feature(Interaction): improve grabbing

Here are some problems I encountered with the grabbing behavior.

1. Search for UInteractable at parent component if hit actor is a child actor

Setting: A parent actor that contains a child actor, e.g. a WIM that contains a smaller representation of a real object as child actor. Problem: Currently it is not possible, that the parent actor is grabbable, if the child actor is not grabbable. Reason: In GrabComponent.cpp a sphere cast is done to find objects close by. If the sphere cast hits the child actor we search for UInteractableComponent in the child actor, which we do not want to be grabbable, therefore there is no UInteractableComponent.

Solution:

• Provide a way to specify the actor that should move (parent or child etc.). Since this might be an edge case, I just used a boolean flag for now that per default behaves like before.

2. Expose a TryRealease() function that releases the currently grabbed object

3. InteractableComponent can broadcast OnActionStart events without requiring hover to be called first.

This is a little bit misleading. I kind of expect, if I subscribe to the OnActionBegin event in the grabbing component, that this is called after the object has successfully been grabbed. I now added OnBeginGrab/OnEndGrab events returning the grabbed object and a IsObjectGrabbed() function

Discussion: I think in general, OnActioStart events should only be called if we currently hover.

4. GrabbablesInRange.AddUnique() in GrabComponent.cpp

An actor can have multiple static meshes, that return a collision, therefore we would add the same actor multiple times which is probably unwanted behavior.

5. Added option to only grab closest object

changed milestone to %Consistent Interaction Base

added Discussion Feature labels

requested review from @marcel.krueger

assigned to @david.gilbert

marked this merge request as draft

changed title from feature(Interaction): adds flag to only grab closest actor, adds flag to... to Draft: feature(Interaction): improve grabbing

changed the description

added 27 commits

• 34691cfb...dc57f757 - 26 commits from branch vr-vis/VR-Group/unreal-development/plugins:dev/5.3
• 02ab0e9c - Merge branch 'dev/5.3' of...

Compare with previous version

added 1 commit

• 6caecdb5 - fix(interaction): removes unused/broken include after renaming

Compare with previous version

added 1 commit

• a3654dfb - fix(interaction): removes unused/broken include after renaming

Compare with previous version

added 3 commits

• a3654dfb...9bd56300 - 2 commits from branch vr-vis/VR-Group/unreal-development/plugins:dev/5.3
• 5d6bee08 - Merge branch 'dev/5.3' into 'dev/5.3'

Compare with previous version

marked this merge request as ready

marked this merge request as draft

I still have to check for clang format will do it when I am back in the office.

Can you also rephrase point 3? So currently it is possible that OnAction is called without OnHover being called first? When does it happen ? Depending on the circumstances we should probably discuss if we want the OnHover first or just supress OnAction.

Discussion w.r.t to childs being grabbable. We basically have 4 possibilities:

G = Grabbable 
N = Not Grabbable

# Parent  Child Behaviour 
1 G       G     What should we do here? What should happen if the child is grabbed? Move Parent or
                move child relative to parent ?
2 G       N     We check if parent is grabbable and if it is we move the parent?
3 N       G     Do we move the child relative to the parent or do we apply the transform to the parent?
4 N       N     Nothing

Do we find a solution that is always correct, or should we have options to specify behaviour for cases 1 and 2 ?

added 1 commit

• abffb24d - fix(interaction): use first encountered UInteractable

Compare with previous version

added 8 commits

• abffb24d...49b2e936 - 6 commits from branch vr-vis/VR-Group/unreal-development/plugins:dev/5.3
• 38c5fba2 - Merge branch 'refactor/pawn_movement_var' into '5.3'
• 6027ba91 - Merge branch rwth-vr-toolkit:5.3 into dev/5.3

Compare with previous version