/**
* Creates a static lighting vertex to represent the given static mesh vertex.
* @param VertexBuffer - The static mesh's vertex buffer.
* @param VertexIndex - The index of the static mesh vertex to access.
* @param OutVertex - Upon return, contains a static lighting vertex representing the specified static mesh vertex.
*/
static void GetStaticLightingVertex(
const FPositionVertexBuffer& PositionVertexBuffer,
const FStaticMeshVertexBuffer& VertexBuffer,
uint32 VertexIndex,
const FMatrix& LocalToWorld,
const FMatrix& LocalToWorldInverseTranspose,
FStaticLightingVertex& OutVertex
)
{
OutVertex.WorldPosition = LocalToWorld.TransformPosition(PositionVertexBuffer.VertexPosition(VertexIndex));
OutVertex.WorldTangentX = LocalToWorld.TransformVector(VertexBuffer.VertexTangentX(VertexIndex)).GetSafeNormal();
OutVertex.WorldTangentY = LocalToWorld.TransformVector(VertexBuffer.VertexTangentY(VertexIndex)).GetSafeNormal();
OutVertex.WorldTangentZ = LocalToWorldInverseTranspose.TransformVector(VertexBuffer.VertexTangentZ(VertexIndex)).GetSafeNormal();
checkSlow(VertexBuffer.GetNumTexCoords() <= ARRAY_COUNT(OutVertex.TextureCoordinates));
for(uint32 LightmapTextureCoordinateIndex = 0;LightmapTextureCoordinateIndex < VertexBuffer.GetNumTexCoords();LightmapTextureCoordinateIndex++)
{
OutVertex.TextureCoordinates[LightmapTextureCoordinateIndex] = VertexBuffer.GetVertexUV(VertexIndex,LightmapTextureCoordinateIndex);
}
}
void RemapPaintedVertexColors(
const TArray<FPaintedVertex>& InPaintedVertices,
const FColorVertexBuffer& InOverrideColors,
const FPositionVertexBuffer& NewPositions,
const FStaticMeshVertexBuffer* OptionalVertexBuffer,
TArray<FColor>& OutOverrideColors
)
{
// Local copy of painted vertices we can scratch on.
TArray<FPaintedVertex> PaintedVertices(InPaintedVertices);
// Find the extents formed by the cached vertex positions in order to optimize the octree used later
FVector MinExtents( PaintedVertices[ 0 ].Position );
FVector MaxExtents( PaintedVertices[ 0 ].Position );
for (int32 VertIndex = 0; VertIndex < PaintedVertices.Num(); ++VertIndex)
{
FVector& CurVector = PaintedVertices[ VertIndex ].Position;
MinExtents.X = FMath::Min<float>( MinExtents.X, CurVector.X );
MinExtents.Y = FMath::Min<float>( MinExtents.Y, CurVector.Y );
MinExtents.Z = FMath::Min<float>( MinExtents.Z, CurVector.Z );
MaxExtents.X = FMath::Max<float>( MaxExtents.X, CurVector.X );
MaxExtents.Y = FMath::Max<float>( MaxExtents.Y, CurVector.Y );
MaxExtents.Z = FMath::Max<float>( MaxExtents.Z, CurVector.Z );
}
// Create an octree which spans the extreme extents of the old and new vertex positions in order to quickly query for the colors
// of the new vertex positions
for (int32 VertIndex = 0; VertIndex < (int32)NewPositions.GetNumVertices(); ++VertIndex)
{
FVector CurVector = NewPositions.VertexPosition(VertIndex);
MinExtents.X = FMath::Min<float>( MinExtents.X, CurVector.X );
MinExtents.Y = FMath::Min<float>( MinExtents.Y, CurVector.Y );
MinExtents.Z = FMath::Min<float>( MinExtents.Z, CurVector.Z );
MaxExtents.X = FMath::Max<float>( MaxExtents.X, CurVector.X );
MaxExtents.Y = FMath::Max<float>( MaxExtents.Y, CurVector.Y );
MaxExtents.Z = FMath::Max<float>( MaxExtents.Z, CurVector.Z );
}
FBox Bounds( MinExtents, MaxExtents );
TSMCVertPosOctree VertPosOctree( Bounds.GetCenter(), Bounds.GetExtent().GetMax() );
// Add each old vertex to the octree
for ( int32 PaintedVertexIndex = 0; PaintedVertexIndex < PaintedVertices.Num(); ++PaintedVertexIndex )
{
VertPosOctree.AddElement( PaintedVertices[ PaintedVertexIndex ] );
}
// Iterate over each new vertex position, attempting to find the old vertex it is closest to, applying
// the color of the old vertex to the new position if possible.
