VR Expansion Plugin

[mordentral]

@TQwan

Hi,

I’m trying to use the skeletal mesh weapon from the epic templates.
In your example template you use a Static Mesh Actor as a gun.
I tried to duplicate code, however I think your AGrippableSkeletalMeshActor should never work.

At some point GripMotionControllerComponent.cpp calls method:

snip, removed due to length from my quote

I also modified the Weapon so that the Skeleton bones are exactly the same as the Static Gun.
In the new skeleton I added the VRGrip sockets. Next to that I created a new Physics asset.

The current status is that the hand now grips the BP Actor that contains the Skeletal Mesh Actor and fire’s the weapon, however the weapon location and rotation are never updated (even though all settings are exact the same as the Static Mesh Gun.
The fire does seem to work.

Note: The drop seems to work, since when the motion controller is moved away the weapon stops fireing.

Concluding:

Grab animations work. (hand open / closed animations are being applied when hovering or grabbed)
Drop works (kinda, the weapon physics don’t seem to be applied (it keeps floating where it spawn), but it stops firing when moving to far from the weapon).
Fire weapon start/stop works.
Location / Rotation do not work for Grippable Skeletal Mesh Actors.

So:

1. Do you have an example using a Skeletal Mesh Weapon?

2. Where is the motion controller rotation/location applied to the grabbed actor?

3. Maybe there is another mobility check I missed.

–Other notes–
I noticed GrippedBoneName, OptionalBoneToGripName and OptionalSnapToSocketName is always None for both Gripable Static / Skeletal Mesh Actors, however socketTrans seems to be set so I guess it’s not really a problem.

I’m currently using VR Example Plugin template of 16-03-2018 (f62d5b04063c091e809a4664d4b5d3c4eabd0d0d)

Scenecomponents auto set mobility to movable, the chain of inheritance goes ActorComponent->SceneComponent(sets movable)->PrimitiveComponent(hides movable category from BP)->SkeletalMeshComponent.

Technically I don’t have to set mobility in the static mesh component either since it is already defaulted to true. By default all primitive components hide the Mobility category, Epic specifically goes in with static mesh components and shows it again so it can be set in blueprint " ShowCategories=(Mobility)".

In the template, literally just adding a GrippableSkeletalmeshActor, setting it to the gun and applying its physics body, it will pick up and work fine. There are also several users that ONLY use skeletal meshes for grips in their games.

For where the rotation and location are applied, it is on TickGrips in the motion component, it pre-calculates some transforms and then applies movement logic to the held objects (unless a custom grip type, then it sends an event off to the object to handle it, itself).

GrippedBoneName is set if the trace hits and the object is set to be per bone grippable in the template, otherwise it just grips as the actor itself (root bone).

OptionalSnapToSocketName is kind of legacy at point as it is less flexible, directly passing in the calculated socket transform is better as it allows controller profile editing and some other things, at some point I will remove it, but it still “works” fine for singleplayer.