[Plugin] Leap Motion - Event Driven

[Doug E]

Hey JasonKoch-

If you create a custom game mode (Content Browser -> Add New -> Blueprint Class -> Game Mode) you can set that game mode in the world settings. Once you've done that the extended options for the selected game mode will become editable and you can change the character pawn.

Cheers

Doug

[JasonKoch]

Hey guys.

This may seem ridiculously retarded, but when I try and adjust the world settings game mode to set the character to LeapRiggedCharacter, the character tab is locked. I'm new to this editor, and I may be in the wrong place completely, but it seems to be the same as what the tutorial pic suggests. There is no direct information as to where to cange this and I don't know how to unlock the tabs. Can someone please be very specific as to where I should change the settings in the first step.

Thanks guys.

[bwiklund]

After creating a fresh project, dropping the folders in, and restarting unreal:

The following modules are missing or built with a different engine version:

UE4Editor-LeapMotion.dylib

Would you like to rebuild them now?

When I click OK, it fails with:

LeapPassthroughTest could not be compiled. Try rebuilding from source manually.

This on OSX 10.10.1, UE4.7.3, Leap SDK 2.2.3

[Rasa]

Hi Getnamo,
In Default third person, I have setup the Input setting for Moveforward and turn rate to Leap right Palm Pitch and Leap right Palm Yaw, so now in certain stage I have control the character in idle stage but it is difficult to become idle while giving gesture, Is there way to become character idle by leap geasture.

I tried Disable and Enable Input but Disable works well after that Enable doesn't works, gestures doesn't detect.

[san]

Pretty impressive you got this third party plugin working so well!
I'm curious why there is are Windows and OSX versions of the plugin but none for Linux. Is it simply the lack of resources and/or exerience in that area or are there fundamental issues that need to be resolved?

[getnamo]

i see you fix the finger rotation problem. That nice.

Yep the finger rotation problem was caused by using the bone direction vector which by itself doesn't have enough information to determine rotation properly (two vectors would be enough, or a rotation matrix). So I switched to using the basis matrix which the leap api provides for each bone, from which you can derive a UE rotator that behaves as expected. This problem was also present in the elbow rotation, which was fixed in the 0.9.1 update. I feel like playing with these plugins have really improved my understanding of vector and matrix math, gotta love it!

when i move the head with a hand in front i see the hand move slighty when must be stopped.

official plug-in have same problem.

I rely on the same tracking data that comes out of the leap, so it makes sense for us to have the same problem. I believe there is a slight lag between input, so if you move your head quickly it will take a little bit of time (much less than a second) for the hands to get fully in sync with the updated viewpoint.

This is, I believe, a physical limitation of the current leap tracking method, as they need a few compute cycles to determine the hand position and posture. They are quick, but not oculus quick. You can maybe improve this with some motion prediction, but that would be a pretty tough project.

[knack]

i see you fix the finger rotation problem. That nice.

when i move the head with a hand in front i see the hand move slighty when must be stopped.

official plug-in have same problem.

[knack]

thanks getnamo again! havent time for try since 4.6. Will try today.

[getnamo]

It looks like your leap is in robust mode's half-vertical-resolution state in that last gif.

If you add the line to your config.json in your ProgramData->Leap Motion folder, it should avoid this...

Interesting, the leap image mode does sometimes resize automatically to a worse quality, didn't know we had control over it. Will try your recommendation

[zalo]

It looks like your leap is in robust mode's half-vertical-resolution state in that last gif.

If you add the line

"robust_mode_enabled": false,

to your config.json in your ProgramData->Leap Motion folder, it should avoid this...

[getnamo]

Hey getnamo,

We just want to thank you for your plugin. Seems to work excellent and it's just incredibly easy to integrate.

In case you didn't know, we're developing a soft-body physics engine plugin for Unreal Engine 4, check out our thread here: https://forums.unrealengine.com/show...lug-in-for-UE4

So our leap motion devices came in today and we really couldn't wait to try and see how it integrated with our own soft-body physics engine, so we threw together a quick showcase using your plugin. Pretty surprised to see how easy it all was Here's the result:

...

Keep up the good work!

Love this frog video, awesome work!

Is there anyway to make the Debug Sphere to trigger with trigger box?
(I'm quite new and don't know how to interact with 3D models in the blueprint though, so I use debug sphere instead.)

