[Plugin] Leap Motion - Event Driven

[davide445]

Hi I'm evaluating the usage of Leap Motion for interactive product visualization, wanted to ask how does LP behave with real objects (so to create AR app) where the object itself will occlude part of the hand. it's able to maintain the hand tracking or the sensor need at every time to have free visual to every finger?

[littlewildwolf]

Hey,
we're using the plugin to work with custom gestures in our project.
For one of the gestures I want to use the direction of the fingers, but somehow every finger has the same direction as the index finger.
Do you know what the problem could be?
Thanks in advance.

[getnamo]

I was building my own swipe gesture, because the built in one was giving strength values only if the hand was moving within a certain velocity. Too fast or too slow wouldn't give any gestures from the leap frame reference and the Interface 'evnet swipe gesture detected' wouldn't execute or freeze the values.

Is there any way to adjust the threshold of the a built in gesture?

There's nothing built in that provides that flexibility, looks like you'll have to go custom. In general it is recommended nowadays to use direct physical interaction with things rather than general gestures, but if you wish to use general gestures, swiping is pretty easy to do manually.

I recommend taking the finger tip position and storing it each tick and calculating the velocity manually from Velocity = Distance/DeltaTime each tick. Then if the velocity vector breaches a certain Vector.Size() threshold while being within e.g. <30 degrees within your desired swipe direction normal, consider it a swipe. To get angles between vectors you can use the Dot product between your velocity normal and the direction you're interested in divided by their magnitude. i.e.

Angle = ACOS((Vector1 dot Vector2) / (Vector1.Size() * Vector1.Size() ))

[BOBtheROSS]

[...] Out of curiosity what use case are you using this particular function for?

I was building my own swipe gesture, because the built in one was giving strength values only if the hand was moving within a certain velocity. Too fast or too slow wouldn't give any gestures from the leap frame reference and the Interface 'evnet swipe gesture detected' wouldn't execute or freeze the values.

Is there any way to adjust the threshold of the a built in gesture?

[getnamo]

Hi,
It's me again with another bug.
Seems like the Tip Velocity of the Leap Finger References get the Camera offset added in HMD mode. Plz fix

The API for this will be changing completely in the upcoming plugin. It will likely not expose velocity values to keep a smaller and more maintainable footprint. In return it should have better high level interaction support. Out of curiosity what use case are you using this particular function for?

Also if you're interested, PM me your github username to get preview access to the new plugin.

[BOBtheROSS]

Hi,
It's me again with another bug.
Seems like the Tip Velocity of the Leap Finger References get the Camera offset added in HMD mode. Plz fix

[getnamo]

I've seen some discussion here about the lag in the tracking being caused by the use of time warping, but no clear solution being offered.
https://community.leapmotion.com/t/u...latency/5791/3
https://github.com/getnamo/leap-ue4/issues/16
https://github.com/getnamo/leap-ue4/issues/9

Is there a clear solution that I can use to have the same quality of tracking that I get in Unity? It would be great if I could get this in Unreal because Unreal kicks ***.

Thanks!

There's a currently private preview plugin available for people willing to give some feedback which already has this fixed along with some other cool features . PM me your github username and I'll add you to it.

[funkmeisterb]

I've seen some discussion here about the lag in the tracking being caused by the use of time warping, but no clear solution being offered.
https://community.leapmotion.com/t/u...latency/5791/3
https://github.com/getnamo/leap-ue4/issues/16
https://github.com/getnamo/leap-ue4/issues/9

Is there a clear solution that I can use to have the same quality of tracking that I get in Unity? It would be great if I could get this in Unreal because Unreal kicks ***.

Thanks!

[BOBtheROSS]

I found a bug considering the Anim Body component. The function 'Enable' (used in LeapHandsActorBase in the function ShowHandsBasedOnTracking) for the Anim Hand references can sometimes give a revesed situation. The function state that a left hand is being tracked when it is a right hand (wich can correctly dertermined by other values like the hand ref from the 'HandMoved' interface event). The Same happens on the variable 'Alpha' of the left and right Hand references. This bug causes the Skeletal Mesh hands to freeze in these situations.

