe = SwipeGesture(gesture)
                            Swipe_direction = swipe.direction

                            if(self.state_names[gesture.state] == 'STATE_START'):
                                print("Swipe start")

                            if(self.state_names[gesture.state] == 'STATE_UPDATE'):
                                print("Swipe update")

                            if(self.state_names[gesture.state] == 'STATE_END'):
                                print("Swipe end")
                                if(Swipe_direction[0] > 0):
                                    print("RIGHT SWIPE")
                                elif(Swipe_direction[0] < 0):
                                    print("LEFT SWIPE")