[Plugin] Leap Motion - Event Driven

[getnamo]

Yup its a C++ project. Ive added the dependency with "LeapMotion". I've manage a workaround where i created a copy of whatever leap motion character blueprint i need and change the parent of it to my custom own character class so i can modify it without affecting the source plugin. It works OK.

Another thing was the skeleton for the floating hands shows that it cannot find a skeletal mesh for that specific hand (left or right). I wanted to added Mesh Sockets but everytime i do it crashes. Im just using Bone Name at the moment.

This is an image of the error im getting:

http://imgur.com/a/UXwCD

I went into the file, LeapGestures.h, and added "LeapEnums.h". Those error went away but another one came up saying "'Leap' is not a class or namespace name"

Image here:

http://imgur.com/a/v1MSu

Thanks for your help [MENTION=548]getnamo[/MENTION]

For the skeletal mesh, can you show me a screenshot of the error it's showing?

Regarding Leap.h, haven't used this plugin in C++ for a long time, it's due for a rewrite to make it more streamlined TBH. It appears the Leap.h header is exposed somewhere where it shouldn't be, somehow the forward declarations aren't doing their job.

I believe your best route atm is to use the workaround, I'll make sure to test the rewrite, when it happens, for C++ use cases.

[sonnyday_]

Is this is a C++ project? Have you added LeapMotion as dependency in your project build.cs?

Yup its a C++ project. Ive added the dependency with "LeapMotion". I've manage a workaround where i created a copy of whatever leap motion character blueprint i need and change the parent of it to my custom own character class so i can modify it without affecting the source plugin. It works OK.

Another thing was the skeleton for the floating hands shows that it cannot find a skeletal mesh for that specific hand (left or right). I wanted to added Mesh Sockets but everytime i do it crashes. Im just using Bone Name at the moment.

This is an image of the error im getting:

http://imgur.com/a/UXwCD

I went into the file, LeapGestures.h, and added "LeapEnums.h". Those error went away but another one came up saying "'Leap' is not a class or namespace name"

Image here:

http://imgur.com/a/v1MSu

Thanks for your help [MENTION=548]getnamo[/MENTION]

[getnamo]

[MENTION=548]getnamo[/MENTION] i tried adding LeapController.h to my character class and its giving me this error: 'Leap': is not a class or namespace name. Do you know whats wrong with it?? Thanks

Is this is a C++ project? Have you added LeapMotion as dependency in your project build.cs?

[sonnyday_]

[MENTION=548]getnamo[/MENTION] i tried adding LeapController.h to my character class and its giving me this error: 'Leap': is not a class or namespace name. Do you know whats wrong with it?? Thanks

[getnamo]

Hey Getnamo,

Yeah, everything works, it's just the grabbing with the floating hands I can't seem to figure out.
Basic-rigged character works fine, but when I try to apply the grabbing to the floating hands it stops working when using the does implement interface.
Is it because there is no real mesh inside of the floating hands but a child actor?

So was just wondering how Catonice did his fix to get the grabbing working in the floating hands.

Thanks for the work on the plugin, really impressive to get your hands in VR.

I believe you're right, the floating hands are built to support multiple types so the actual mesh will be in one of the child blueprints, open the floating hands character blueprint to confirm. You can also just place the floating hands actor into any blueprint of your choice and it should all just work out of the box.

e.g. the Plugins/LeapMotion/Content/Blueprints/Rigging/FloatingHands/LeapRiggedEchoHandsActor.uasset

[Sequaris]

Hey Getnamo,

Yeah, everything works, it's just the grabbing with the floating hands I can't seem to figure out.
Basic-rigged character works fine, but when I try to apply the grabbing to the floating hands it stops working when using the does implement interface.
Is it because there is no real mesh inside of the floating hands but a child actor?

So was just wondering how Catonice did his fix to get the grabbing working in the floating hands.

Thanks for the work on the plugin, really impressive to get your hands in VR.

[getnamo]

Hi,
Thank you for your work.
I was wondering if there's any way to animate my own rigged hands using the location and rotation data provided by the leap plugin.
Has anyone been able to do this using blueprints? I would appreciate the help.

Thanks !

This is done in blueprint inside the plugin itself, feel free to look into e.g. LeapEchoHands_AnimBlueprint.uasset to see examples of how it is done. For a reference on how the whole setup works see

https://github.com/getnamo/leap-ue4#...etup-and-notes

Hi Catonice,

Could you explain your fix a bit more in detail?
If possible maybe show your complete blueprint? Can't seem to get the floating hands to work...

Thanks !

Have you had a chance to look through https://github.com/getnamo/leap-ue4#...ged-characters and the main documentation in general?

[Sequaris]

Hi Catonice,

Could you explain your fix a bit more in detail?
If possible maybe show your complete blueprint? Can't seem to get the floating hands to work...

Thanks !

Thanks for the reply getnamo! I've figured out a work around! I instead placed the blueprints inside LeapRiggedEchoHands, the child actor for LeapHands iirc (I'll check this tommorow to confirm but I thought I'd writed quickly for now). Once I did that I got it working. So for anyone who has the same problem, place it in the child actor and cast your grab variable from the your character to that bp to check if grabbing. I'll post a screenshot of my bp later. Apologies if I explained incorrectly here.

EDIT: So just to clarify, instead of placing your bp functions and nodes such as pickupIfEmpty inside the BP_FloatingHands you move it to LeapRiggedEchoHands actor bp. I know there are better ways to do these things but I didn't have a lot of time :P
[ATTACH=CONFIG]110542[/ATTACH]

[tofmed]

Hi,
Thank you for your work.
I was wondering if there's any way to animate my own rigged hands using the location and rotation data provided by the leap plugin.
Has anyone been able to do this using blueprints? I would appreciate the help.