[funkmeisterb]

The current v2 plugin uses two meshes, one for each hand, check the blueprint to ensure both of these are setup to work with your Flex objects. e.g. LeapRiggedEchoHandsActor.uasset

Thank you for your answer. What I had to do was indeed to add extra capsules to the finger meshes and to make sure that their collision system was set to block Flex objects.

I have another problem now: the hand meshes appear at the wrong position now. In the screenshot below, the hand is right in front of my character, and it appears closer to his head.


I have tried disabling the plugin/restarting UE4/reenabling the plugin/restarting UE4 and the problem is still there. Even when I create a new project and follow these instructions I still get the error.

This problem appeared when I double-clicked the LeapEchoHands_AnimBlueprint animation blueprint in my project. Before opening it, UE4 told me asked me to rebuild the mesh (or something to this effect) and I clicked yes. Now I can't get back to the working setup of the leap hands.

Interestingly enough, my project is source controlled and I do not see any changes to the LeapEchoHands_AnimBlueprint file.

Any ideas on how to restore the working leap animations?

[getnamo]

Hello,
I'd like to know if there is some way to capture one hand on top of the other hand while using leap.
I've been stuck on this for a while now and would appreciate any help Thank you.

Do you mean when you occlude one hand with the other? The current leap tracking should be able to still capture the top hand when it is visible, but the other hand will be physically occluded from the cameras. You may wish to elaborate what you wish to specifically accomplish.

Hi, I sorry to brother you , I need use this plugin in UE4 c++ Project ，but in the github page,I find you "C++ how to" is not upgrade .Is there any possible to renew this thread recently? [MENTION=548]getnamo[/MENTION]

PM me your github username and I'll add you to the preview plugin which has C++ support.

Hi, thank you for this great plugin.

I have a question about using this plugin with the Flex branch of Unreal: how do I make the left hand work with Flex objects?
I am using Flex UE4 + LeapMotion + Oculus DK2 to accomplish something similar to this: https://www.youtube.com/watch?v=Fv9QGPCppwE.

I have created a new Game Mode blueprint that uses the LeapFloatingHandsCharacter pawn, as per the instructions.

When I try to interact with a flexSphere, only the right hand works:
[ATTACH=CONFIG]148882[/ATTACH][ATTACH=CONFIG]148883[/ATTACH]

Interestingly, the left hand collisions work with non-Flex meshes.

Does anyone have an idea what is wrong? Thanks

The current v2 plugin uses two meshes, one for each hand, check the blueprint to ensure both of these are setup to work with your Flex objects. e.g. LeapRiggedEchoHandsActor.uasset

[jacksparow]

Hi, I sorry to brother you , I need use this plugin in UE4 c++ Project ，but in the github page,I find you "C++ how to" is not upgrade .Is there any possible to renew this thread recently? [MENTION=548]getnamo[/MENTION]

[funkmeisterb]

Hi, thank you for this great plugin.

I have a question about using this plugin with the Flex branch of Unreal: how do I make the left hand work with Flex objects?
I am using Flex UE4 + LeapMotion + Oculus DK2 to accomplish something similar to this: https://www.youtube.com/watch?v=Fv9QGPCppwE.

I have created a new Game Mode blueprint that uses the LeapFloatingHandsCharacter pawn, as per the instructions.

When I try to interact with a flexSphere, only the right hand works:


Interestingly, the left hand collisions work with non-Flex meshes.

Does anyone have an idea what is wrong? Thanks

[m4k]

Hello,
I'd like to know if there is some way to capture one hand on top of the other hand while using leap.
I've been stuck on this for a while now and would appreciate any help Thank you.

[a_tu]

This was fixed in a pull request a while back:
https://github.com/getnamo/leap-ue4/...abed9a09886d35

it was an oversight

oh, my bad, no good to use an outdated plugin version. thank you