[Plugin] Leap Motion - Event Driven

[Joe1029]

Xeno - I am developing for the oculus so all my variables are set up to be attached to the oculus but you can play with those values until you get something that works for you.

Fabianoberlin - You have to install the plugin folder to your project file and NOT the engine folder.

[fabianoberlim]

Fabianoberlin - You have to install the plugin folder to your project file and NOT the engine folder.

It's working in the editor. I just can't make it work to the build project. So I'm assuming that I also need to copy to the project folder where I built it. I did it. But it crashes when I launch.
Or does it automatically copy the "Plugins" folder to the right build location?

"\MainFolder\WindowsNoEditor\Project Folder\Plugins\LeapMotion"

Is that right?

[Joe1029]

I don't know about building the project I havent done that yet.

[Medina2883]

In this documentations its states to use the newest version I have that however none of my blueprint nodes look similar to any of the nodes in the example. the only way to expose Metacarple is after a fingers node and select pointer by id node and after selecting the bones node i can not find a location for that bone? only showing finger tips. also hands never seem to move in or out just side to side and up and down, but the wrist component moves in all proper directions.

[Joe1029]

what are you trying to set up? I havent done anything with the fingers yet. Still have some kinks in the hand rotation

[Medina2883]

I'm having many issues as all the nodes used in these examples are not in the blueprints. the blue pin off the execute doesn't drag off the metacarple node or any of the other finger joints. All i find is stabilized tips for a numbered pointer witch seem to be finger tips but do no move in or out. only up down left and right. also if someone can help me how do you make a varaible from one of the bone joints to call in animation blueprint I have left clicked silly on everything I can think of and can't find a link.

[getnamo]

It's working in the editor. I just can't make it work to the build project. So I'm assuming that I also need to copy to the project folder where I built it. I did it. But it crashes when I launch.
Or does it automatically copy the "Plugins" folder to the right build location?

"\MainFolder\WindowsNoEditor\Project Folder\Plugins\LeapMotion"

Is that right?

Follow the shipping instructions found in the main plugin documentation (github repo). These specify:

The following things must be done, none of them are optional.
1. Add code to project, it doesn't have to do anything but you must have that part so that the plugin gets compiled and linked with the final build
2. Add the following line to your DefaultEngine.ini (found in {Project Root}/Config)
EnabledPlugins=LeapMotion under [Plugins], create this category if missing (part may be optional for a development build). It should look like:

[Plugins]
EnabledPlugins=LeapMotion

3. Package your project, both development and shipping is supported, pick your target and package.
4. In your packaged directory drag the Binaries folder from the plugin into your packaged project folder. E.g. if I have a packaged folder called LeapPluginTest find WindowsNoEditor/LeapPluginTest, this is your packaged project root. Add the binaries folder there.

If you get errors complaining 'Leap Motion' plugin cannot be found, you do not have code in your project.
If you get errors complaining the 'Leap.dll' is missing, you did not drag binaries to the correct location.

[getnamo]

I'm having many issues as all the nodes used in these examples are not in the blueprints. the blue pin off the execute doesn't drag off the metacarple node or any of the other finger joints. All i find is stabilized tips for a numbered pointer witch seem to be finger tips but do no move in or out. only up down left and right. also if someone can help me how do you make a varaible from one of the bone joints to call in animation blueprint I have left clicked silly on everything I can think of and can't find a link.

Grab the latest download from github (link is always at the beginning of this thread), the current version is 0.7.2.

All the documentation found at the github repo and in this thread is up to date. Use events where possible as they filter to only fire when relevant (I.e. if your hand isnt being tracked you will not get any hand/finger events, when you move your hand into view, they will fire), and they will have the contextual data you need available right from the event node.

[fabianoberlim]

First of all, I noticed that I was not using the current build 0.7.2. Updated and fixed all errors inside blueprints. So far so good! Works perfect inside editor.

The following things must be done, none of them are optional.
1. Add code to project, it doesn't have to do anything but you must have that part so that the plugin gets compiled and linked with the final build
2. Add the following line to your DefaultEngine.ini (found in {Project Root}/Config)
EnabledPlugins=LeapMotion under [Plugins], create this category if missing (part may be optional for a development build)

After those steps, I get several errors when I try to compile. Most of the errors are like these:

\plugins\leapmotion\source\leapmotion\public\LeapController.h(36) : error C2039: 'getFrame' : is not a member of 'ULeapController'
plugins\leapmotion\source\leapmotion\public\LeapController.h(34) : see declaration of 'ULeapController'
plugins\leapmotion\source\leapmotion\public\InteractionBox.h(9) : error C2064: term does not evaluate to a function taking 0 arguments
plugins\leapmotion\source\leapmotion\public\LeapFrame.h(9) : error C2064: term does not evaluate to a function taking 0 arguments
plugins\leapmotion\source\leapmotion\public\LeapFrame.h(9) : error C2039: 'fingers' : is not a member of 'ULeapFrame'
plugins\leapmotion\source\leapmotion\public\LeapFrame.h(7) : see declaration of 'ULeapFrame'

And the list goes on for all the header files. I'm not a C++ programmer so I may be making some mistake.
Just to make clear. Do I need to compile and link the LeapSDK with the Unreal code? I don't think so, since the LeapSDK is already inside your build.
What I'm missing?

