Open cv and Python Scripting with Razer Hydra

[yabix007]

Is it possible to get the hydra data through python. Iam using opencv with an iPhone. Iam trying to implement the razer hydra in python to use it with open cv. How to import pysixense in my OpenCv Scripts? I already installed the hydra sdk. But got no plan how to install the pysixense library? Can I import the freePie hydra plugin in my Phyton Scripts? Thanks in advance.

[AndersMalmgren]

Hi, no Python is only used as a scripting language. The plugins uses c# and currently only run under Windows

[yabix007]

Thank you for the explanation.

I noticed that if i try to acces the hydra update event in FreePie it doesnt do anything. for example

Hydra-Setup und Key-Handling

def bla():
if hydra[0].joyx > 0.5:
keyboard.setKey(Key.D,)

if starting:
hydra[0].enabled = True # Hydra activate
hydra[0].update += bla # Event-Handler for Hydra

#It should press key.D but it doesnt.

#when i put

wiimote[0].acceleration.update += bla

#now it works. I dont undertand it. There for iam forced to use a wiimote for using the hydra. Thats weird

[AndersMalmgren]

hydra and wii are two different plugins with no shared dependencies

[yabix007]

Ah ok good to know. Sadly it doesn't work for me. Is there anything missing in my script?

Here is the Script that only works if I uncomment the Wiimote line:

 # Function that is executed on the update event of the Hydra
 def walk():
     # Control movement based on the current speed
     #if True: #keyboard.getPressed(Key.O)
     if hydra[0].joyx > 0.5:
         keyboard.setKeyDown(Key.D)  # Press "D" for right
     elif hydra[0].joyx < -0.5:
         keyboard.setKeyDown(Key.A)  # Press "A" for left
     else:
         keyboard.setKeyUp(Key.D)  # Release "D"
         keyboard.setKeyUp(Key.A)  # Release "A"
 
     if hydra[0].joyy > 0.5:
         keyboard.setKeyDown(Key.W)  # Press "W" for up
     elif hydra[0].joyy < -0.5:
         keyboard.setKeyDown(Key.S)  # Press "S" for down
     else:
         keyboard.setKeyUp(Key.W)  # Release "W"
         keyboard.setKeyUp(Key.S)  # Release "S"
 
 # When FreePIE starts
 if starting:
 	hydra[0].enabled = True  # Enable Hydra
 	#wiimote[0].acceleration.update += walk 
 	hydra[0].update += walk # why does this not work? What is the correct syntax ?
 

[yabix007]

What's wrong with this line?

hydra[0].update += walk

[JabberwockPL]

I am not (yet) familiar with the intricacies of update procedure, but I have noticed that the Hydra plugin source is missing the line:
public Action OnUpdate { get; set; }
which is present in other plugins, so maybe that is why it does not work.

However, the good news is that the plugin does not require it, as you can just read the data directly. The minimal script might be:

diagnostics.watch(hydra[0].trigger)

Try if it works (as separate script, not IN your script) - the watch tab should show pressing of the trigger of one of the controllers (try both, as Hydra sometimes gets confused which is which).

[MarijnS95]

Since the Python script is supposed to re-run at a regular interval, that's where you can read values (directly outside of the proposed def walk() functions). I don't remember why some plugins have separate OnUpdate callbacks, perhaps because they change their values less frequently than axis values which "should" just be processed every script interval?

[JabberwockPL]

If I understand it correctly, the reason for the use of 'update' is that the scripts, especially involving complex calculations, might be somewhat resource intensive, so it might be better to wait for new data and not perform every operation on old data in every cycle.

[MarijnS95]

It depends; if a certain API doesn't have any sort of update "callback" but only polling methods, the FreePIE engine would have had to compare if anything changed to decide if the OnUpdate delegate should be called (or, as is probably the case with hydra here, not implement that and instead expect the user to read back the value every iteration. If their computation is complex, they can implement caching).

[yabix007]

This script works, if I access the hydra directly. For more complex scripts, the update callback is necessaty i think. So I delete the walk function. It worked

if keyboard.getKeyDown(Key.F3):
	if hydra[0].joyx > 0.5:
		keyboard.setKeyDown(Key.D)  # Press "D" for right
	elif hydra[0].joyx < -0.5:
		keyboard.setKeyDown(Key.A)  # Press "A" for left
	else:
		keyboard.setKeyUp(Key.D)  # Release "D"
		keyboard.setKeyUp(Key.A)  # Release "A"

	if hydra[0].joyy > 0.5:
		keyboard.setKeyDown(Key.W)  # Press "W" for up
	elif hydra[0].joyy < -0.5:
		keyboard.setKeyDown(Key.S)  # Press "S" for down
	else:
		keyboard.setKeyUp(Key.W)  # Release "W"
		keyboard.setKeyUp(Key.S)  # Release "S"

I put this to a walk funtion to it, then it worked properly, too!

def walk():
	if keyboard.getKeyDown(Key.F3):
		if hydra[0].joyx > 0.5:
			keyboard.setKeyDown(Key.D)  # Press "D" for right
		elif hydra[0].joyx < -0.5:
			keyboard.setKeyDown(Key.A)  # Press "A" for left
		else:
			keyboard.setKeyUp(Key.D)  # Release "D"
			keyboard.setKeyUp(Key.A)  # Release "A"

		if hydra[0].joyy > 0.5:
			keyboard.setKeyDown(Key.W)  # Press "W" for up
		elif hydra[0].joyy < -0.5:
			keyboard.setKeyDown(Key.S)  # Press "S" for down
		else:
			keyboard.setKeyUp(Key.W)  # Release "W"
			keyboard.setKeyUp(Key.S)  # Release "S"
walk()

As soon i add

if starting:
	hydra[0].update += walk

instead of walk()
it stops working

[AndersMalmgren]

It depends; if a certain API doesn't have any sort of update "callback" but only polling methods, the FreePIE engine would have had to compare if anything changed to decide if the OnUpdate delegate should be called (or, as is probably the case with hydra here, not implement that and instead expect the user to read back the value every iteration. If their computation is complex, they can implement caching).

Yeah, its a convenient helper for users of freepie. So they dont need to track when updates occour themself.

[MarijnS95]

Hydra uses polling, but still tracks a sequence number to see if the data has changed:

FreePIE/FreePIE.Core.Plugins/HydraPlugin.cs

Lines 143 to 150 in 5f948af

	//This method will be executed each iteration of the script
	for (int i = 0; i < 2; i++)
	{
	var lastSequence = Controller[i].sequence_number;
	Sixense.GetNewestData(i, out Controller[i]);
	if (lastSequence == Controller[i].sequence_number)
	continue;

It does raise an OnUpdate() delegate, but on the plugin and not on the individual controllers:

FreePIE/FreePIE.Core.Plugins/HydraPlugin.cs

Line 175 in 5f948af

OnUpdate();

@yabix007 perhaps you can replace hydra[0].update += walk with hydra.update += walk and see if that works for you?

[yabix007]

This is the error i get when add this:

hydra.update += walk

to the script

'Array[HydraPluginGlobal]' object has no attribute 'update'