I want to make the grabber have less inertia when grabbing things. Right now if you grab an object, it very slowly adapts it’s location to your current camera position (has a lot of inertia while moving the camera around). I wanted to make it more like grabbing an object with the gravity gun in Half Life 2, so that it basically snaps to the final position and also does not get rotated around when moving. Is there a simple way I can change the code for that to work?
// Fill out your copyright notice in the Description page of Project Settings.
#include "Grabber.h"
#include "Engine/World.h"
#include "DrawDebugHelpers.h"
// Sets default values for this component's properties
UGrabber::UGrabber()
{
// Set this component to be initialized when the game starts, and to be ticked every frame. You can turn these features
// off to improve performance if you don't need them.
PrimaryComponentTick.bCanEverTick = true;
}
// Called when the game starts
void UGrabber::BeginPlay()
{
Super::BeginPlay();
}
// Called every frame
void UGrabber::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)
{
Super::TickComponent(DeltaTime, TickType, ThisTickFunction);
UPhysicsHandleComponent* PhysicsHandle = GetPhysicsHandle();
if (PhysicsHandle && PhysicsHandle->GetGrabbedComponent())
{
FVector TargetLocation = GetComponentLocation() + GetForwardVector()*HoldDistance;
PhysicsHandle->SetTargetLocationAndRotation(TargetLocation,GetComponentRotation());
}
}
void UGrabber::Release(){
UPhysicsHandleComponent* PhysicsHandle = GetPhysicsHandle();
if (PhysicsHandle && PhysicsHandle->GetGrabbedComponent())
{
AActor* GrabbedActor = PhysicsHandle->GetGrabbedComponent()->GetOwner();
GrabbedActor->Tags.Remove("Grabbed");
PhysicsHandle->ReleaseComponent();
}
}
void UGrabber::Grab()
{
UPhysicsHandleComponent* PhysicsHandle = GetPhysicsHandle();
if (PhysicsHandle == nullptr)
{
return;
}
FHitResult HitResult;
bool HasHit = GetGrabbableInReach(HitResult);
if (HasHit)
{
UPrimitiveComponent* HitComponent = HitResult.GetComponent();
HitComponent->SetSimulatePhysics(true);
HitComponent->WakeAllRigidBodies();
AActor* HitActor = HitResult.GetActor();
HitActor->Tags.Add("Grabbed");
HitActor->DetachFromActor(FDetachmentTransformRules::KeepWorldTransform);
PhysicsHandle->GrabComponentAtLocationWithRotation(
HitComponent,
NAME_None,
HitResult.ImpactPoint,
GetComponentRotation()
);
}
}
UPhysicsHandleComponent* UGrabber::GetPhysicsHandle() const
{
UPhysicsHandleComponent* PhysicsHandle = GetOwner()->FindComponentByClass<UPhysicsHandleComponent>();
if (PhysicsHandle == nullptr)
{
UE_LOG(LogTemp, Display, TEXT("Grabber requires a UPhysicsHandle Component"));
}
return PhysicsHandle;
}
bool UGrabber::GetGrabbableInReach(FHitResult& OutHitResult) const
{
FVector Start = GetComponentLocation();
FVector End = GetForwardVector()*MaxGrabDistance + Start;
DrawDebugLine(GetWorld(),Start,End,FColor::Red,false,5);
DrawDebugSphere(GetWorld(),End,50,10,FColor::Emerald,false,5);
FCollisionShape Sphere = FCollisionShape::MakeSphere(GrabRadius);
return GetWorld()->SweepSingleByChannel(
OutHitResult,
Start,
End,
FQuat::Identity,
ECC_GameTraceChannel2,
Sphere);
}
I tried to set GetComponentRotation() to a fixed FRotator(0,0,0) in the Grab() function, but that only leads to errors. Can anyone tell me how to do this?