OutOverrideColors.Empty(NewPositions.GetNumVertices());
const float DistanceOverNormalThreshold = OptionalVertexBuffer ? KINDA_SMALL_NUMBER : 0.0f;
for ( uint32 NewVertIndex = 0; NewVertIndex < NewPositions.GetNumVertices(); ++NewVertIndex )
{
TArray<FPaintedVertex> PointsToConsider;
TSMCVertPosOctree::TConstIterator<> OctreeIter( VertPosOctree );
const FVector& CurPosition = NewPositions.VertexPosition( NewVertIndex );
FVector CurNormal = FVector::ZeroVector;
if (OptionalVertexBuffer)
{
CurNormal = OptionalVertexBuffer->VertexTangentZ( NewVertIndex );
}
// Iterate through the octree attempting to find the vertices closest to the current new point
while ( OctreeIter.HasPendingNodes() )
{
const TSMCVertPosOctree::FNode& CurNode = OctreeIter.GetCurrentNode();
const FOctreeNodeContext& CurContext = OctreeIter.GetCurrentContext();
// Find the child of the current node, if any, that contains the current new point
FOctreeChildNodeRef ChildRef = CurContext.GetContainingChild( FBoxCenterAndExtent( CurPosition, FVector::ZeroVector ) );
if ( !ChildRef.IsNULL() )
{
const TSMCVertPosOctree::FNode* ChildNode = CurNode.GetChild( ChildRef );
// If the specified child node exists and contains any of the old vertices, push it to the iterator for future consideration
if ( ChildNode && ChildNode->GetInclusiveElementCount() > 0 )
{
OctreeIter.PushChild( ChildRef );
}
// If the child node doesn't have any of the old vertices in it, it's not worth pursuing any further. In an attempt to find
// anything to match vs. the new point, add all of the children of the current octree node that have old points in them to the
// iterator for future consideration.
else
{
FOREACH_OCTREE_CHILD_NODE( ChildRef )
{
if( CurNode.HasChild( ChildRef ) && CurNode.GetChild( ChildRef )->GetInclusiveElementCount() > 0 )
{
OctreeIter.PushChild( ChildRef );
}
}
}
}
// Add all of the elements in the current node to the list of points to consider for closest point calculations
PointsToConsider.Append( CurNode.GetElements() );
OctreeIter.Advance();
}
// If any points to consider were found, iterate over each and find which one is the closest to the new point
if ( PointsToConsider.Num() > 0 )
{
FPaintedVertex BestVertex = PointsToConsider[0];
float BestDistanceSquared = ( BestVertex.Position - CurPosition ).SizeSquared();
float BestNormalDot = FVector( BestVertex.Normal ) | CurNormal;
for ( int32 ConsiderationIndex = 1; ConsiderationIndex < PointsToConsider.Num(); ++ConsiderationIndex )
{
FPaintedVertex& Vertex = PointsToConsider[ ConsiderationIndex ];
const float DistSqrd = ( Vertex.Position - CurPosition ).SizeSquared();
const float NormalDot = FVector( Vertex.Normal ) | CurNormal;
if ( DistSqrd < BestDistanceSquared - DistanceOverNormalThreshold )
{
BestVertex = Vertex;
BestDistanceSquared = DistSqrd;
BestNormalDot = NormalDot;
}
else if ( OptionalVertexBuffer && DistSqrd < BestDistanceSquared + DistanceOverNormalThreshold && NormalDot > BestNormalDot )
{
BestVertex = Vertex;
BestDistanceSquared = DistSqrd;
BestNormalDot = NormalDot;
}
}
OutOverrideColors.Add(BestVertex.Color);
}
}
}