void UPaperTerrainComponent::InsertConvexCollisionDataFromPolygon(const TArray<FVector2D>& ClosedPolyVertices2D)
{
if (CachedBodySetup != nullptr && ClosedPolyVertices2D.Num() >= 3)
{
// Simplify polygon
TArray<float> EmptyOffsetsList;
TArray<FVector2D> LocalPolyVertices = ClosedPolyVertices2D;
SimplifyPolygon(LocalPolyVertices, EmptyOffsetsList);
// Always CCW and facing forward regardless of spline winding
TArray<FVector2D> CorrectedSplineVertices;
PaperGeomTools::CorrectPolygonWinding(CorrectedSplineVertices, LocalPolyVertices, false);
TArray<FVector2D> TriangulatedPolygonVertices;
PaperGeomTools::TriangulatePoly(/*out*/TriangulatedPolygonVertices, CorrectedSplineVertices, false);
TArray<TArray<FVector2D>> ConvexHulls;
PaperGeomTools::GenerateConvexPolygonsFromTriangles(ConvexHulls, TriangulatedPolygonVertices);
for (TArray<FVector2D> ConvexHull : ConvexHulls)
{
FKConvexElem Convex;
for (int J = 0; J < ConvexHull.Num(); ++J)
{
FVector2D& Vert = ConvexHull[J];
new(Convex.VertexData) FVector(Vert.X, -0.5f * CollisionThickness, Vert.Y);
new(Convex.VertexData) FVector(Vert.X, 0.5f * CollisionThickness, Vert.Y);
}
Convex.UpdateElemBox();
CachedBodySetup->AggGeom.ConvexElems.Add(Convex);
}
}
}
void UPaperTerrainComponent::GenerateCollisionDataFromPolygon(const TArray<FVector2D>& SplinePolyVertices2D, const TArray<float>& TerrainOffsets, const TArray<FVector2D>& TriangulatedPolygonVertices)
{
if (CachedBodySetup != nullptr && TriangulatedPolygonVertices.Num() >= 3)
{
// Generate polygon collider
TArray<TArray<FVector2D>> ConvexHulls;
PaperGeomTools::GenerateConvexPolygonsFromTriangles(ConvexHulls, TriangulatedPolygonVertices);
TArray<float> ConvexHullEdgeExtrusionAmount;
for (TArray<FVector2D> ConvexHull : ConvexHulls)
{
ConvexHullEdgeExtrusionAmount.Empty(ConvexHull.Num());
// Find distances for each edge in this convex hull from the pair of points forming the edge
// Not all edges will match edges in the original concave geometry, eg. newly created internal edges
//TODO: Speed this up by using indices / vertex & edge identifiers instead of brute force search
for (int ConvexHullPoint = 0; ConvexHullPoint < ConvexHull.Num(); ++ConvexHullPoint)
{
const FVector2D& A = ConvexHull[ConvexHullPoint];
const FVector2D& B = ConvexHull[(ConvexHullPoint + 1) % ConvexHull.Num()];
bool bFound = false;
for (int Vertex = 0; Vertex < SplinePolyVertices2D.Num(); ++Vertex)
{
// The winding is might be different to the source polygon, compare both ways
int NextVertexIndex = (Vertex + 1) % SplinePolyVertices2D.Num();
if ((A.Equals(SplinePolyVertices2D[Vertex], THRESH_POINTS_ARE_SAME) && B.Equals(SplinePolyVertices2D[NextVertexIndex], THRESH_POINTS_ARE_SAME)) ||
(B.Equals(SplinePolyVertices2D[Vertex], THRESH_POINTS_ARE_SAME) && A.Equals(SplinePolyVertices2D[NextVertexIndex], THRESH_POINTS_ARE_SAME)))
{
// Found an edge that matches the 2 vertex points
ConvexHullEdgeExtrusionAmount.Add(TerrainOffsets[Vertex]);
bFound = true;
break;
}
}
if (!bFound)
{
// Couldn't find this edge in the original polygon
ConvexHullEdgeExtrusionAmount.Add(0);
}
}
TArray<FVector2D> ExtrudedConvexHull;
CreateExtrudedConvexHull(ExtrudedConvexHull, ConvexHull, ConvexHullEdgeExtrusionAmount);
// ExtrudedConvexHull = ConvexHull;
// Generate convex hull
FKConvexElem Convex;
for (int J = 0; J < ExtrudedConvexHull.Num(); ++J)
{
FVector2D& Vert = ExtrudedConvexHull[J];
new(Convex.VertexData) FVector(Vert.X, -0.5f * CollisionThickness, Vert.Y);
new(Convex.VertexData) FVector(Vert.X, 0.5f * CollisionThickness, Vert.Y);
}
Convex.UpdateElemBox();
CachedBodySetup->AggGeom.ConvexElems.Add(Convex);
}
}
}
void UBodySetup::RescaleSimpleCollision( FVector BuildScale )
{
