Work-around for tiny radii sweeps #5474

src/ifcgeom/kernels/opencascade/OpenCascadeKernel.h

@@ -128,7 +128,7 @@ public:
 		const IfcGeom::ConversionResults& entity_shapes, const ifcopenshell::geometry::taxonomy::matrix4& entity_trsf, IfcGeom::ConversionResults& cut_shapes);
 	virtual bool unify_shapes(const IfcGeom::ConversionResults& input, IfcGeom::ConversionResults& output);
 
-	typedef boost::variant<Handle(Geom_Curve), TopoDS_Wire> curve_creation_visitor_result_type;
+	typedef boost::variant<boost::blank, Handle(Geom_Curve), TopoDS_Wire> curve_creation_visitor_result_type;
 	curve_creation_visitor_result_type convert_curve(const ifcopenshell::geometry::taxonomy::ptr);
 	Handle(Geom_Surface) convert_surface(const ifcopenshell::geometry::taxonomy::ptr);
 

src/ifcgeom/kernels/opencascade/face.cpp

@@ -151,7 +151,7 @@ namespace {
 			// It's a bit more convenient to use high level BRepPrimAPI calls that operate on
 			// topology. On a single edge that will create a Geom_TrimmedCurve for us.
 			auto crv_or_wire = kernel->convert_curve(i);
-			if (crv_or_wire.which() == 1) {
+			if (crv_or_wire.which() == 2) {
 				const auto& w = boost::get<TopoDS_Wire>(crv_or_wire);
 				return w;
 			} else {
@@ -163,8 +163,10 @@ namespace {
 			// @todo unify with trimmed curve handling
 			auto crv_or_wire = kernel->convert_curve(i);
 			if (crv_or_wire.which() == 0) {
+				throw std::runtime_error("Failed to obtain curve");
+			} else if (crv_or_wire.which() == 1) {
 				return boost::get<Handle(Geom_Curve)>(crv_or_wire);
-			} else {
+			} else if (crv_or_wire.which() == 2) {
 				// @todo
 				const double precision_ = 1.e-5;
 				Logger::Warning("Approximating BasisCurve due to possible discontinuities", i->instance);

src/ifcgeom/kernels/opencascade/loop.cpp

@@ -18,6 +18,7 @@
 #include <BRep_Tool.hxx>
 #include <TopTools_ListOfShape.hxx>
 #include <BRepTools_WireExplorer.hxx>
+#include <BRepBuilderAPI_Transform.hxx>
 
 #include <Standard_Version.hxx>
 #if OCC_VERSION_HEX < 0x70600
@@ -98,7 +99,7 @@ namespace {
 			if (!kernel->convert(l, wire)) {
 				throw std::runtime_error("Failed to convert loop to wire");
 			}
-			return result;
+			return result = wire;
 		}
 
 		OpenCascadeKernel::curve_creation_visitor_result_type operator()(const taxonomy::edge::ptr& e) {
@@ -119,6 +120,9 @@ namespace {
 				auto crv_or_wire = kernel->convert_curve(e_basis);
 				Handle(Geom_Curve) curve;
 				if (crv_or_wire.which() == 0) {
+					// raise exception
+					return result;
+				} else if (crv_or_wire.which() == 1) {
 					curve = boost::get<Handle(Geom_Curve)>(crv_or_wire);
 				} else {
 					// @todo
@@ -355,6 +359,17 @@ bool OpenCascadeKernel::convert(const taxonomy::loop::ptr loop, TopoDS_Wire& wir
 		wire = mw.Wire();
 	}
 
+	if (loop->matrix && !loop->matrix->is_identity()) {
+		const auto& m = loop->matrix->ccomponents();
+		gp_Trsf tr;
+		tr.SetValues(
+			m(0, 0), m(0, 1), m(0, 2), m(0, 3),
+			m(1, 0), m(1, 1), m(1, 2), m(1, 3),
+			m(2, 0), m(2, 1), m(2, 2), m(2, 3)
+		);
+		wire = TopoDS::Wire(BRepBuilderAPI_Transform(wire, tr).Shape());
+	}
+
 	return true;
 }
 

src/ifcgeom/kernels/opencascade/sweep_along_curve.cpp

@@ -34,8 +34,9 @@ using namespace IfcGeom::util;
 
 bool OpenCascadeKernel::convert(const taxonomy::sweep_along_curve::ptr scs, TopoDS_Shape& result) {
 	auto w = convert_curve(scs->curve);
-	if (w.which() == 0) {
+	if (w.which() != 2) {
 		Logger::Error("Unsupported directrix");
+		return false;
 	}
 	TopoDS_Shape face;
 	convert(taxonomy::cast<taxonomy::face>(scs->basis), face);
@@ -136,6 +137,9 @@ bool OpenCascadeKernel::convert(const taxonomy::sweep_along_curve::ptr scs, Topo
 		builder.SetMode(surface_face);
 	}
 	builder.Build();
+	if (!builder.IsDone()) {
+		return false;
+	}
 	builder.MakeSolid();
 	result = builder.Shape();
 
@@ -144,12 +148,45 @@ bool OpenCascadeKernel::convert(const taxonomy::sweep_along_curve::ptr scs, Topo
 
 bool OpenCascadeKernel::convert_impl(const taxonomy::sweep_along_curve::ptr scs, IfcGeom::ConversionResults& results) {
 	TopoDS_Shape shape;
+	// For tiny radii occt will fail building the sweep, in which case we enlarge the inputs to occt, and add a scale matrix to the output
+	bool enlarged = false;
+	static double enlarge_factor = 1000.;
+	if (scs->basis->kind() == taxonomy::FACE) {
+		auto w = std::static_pointer_cast<taxonomy::face>(scs->basis)->children[0];
+		if (w->children.size() == 1 && w->children[0]->basis && w->children[0]->basis->kind() == taxonomy::CIRCLE) {
+			auto circ = std::static_pointer_cast<taxonomy::circle>(w->children[0]->basis);
+			enlarged = circ->radius < 1.e-4;
+			if (enlarged) {
+				// @todo immutability
+				circ->radius *= enlarge_factor;
+				auto crv = std::static_pointer_cast<taxonomy::geom_item>(scs->curve);
+				if (crv->matrix) {
+					crv->matrix = taxonomy::make<taxonomy::matrix4>(
+						Eigen::Scaling(enlarge_factor) *
+						crv->matrix->ccomponents()
+					);
+				} else {
+					crv->matrix = taxonomy::make<taxonomy::matrix4>();
+					crv->matrix->components().topLeftCorner<3, 3>() = Eigen::Scaling(enlarge_factor, enlarge_factor, enlarge_factor).toDenseMatrix();
+				}
+			}
+		}
+	}
 	if (!convert(scs, shape)) {
 		return false;
 	}
+	taxonomy::matrix4::ptr m;
+	if (enlarged) {
+		m = taxonomy::make<taxonomy::matrix4>(
+			Eigen::Scaling(1. / enlarge_factor) *
+			scs->matrix->ccomponents()
+		);
+	} else {
+		m = scs->matrix;
+	}
 	results.emplace_back(ConversionResult(
 		scs->instance->as<IfcUtil::IfcBaseEntity>()->id(),
-		scs->matrix,
+		m,
 		new OpenCascadeShape(shape),
 		scs->surface_style
 	));