Entity.FindSweepHits Doesn't Hit Landscape

[Mudgecraft]

Summary

No Hits on Landscape when using the Entity.FindSweepHits() to find what is below my Prefab Entity

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Verse

Steps to Reproduce

Create a Prefab with a single Entity. Add a mesh_component, transform_component and the following verse component.

using { /Verse.org/Simulation }
using { /Verse.org/SceneGraph }
using { /Verse.org/SpatialMath }
using { /Verse.org/Colors }
using { /UnrealEngine.com/Temporary/Diagnostics }

sweep_test_component := class<final_super>(component):

    DownwardSweepDistance:float = 10000.0 # 100m
    DebugDraw:debug_draw = debug_draw{}
    
    OnBeginSimulation<override>():void =
        # Call parent implementation first
        (super:)OnBeginSimulation()
        
        spawn:
            RunLogic()

    RunLogic()<suspends>:void =
        loop:
            CurrentDistanceFromGround()
            Sleep(0.2)

    CurrentDistanceFromGround():float = 

        StartTransform := Entity.GetGlobalTransform()
        Displacement := vector3{Up := -1.0} * DownwardSweepDistance
        Extent := vector3{Up := 10.0, Left := 60.0, Forward := 90.0}
        Offset:float = 15.0
        CollisionVolume := collision_box{Extents := Extent, Collidable := true, Queryable := true}
        OffsetStartTransform := transform{
            Translation := StartTransform.Translation + vector3{Up := -Offset},
            Rotation := StartTransform.Rotation,
            Scale := StartTransform.Scale
        }
        
        # Debug
        StartPoint := StartTransform.Translation
        EndPoint := StartPoint + Displacement
        DebugDraw.DrawBox(Center := OffsetStartTransform.Translation, Rotation := OffsetStartTransform.Rotation, ?Extent := Extent, ?Color := NamedColors.LightGray, ?Duration := 0.2)
        
        # If we find any Hits, how far away are they?
        var ClosestDistance:float = DownwardSweepDistance
        var FoundAny : logic = false
        for (Hit : Entity.FindSweepHits(Displacement, OffsetStartTransform, CollisionVolume)):
            if (Hit.TargetComponent.Entity <> Entity):
                DebugDraw.DrawSphere(Hit.ContactPosition, ?Radius := 10.0, ?Color := NamedColors.Yellow, ?Duration := 0.2)
                CalculatedDistance:float = StartTransform.Translation.Up - Hit.ContactPosition.Up
                if (CalculatedDistance > 0.0 and CalculatedDistance < ClosestDistance):
                    set ClosestDistance = CalculatedDistance
                    set FoundAny = true
            else:
                DebugDraw.DrawSphere(Hit.ContactPosition, ?Radius := 10.0, ?Color := NamedColors.Green, ?Duration := 0.2)
                
        if (FoundAny?):
            DebugDraw.DrawLine(StartPoint, EndPoint, ?Color := NamedColors.Blue, ?Duration := 0.2, ?Thickness := 10.0)
            return ClosestDistance
        else:
            DebugDraw.DrawLine(StartPoint, EndPoint, ?Color := NamedColors.Red, ?Duration := 0.2, ?Thickness := 10.0)
            Print(Message := "Ground NOT found!", ?Duration := 5.0, ?Color := NamedColors.Red)
            return -1.0

Add some basic Landscape to the map. Drag and drop a number of the Entity into the world and run.

The verse script will draw a blue line if it encounters a sweep hit below itself within 100m. It will draw a yellow sphere at the point of the hit. Otherwise, it will draw a red line. A white box is drawn to represent the collision volume. And a green sphere is used to represent the start point of the sweep.

Expected Result

The line should be blue when over landscape with a yellow sphere at the ground level.

Observed Result

The sweep passes through the landscape without recording a hit.

Platform(s)

Windows

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Additional Notes

I’ve tried a number of variations on the verse i.e. with and without a collision volume, with and without an offset. The result always the same.