if( BuildScale3D != BuildScale )
{
// Back out the old scale when applying the new scale
const FVector ScaleMultiplier3D = (BuildScale / BuildScale3D);
for (int32 i = 0; i < AggGeom.ConvexElems.Num(); i++)
{
FKConvexElem* ConvexElem = &(AggGeom.ConvexElems[i]);
FTransform ConvexTrans = ConvexElem->GetTransform();
FVector ConvexLoc = ConvexTrans.GetLocation();
ConvexLoc *= ScaleMultiplier3D;
ConvexTrans.SetLocation(ConvexLoc);
ConvexElem->SetTransform(ConvexTrans);
TArray<FVector>& Vertices = ConvexElem->VertexData;
for (int32 VertIndex = 0; VertIndex < Vertices.Num(); ++VertIndex)
{
Vertices[VertIndex] *= ScaleMultiplier3D;
}
ConvexElem->UpdateElemBox();
}
// @todo Deal with non-vector properties by just applying the max value for the time being
const float ScaleMultiplier = ScaleMultiplier3D.GetMax();
for (int32 i = 0; i < AggGeom.SphereElems.Num(); i++)
{
FKSphereElem* SphereElem = &(AggGeom.SphereElems[i]);
SphereElem->Center *= ScaleMultiplier3D;
SphereElem->Radius *= ScaleMultiplier;
}
for (int32 i = 0; i < AggGeom.BoxElems.Num(); i++)
{
FKBoxElem* BoxElem = &(AggGeom.BoxElems[i]);
BoxElem->Center *= ScaleMultiplier3D;
BoxElem->X *= ScaleMultiplier3D.X;
BoxElem->Y *= ScaleMultiplier3D.Y;
BoxElem->Z *= ScaleMultiplier3D.Z;
}
for (int32 i = 0; i < AggGeom.SphylElems.Num(); i++)
{
FKSphylElem* SphylElem = &(AggGeom.SphylElems[i]);
SphylElem->Center *= ScaleMultiplier3D;
SphylElem->Radius *= ScaleMultiplier;
SphylElem->Length *= ScaleMultiplier;
}
BuildScale3D = BuildScale;
}
}
/** Utility for adding one convex hull from the given verts */
void AddConvexGeomFromVertices( const TArray<FVector>& Verts, FKAggregateGeom* AggGeom, const TCHAR* ObjName )
{
if(Verts.Num() == 0)
{
return;
}
FKConvexElem* ConvexElem = new(AggGeom->ConvexElems) FKConvexElem();
ConvexElem->VertexData = Verts;
ConvexElem->UpdateElemBox();
}
void UPaperTerrainComponent::InsertConvexCollisionDataFromPolygon(const TArray<FVector2D>& ClosedPolyVertices2D)
{
if (CachedBodySetup != nullptr && ClosedPolyVertices2D.Num() >= 3)
{
// Simplify polygon
TArray<float> EmptyOffsetsList;
TArray<FVector2D> LocalPolyVertices = ClosedPolyVertices2D;
// The merge / weld threshold should not be any lower / less than half the thickness
float PolygonThickness = (ClosedPolyVertices2D[0] - ClosedPolyVertices2D[ClosedPolyVertices2D.Num() - 1]).Size();
float SimplifyThreshold = PolygonThickness * 0.5f;
SimplifyPolygon(LocalPolyVertices, EmptyOffsetsList, SimplifyThreshold);
// Always CCW and facing forward regardless of spline winding
TArray<FVector2D> CorrectedSplineVertices;
PaperGeomTools::CorrectPolygonWinding(CorrectedSplineVertices, LocalPolyVertices, false);
TArray<FVector2D> TriangulatedPolygonVertices;
if (!PaperGeomTools::TriangulatePoly(/*out*/TriangulatedPolygonVertices, CorrectedSplineVertices, false))
{
// Triangulation failed, try triangulating the original non simplified polygon
CorrectedSplineVertices.Empty();
PaperGeomTools::CorrectPolygonWinding(/*out*/CorrectedSplineVertices, ClosedPolyVertices2D, false);
TriangulatedPolygonVertices.Empty();
PaperGeomTools::TriangulatePoly(/*out*/TriangulatedPolygonVertices, CorrectedSplineVertices, false);
}
TArray<TArray<FVector2D>> ConvexHulls;
PaperGeomTools::GenerateConvexPolygonsFromTriangles(ConvexHulls, TriangulatedPolygonVertices);
for (TArray<FVector2D> ConvexHull : ConvexHulls)
{
FKConvexElem Convex;
for (int J = 0; J < ConvexHull.Num(); ++J)
{
FVector2D& Vert = ConvexHull[J];
new(Convex.VertexData) FVector(Vert.X, -0.5f * CollisionThickness, Vert.Y);
new(Convex.VertexData) FVector(Vert.X, 0.5f * CollisionThickness, Vert.Y);
}
Convex.UpdateElemBox();
CachedBodySetup->AggGeom.ConvexElems.Add(Convex);
}
}
}
