// NB: ElemTM is assumed to have no scaling in it!
void FKConvexElem::DrawElemWire(FPrimitiveDrawInterface* PDI, const FTransform& ElemTM, const FVector& Scale3D, const FColor Color)
{
#if WITH_PHYSX
FTransform LocalToWorld = ElemTM;
LocalToWorld.SetScale3D(Scale3D);
PxConvexMesh* Mesh = ConvexMesh;
if(Mesh)
{
// Draw each triangle that makes up the convex hull
PxU32 NbVerts = Mesh->getNbVertices();
const PxVec3* Vertices = Mesh->getVertices();
TArray<FVector> TransformedVerts;
TransformedVerts.AddUninitialized(NbVerts);
for(PxU32 i=0; i<NbVerts; i++)
{
TransformedVerts[i] = LocalToWorld.TransformPosition( P2UVector(Vertices[i]) );
}
const PxU8* PIndexBuffer = Mesh->getIndexBuffer();
PxU32 NbPolygons = Mesh->getNbPolygons();
for(PxU32 i=0;i<NbPolygons;i++)
{
PxHullPolygon Data;
bool bStatus = Mesh->getPolygonData(i, Data);
check(bStatus);
const PxU8* PIndices = PIndexBuffer + Data.mIndexBase;
for(PxU16 j=0;j<Data.mNbVerts;j++)
{
// Get the verts that make up this line.
int32 I0 = PIndices[j];
int32 I1 = PIndices[j+1];
// Loop back last and first vertices
if(j==Data.mNbVerts - 1)
{
I1 = PIndices[0];
}
PDI->DrawLine( TransformedVerts[I0], TransformedVerts[I1], Color, SDPG_World );
}
}
}
else
{
UE_LOG(LogPhysics, Log, TEXT("FKConvexElem::DrawElemWire : No ConvexMesh, so unable to draw."));
}
#endif // WITH_PHYSX
}
Mesh* ConvexHull::newMesh(Array<Vector3> points, VertexDescriptor& descriptor,
GraphicsSystem& graphicsSystem, PhysicsSystem& physicsSystem) {
GraphicsAPI& graphicsAPI = graphicsSystem.getAPI();
PxConvexMesh* pxMesh = compute(points, physicsSystem);
FDUint vertexCount = pxMesh->getNbVertices();
FDUint byteSize = vertexCount * descriptor.getVertexSize();
FDUint polygonCount = pxMesh->getNbPolygons();
GeometryAuthor author(descriptor, graphicsAPI.getDynamicAllocator());
const PxU8* indices = pxMesh->getIndexBuffer();
for (FDUint i = 0; i < polygonCount; i++) {
PxHullPolygon polygon;
FDbool success = pxMesh->getPolygonData(i, polygon);
if (!success) {
FD_THROW(GenericException("Failed to get polygon data.\n"));
}
FDUint firstIndex = 0;
for (FDUint j = 0; j < polygon.mNbVerts; j++) {
PxU8 cIndex = *(indices + polygon.mIndexBase + j);
FDUint myIndex = author.newPoint(pxMesh->getVertices()[cIndex]);
if (j == 0) {
firstIndex = myIndex;
}
}
for (FDUint j = 2; j < polygon.mNbVerts; j++) {
FDUint i1 = firstIndex;
FDUint i2 = firstIndex + j - 1;
FDUint i3 = firstIndex + j;
author.newTriangle(i1, i2, i3);
}
}
author.postProcess();
Mesh* mesh = graphicsSystem.getAPI().newMesh(author);
return mesh;
}
