Import: fixes #8666: Enable support to read glTF files

src/Mod/Import/App/AppImportPy.cpp

@@ -73,6 +73,7 @@
 #include <Mod/Part/App/encodeFilename.h>
 
 #include "ImportOCAF2.h"
+#include "ReaderGltf.h"
 #include "WriterGltf.h"
 
 namespace Import
@@ -248,6 +249,10 @@ private:
                     pcDoc->recompute();
                 }
             }
+            else if (file.hasExtension({"glb", "gltf"})) {
+                Import::ReaderGltf reader(file);
+                reader.read(hDoc);
+            }
             else {
                 throw Py::Exception(PyExc_IOError, "no supported file format");
             }

src/Mod/Import/App/ReaderGltf.cpp

@@ -24,9 +24,89 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
+#include <sstream>
 #include <Standard_Version.hxx>
+#include <TDF_Label.hxx>
+#include <TDF_TagSource.hxx>
+#include <XCAFDoc_DocumentTool.hxx>
+#include <XCAFDoc_ShapeTool.hxx>
+#if OCC_VERSION_HEX >= 0x070500
+#include <Message_ProgressRange.hxx>
+#include <RWGltf_CafReader.hxx>
+#endif
 #endif
 
 #include "ReaderGltf.h"
+#include <Base/Exception.h>
+#include <Mod/Part/App/TopoShape.h>
+#include <Mod/Part/App/Tools.h>
 
 using namespace Import;
+
+ReaderGltf::ReaderGltf(const Base::FileInfo& file)  // NOLINT
+    : file {file}
+{}
+
+void ReaderGltf::read(Handle(TDocStd_Document) hDoc)  // NOLINT
+{
+#if OCC_VERSION_HEX >= 0x070500
+    const double unit = 0.001;  // mm
+    RWGltf_CafReader aReader;
+    aReader.SetSystemLengthUnit(unit);
+    aReader.SetSystemCoordinateSystem(RWMesh_CoordinateSystem_Zup);
+    aReader.SetDocument(hDoc);
+    aReader.SetParallel(true);
+
+    TCollection_AsciiString filename(file.filePath().c_str());
+    Standard_Boolean ret = aReader.Perform(filename, Message_ProgressRange());
+    if (!ret) {
+        std::stringstream str;
+        str << "Cannot read from file '"
+            << "" << file.filePath() << "'";
+    }
+
+    Handle(XCAFDoc_ShapeTool) aShapeTool = XCAFDoc_DocumentTool::ShapeTool(hDoc->Main());
+    TDF_LabelSequence labels;
+    aShapeTool->GetShapes(labels);
+    for (Standard_Integer i = 1; i <= labels.Length(); i++) {
+        auto label = labels.Value(i);
+        TopoDS_Shape shape = aShapeTool->GetShape(label);
+        if (!shape.IsNull()) {
+            aShapeTool->SetShape(label, fixShape(shape));
+        }
+    }
+
+#else
+    throw Base::RuntimeError("gITF support requires OCCT 7.5.0 or later");
+#endif
+}
+
+bool ReaderGltf::cleanup() const
+{
+    return clean;
+}
+
+void ReaderGltf::setCleanup(bool value)
+{
+    clean = value;
+}
+
+TopoDS_Shape ReaderGltf::fixShape(TopoDS_Shape shape)  // NOLINT
+{
+    // The glTF reader creates a compound of faces that only contains the triangulation
+    // but not the underlying surfaces. This leads to faces without boundaries.
+    // The triangulation is used to create a valid shape.
+    const double tolerance = 0.5;
+    std::vector<Base::Vector3d> points;
+    std::vector<Data::ComplexGeoData::Facet> facets;
+    Part::TopoShape sh(shape);
+    sh.getFaces(points, facets, tolerance);
+    sh.setFaces(points, facets, tolerance);
+
+    if (cleanup()) {
+        sh.sewShape();
+        return sh.removeSplitter();
+    }
+
+    return sh.getShape();
+}

src/Mod/Import/App/ReaderGltf.h

@@ -24,9 +24,31 @@
 #ifndef IMPORT_READER_GLTF_H
 #define IMPORT_READER_GLTF_H
 
+#include <Mod/Import/ImportGlobal.h>
+#include <Base/FileInfo.h>
+#include <TDocStd_Document.hxx>
+#include <TopoDS_Shape.hxx>
+
 namespace Import
 {
 
-}
+class ImportExport ReaderGltf
+{
+public:
+    explicit ReaderGltf(const Base::FileInfo& file);
+
+    void read(Handle(TDocStd_Document) hDoc);
+    bool cleanup() const;
+    void setCleanup(bool);
+
+private:
+    TopoDS_Shape fixShape(TopoDS_Shape);
+
+private:
+    Base::FileInfo file;
+    bool clean = true;
+};
+
+}  // namespace Import
 
 #endif  // IMPORT_READER_GLTF_H

src/Mod/Import/Gui/AppImportGuiPy.cpp

@@ -104,6 +104,7 @@
 #include <Gui/MainWindow.h>
 #include <Gui/ViewProviderLink.h>
 #include <Mod/Import/App/ImportOCAF2.h>
+#include <Mod/Import/App/ReaderGltf.h>
 #include <Mod/Import/App/WriterGltf.h>
 #include <Mod/Part/App/ImportIges.h>
 #include <Mod/Part/App/ImportStep.h>
@@ -523,6 +524,10 @@ private:
                     pcDoc->recompute();
                 }
             }
+            else if (file.hasExtension({"glb", "gltf"})) {
+                Import::ReaderGltf reader(file);
+                reader.read(hDoc);
+            }
             else {
                 throw Py::Exception(PyExc_IOError, "no supported file format");
             }
@@ -537,7 +542,9 @@ private:
             if (useLinkGroup != Py_None) {
                 ocaf.setUseLinkGroup(Base::asBoolean(useLinkGroup));
             }
-            ocaf.setMode(mode);
+            if (mode >= 0) {
+                ocaf.setMode(mode);
+            }
             auto ret = ocaf.loadShapes();
             hApp->Close(hDoc);
             FC_DURATION_PLUS(d2, t);

src/Mod/Import/Init.py

@@ -31,5 +31,6 @@
 # FreeCAD.addExportType("IGES files (*.iges *.igs)","ImportGui")
 FreeCAD.addImportType("PLMXML files (*.plmxml)", "PlmXmlParser")
 FreeCAD.addImportType("STEPZ Zip File Type (*.stpZ *.stpz)", "stepZ")
+FreeCAD.addImportType("glTF (*.gltf *.glb)", "ImportGui")
 FreeCAD.addExportType("STEPZ zip File Type (*.stpZ *.stpz)", "stepZ")
 FreeCAD.addExportType("glTF (*.gltf *.glb)", "ImportGui")