Thanks !

[kungfukoi]

Thanks for the reply [MENTION=548]getnamo[/MENTION]!

I'll give it a try and let you know how it goes.
( because I KNOW you're on the edge of your seat )
:-)

[getnamo]

I'm looking for information on how to remap the coordinate system of the Orion Hands.
Looking for where I can control/modify position relative to screen space.

Thank you.

The plugin automatically remaps the coordinate system from Leap space to UE space.

That said, if you use the convenience hands you can modify the coordinate by just parenting a scene node; if you use blueprint custom or C++ you can modify the output you receive from the plugin by multiplying the output by a transform. Optionally you can modify this file: https://github.com/getnamo/leap-ue4/...aceUtility.cpp to change the coordinate system transform globally for all output from the plugin.

[kungfukoi]

I'm looking for information on how to remap the coordinate system of the Orion Hands.
Looking for where I can control/modify position relative to screen space.

Thank you.

[getnamo]

Thanks for the reply! I'd actually poked around the plugin code myself and came to a similar conclusion.

One thing to note is that simply making all the functions BlueprintNativeEvents means that any C++ classes that extend ILeapEventInterface must explicitly provide definitions for all the BlueprintNativeEvents in the interface. For me this means seventeen empty stub functions, for the five or so events I actually care about. Could be worse, but still pretty messy to deal with. Trying to put stub definitions inside of the interface doesn't work, as this results in a compiler error about being unable to instantiate abstract classes. I assume this is unreal trying to enforce interfaces as function declaration only.

I was thinking about other solutions, but I couldn't think of any that felt strictly 'better'. There's splitting up the LeapEventInterface into several smaller interfaces (hand, finger, gesture, passthrough?), but that'd require some significant changes in LeapController, and it could be disruptive for existing projects. On the plus side, it could result in fewer extraneous event calls, depending on how its implemented. Another possibility would be to use the regular C++ virtual function for native implementation, as that can have an overridable implementation in the interface, and then wrap that and the BlueprintImplementable function in a function:

.h

UFUNCTION(BlueprintNativeEvent, Category = "Leap Interface Event")
	void OnLeapHandMoved(ULeapHand* hand);
	virtual void OnLeapHandMoved_Native(ULeapHand* hand);
	void LeapHandMoved_Exec(ULeapHand* hand)

.cpp

void OnLeapHandMoved_Native(ULeapHand* hand) {
	//stub function so implementation is optional};

void LeapHandMoved_Exec(ULeapHand* hand) {
	OnLeapHandMoved_Native(hand);
	ILeapEventInterface::Execute_OnLeapHandMoved(this, hand);//not sure if this would work, havent tested
}

But then that removes the possibility of doing things like defining an event in C++ and then overriding it in a blueprint child.

I think stubs is the correct way to go for now, it might be a bit annoying but it's harmless. May not be very clean, but being explicit is very C++

I had the plugin working but now with a new project in 4.11.2 I am getting this error

"Missing or incompatible modules in LeapMotion plugin"

Any ideas what I am doing wrong?

EDIT - Nevermind I guess the plugin got built in the engine? Or maybe I put it in there. Not sure.

Has anyone had issues in 4.13? It seems to be working fine...?

Yep since 4.11 the community plugin is the official one and is now included in each engine release.

[serbaside]

I had the plugin working but now with a new project in 4.11.2 I am getting this error

"Missing or incompatible modules in LeapMotion plugin"

Any ideas what I am doing wrong?

EDIT - Nevermind I guess the plugin got built in the engine? Or maybe I put it in there. Not sure.

Has anyone had issues in 4.13? It seems to be working fine...?

[jlin98]

Thanks for the reply! I'd actually poked around the plugin code myself and came to a similar conclusion.

One thing to note is that simply making all the functions BlueprintNativeEvents means that any C++ classes that extend ILeapEventInterface must explicitly provide definitions for all the BlueprintNativeEvents in the interface. For me this means seventeen empty stub functions, for the five or so events I actually care about. Could be worse, but still pretty messy to deal with. Trying to put stub definitions inside of the interface doesn't work, as this results in a compiler error about being unable to instantiate abstract classes. I assume this is unreal trying to enforce interfaces as function declaration only.

I was thinking about other solutions, but I couldn't think of any that felt strictly 'better'. There's splitting up the LeapEventInterface into several smaller interfaces (hand, finger, gesture, passthrough?), but that'd require some significant changes in LeapController, and it could be disruptive for existing projects. On the plus side, it could result in fewer extraneous event calls, depending on how its implemented. Another possibility would be to use the regular C++ virtual function for native implementation, as that can have an overridable implementation in the interface, and then wrap that and the BlueprintImplementable function in a function:

.h

UFUNCTION(BlueprintNativeEvent, Category = "Leap Interface Event")
	void OnLeapHandMoved(ULeapHand* hand);
	virtual void OnLeapHandMoved_Native(ULeapHand* hand);
	void LeapHandMoved_Exec(ULeapHand* hand)

.cpp

void OnLeapHandMoved_Native(ULeapHand* hand) {
	//stub function so implementation is optional};

void LeapHandMoved_Exec(ULeapHand* hand) {
	OnLeapHandMoved_Native(hand);
	ILeapEventInterface::Execute_OnLeapHandMoved(this, hand);//not sure if this would work, havent tested
}

But then that removes the possibility of doing things like defining an event in C++ and then overriding it in a blueprint child.