Razer Hydra Plugin

[n00854180t]

There are two graphs in the animation blueprint - the Event Graph, and the Anim Graph. The first is the one you gave screenshots of and where you're setting the variables. The second, the Anim Graph, is where you want to use the Two-Bone IK node or the FABRIK nodes to use those positions to transform the positions of the hands.

You don't need to mess around with the character blueprint - while input is often put there, for the Hydra, it's in the Player Controller and it's already getting into the Anim Blueprint's Event Graph from there. You just need to use the variables in the Anim Graph.

[aialexander]

Okay, cool! So that means that the problem I'm having is being caused by something else. I also have been getting this error whenever I play the game in the editor to test if the hydra is working.



Has anyone else gotten this error? I've tried disconnecting the Set "Is in Air?" node and just skipping right to setting speed, but I'll get a similar editor regarding the hydra component. Any idea what I've done wrong here?

[n00854180t]

Your "Hydra" variable in the animation blueprint Event Graph is None/null - you probably need to set it in the controller. Personally I set the position/rotation variables in the controller and then use that in the animation blueprint, rather than trying to access the Hydra from there.

[getnamo]

Your "Hydra" variable in the animation blueprint Event Graph is None/null - you probably need to set it in the controller. Personally I set the position/rotation variables in the controller and then use that in the animation blueprint, rather than trying to access the Hydra from there.

I second this approach, it gives a better input indirection meaning more abstraction from input source. When you have decently abstracted input, your gameplay mechanics are less affected by the specific input e.g. hardware and your game logic is more adaptable to new types of input of the same class.

[aialexander]

IT WORKS!!!! (Commence spaz)! Thank you!

[aialexander]

Now there's just the problem of the hand positions being underscaled for some reason. The rotation seems to be working alright, but the location is hardly moving at all.

[chadyo]

Is there any plans to put together a full tutorial on how to attach the hydra positions to a characters hands? I've tried following this thread using both IK and FABRIK but I keep getting stuck with arms that don't bend at the elbows and hands that don't really seem to move in the Z direction and don't rotate. I'm thinking I'm missing something in the IK/FABRIK setup which seems to lack documentation on the UE4 side. Any help would be very much appreciated!

[n00854180t]

Is there any plans to put together a full tutorial on how to attach the hydra positions to a characters hands? I've tried following this thread using both IK and FABRIK but I keep getting stuck with arms that don't bend at the elbows and hands that don't really seem to move in the Z direction and don't rotate. I'm thinking I'm missing something in the IK/FABRIK setup which seems to lack documentation on the UE4 side. Any help would be very much appreciated!

I do plan on doing a full tutorial, but it's going to take a bit of time as I need to port it out of my game and into the generic UE4 blueguy.

[chadyo]

I do plan on doing a full tutorial, but it's going to take a bit of time as I need to port it out of my game and into the generic UE4 blueguy.

Great, looking forward to it!

[aialexander]

By the way, earlier in the thread when you guys mentioned you were using "feel good" variables, what did you mean by that?

[getnamo]

By the way, earlier in the thread when you guys mentioned you were using "feel good" variables, what did you mean by that?

Just means these are values with no basis to a proper model. Instead of deriving proper values that are based on model or user dynamics, they are values that are determined experimentally and may not be valid for a wide range of use cases. If you know the values are valid over their expected use case, then they are accurate, but if, for example, they were just calibrated only to how my real body moves, then they may not be valid for a wider set of users.

In sum it means, use those values with care as they may work now for the current setup, but may not be valid for every use case.

[n00854180t]

To put it another way the values are "tuned" to the particular character and player that we've been testing with (in my case, my game's character and my body parameters (height/arm reach)), but there is no generalized system for determining those values - they're just hardcoded.

So what needs to happen is a more in depth calibration step where those hardcoded values are calculated based only on the available parameters. One reason I haven't set that up yet is that the Oculus profile height is not exposed to UE4. Shouldn't be hard to add a console command for it, but that's more time spent compiling and stuff for a minor change.

[aialexander]

So I have the FABRIK nodes set up in the anim graph for my character, but I seem to be having some issues with the IK. For some reason by arms are completely stiff to the point where when I move them in both the z and the y axis, if the arm is facing forward, it will translate on the z axis instead of the y axis. So translating on the z axis and the y axis will sometimes do the same thing. Does anyone happen to know what could be causing this?

[aialexander]

So I realize it might be a little forward of me to ask this, but if anyone has this working to some degree the way it should, would you mind sharing your project? I would like to see how you put everything together to get the hydra working with the hands moving in the right direction and the elbows bending properly. It would be very helpful to me as I also learning more and more about Blueprints while working on this.

[n00854180t]

@aialexander, I've had several requests of an example recently, but don't have anything that's readily shareable, so I'm going to try and get what I have ported over into the VR game template so that there's something I can point to. Hopefully by sometime tomorrow or maybe early in the week.