Your best bet would be to attach a capsule or box to the interaction location and that for the trigger interaction. You can also add components to the convenience rigged content bones or alternatively you can instead use the official plugin which contains rigged content with physics. Finally this plugin will get some physics convenience components added to it eventually, but that may be some time.


Documentation for 0.9

How to use the convenience rigged passthrough character:
1) Select the LeapPassthroughCharacter as your pawn and VRPlayerController as your controller

2) Use the included gesture to transition from VR to AR! (Optionally make your own method, see below for details)





This updates the convenience content relationships to the following


What this setup gives you in flexibility is that you have many entry points from which to modify any aspect of the rigging. E.g. If you wish to change post process material being used you would change it in the PPChanger blueprint while still retaining every other functionality. Or if you want to adjust the default mode offset (where your leap is in relation to you when place on the table) you would modify the LeapAnimBodyConnector component which specifies its location. If you want to use your own skeletal mesh, simply replace the mesh, but retain the anim blueprint (use animation retargeting if you're using different skeletons). In fact the rigging setup doesn't even need the leap motion to work, any input which would change the AnimBody skeleton to whatever pose you wish to attain would have the same rigged behavior. The setup is the beginning part of a BodyInput plugin which will support a similar setup for various VR inputs in the future.

Attaching Passthrough to your own Character
If you attach a LeapBodyConnectorWithPassthrough actor as a child actor you will automatically get an AnimBody that will sync with your leap movements. To enable passthrough you call this function in some initializer such as a BeginPlay. You have the option of disabling the pinch + swipe up/down gesture for transitions.



If you wish to make your own transitions you can call ShowPassthrough on the connector.



which is simply a float parameter change in the post process material.



If you want to see how this has been implemented, browse the LeapAnimBodyConnectorWithPassthrough blueprint.



In there you will notice we obtain 4 image pointers, one for each distortion and one for each raw image. These are then fed to a PostProcessChanger (PPChanger) convenience component which handles adding a custom blendable with the correct links to the character camera.



this then uses the following post process material to render the images appearing correct for the DK2, compensating for both fish-eye lens distortion in the leap cameras and the rift warp.



This would also be where you would duplicate and modify the material to produce interesting effects such as depth-based blending or custom depth drawing (3d element overlay in real world)




The plugin still supports all the earlier feature sets so if you wish to build your own bind, you have all the tools available.

Let me know if this has been helpful, if you would do things differently, or general questions/feedback. Hope you guys like it!

[Tony Tong]

Is there anyway to make the Debug Sphere to trigger with trigger box?
(I'm quite new and don't know how to interact with 3D models in the blueprint though, so I use debug sphere instead.)

[getnamo]

Update to 0.9
-Binaries updated to UE4.7
-Added properly HMD warped image passthrough support through both
materials and a convenience character (LeapPassthrougCharacter)
-128bit texture support resolved for Distortion textures. Use Distortion
for proper float data, use DistortioUE to visualize the texture for
debug purposes.
-Optional content moved into plugin, delete if you don't use it and wish
to save space
-Rigging update to be more loosely coupled. Character anim blueprint
only depends on AnimBody obtained through a simple and safe
AnimBodyInterface
-Rigged character finger rotation bug fixed
-Updated leap bind to 2.2.3, much improved tracking gained.
-Added R->Reset position to rigged characters, change key bind to
reflect own bindings

This post will be updated at a later date with more information/tutorial.
Edit:

Update to 0.9.1
-Cleaned up inheritence structure, LeapAnimBodyActor renamed to
LeapAnimBodyConnector. Added Passthrough sub-class
-LeapPassthroughCharacter now contains the subclass. Rigged characters
contain no passthrough code
-Fixed elbow rotation bug

See my next post below for more documentation on the new passthrough feature.

[seandennis]

I wonder who will be the first to make VR poker/ black jack game with oculus and leap motion. including multi-player

[Tendr Dynamics]

Hey getnamo,

We just want to thank you for your plugin. Seems to work excellent and it's just incredibly easy to integrate.

In case you didn't know, we're developing a soft-body physics engine plugin for Unreal Engine 4, check out our thread here: https://forums.unrealengine.com/show...lug-in-for-UE4

So our leap motion devices came in today and we really couldn't wait to try and see how it integrated with our own soft-body physics engine, so we threw together a quick showcase using your plugin. Pretty surprised to see how easy it all was Here's the result:

Keep up the good work!