[fabianoberlim]

[BUG]
There's a bug in the "Time Visibility". If you keep your hands in the leap for 60 seconds, it freezes. Happens when the clock reaches 59 seconds to 60 seconds. It's probably turning the clock to zero and then dividing something.

MachineId:3A2B766347103AC601C101BE480F709D
EpicAccountId:f70334c8adc940bb9f2a7652200b564a

Access violation - code c0000005 (first/second chance not available)

Leap + 202387 bytes
UE4Editor_LeapMotion + 15903 bytes
UE4Editor_LeapMotion + 35027 bytes
UE4Editor_Engine + 1589783 bytes
UE4Editor_Engine + 1651574 bytes
UE4Editor_Engine + 8779958 bytes
UE4Editor_Engine + 8829659 bytes
UE4Editor_Core + 746772 bytes
UE4Editor_Core + 747165 bytes
UE4Editor_Core + 870341 bytes
UE4Editor_Engine + 9060549 bytes
UE4Editor_Engine + 8971673 bytes
UE4Editor_Engine + 8982533 bytes
UE4Editor_Engine + 5590422 bytes
UE4Editor_Engine + 5619206 bytes
UE4Editor_UnrealEd + 1895346 bytes
UE4Editor_UnrealEd + 6486374 bytes
UE4Editor!FEngineLoop::Tick() + 3524 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.5\engine\source\runtime\launch\private\launchengineloop.cpp:2129]
UE4Editor!GuardedMain() + 479 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.5\engine\source\runtime\launch\private\launch.cpp:133]
UE4Editor!GuardedMainWrapper() + 26 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.5\engine\source\runtime\launch\private\windows\launchwindows.cpp:125]
UE4Editor!WinMain() + 249 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.5\engine\source\runtime\launch\private\windows\launchwindows.cpp:201]
UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]

[getnamo]

[BUG]
There's a bug in the "Time Visibility". If you keep your hands in the leap for 60 seconds, it freezes. Happens when the clock reaches 59 seconds to 60 seconds. It's probably turning the clock to zero and then dividing something.

Tested this in blueprint for both finger and hand (finger is a subclass of pointable, the only other class that has timeVisible code), it printed for longer than 60 seconds without issue, so I could not replicate this bug. The code is simply a pass-through for the underlying leap object, so it shouldn't be the reason for a bug. Are you referring to 'getFrame' instead which supports up to 60 frames (valid index 0-59)? Please elaborate what specific setup/steps cause this bug to show up?

First of all, I noticed that I was not using the current build 0.7.2. Updated and fixed all errors inside blueprints. So far so good! Works perfect inside editor.

After those steps, I get several errors when I try to compile. Most of the errors are like these:

And the list goes on for all the header files. I'm not a C++ programmer so I may be making some mistake.
Just to make clear. Do I need to compile and link the LeapSDK with the Unreal code? I don't think so, since the LeapSDK is already inside your build.
What I'm missing?

First of all what build type are you trying to do? Are you packaging your project? (File->Package->Platform->x64/x32) Is it shipping or development build? Please be as specific as you can in terms of what you're doing, for example Launch is not supported due to lack of automatic dll copying in packaging process, but packaged shipping/development builds are.

From my understanding of how the compilation works, for both development and shipping build, the game collapses the plugin into the build and because of this requires the project to have code so that the compiler includes the plugin source in the build. This is a limitation of the shipping process for plugins as far as I am aware. But you should not need to have any additional code or step beyond what is mentioned in the shipping instructions.

Either way, I've tested the shipping instructions several times and they work on my end, perhaps they are not clear enough or you are doing something unexpected, walk me through your packaging process as well the project context (C++ base, blueprint base, leap component added to character subclass/etc).

Also please ensure you DELETE the old plugin(if you have no other plugins, simply delete the Plugins folder from your project) when upgrading, as you may get duplicate classes otherwise which may cause errors when you compile.

[Luis Oliveira]

Hey guys, I'm having a bit of difficulty putting this to work. So, I downloaded the latest leap-ue4-master. I created a pawn blueprint with all the correct nodes (I copied exactly from the instructions), and inserted interface on blueprint props. But when I press play nothing happens!
Any idea of what might be? Thanks!

[getnamo]

Hey guys, I'm having a bit of difficulty putting this to work. So, I downloaded the latest leap-ue4-master. I created a pawn blueprint with all the correct nodes (I copied exactly from the instructions), and inserted interface on blueprint props. But when I press play nothing happens!
Any idea of what might be? Thanks!

You need to add a Leap component in addition to add the interface. Without the component your interface events will never fire!

Two methods of adding a component are:
Option A: Adding Component Directly


Option B: Adding Component through event graph

[Luis Oliveira]

I added through the Option B, and I even ticked all the HMD options because I'm using with the Oculus.
But still, nothing happens.

[getnamo]

I added through the Option B, and I even ticked all the HMD options because I'm using with the Oculus.
But still, nothing happens.

I recommend not using the rift first, but ensure it works by using the regular on-table placement and showing the debug hands. You may be simply not seeing the hand because it is off-screen. Understand that using Optimize for HMD will adjust the positions are rotations with the expectation that you have your leap mounted, essentially requiring you to put on the hmd to preview the hands.