Gui: add method to select objects with a 3D ray (FreeCAD#16789)

* Implementation of ray picking method for 3d picking

* Ray picking logic moved to C++

(cherry picked from commit ed23214)

* formatting, do not return unecessary dict keys, near plane clipping

Author: kwahoo2

src/Gui/View3DInventor.cpp

@@ -47,9 +47,11 @@
 # include <Inventor/nodes/SoOrthographicCamera.h>
 # include <Inventor/nodes/SoPerspectiveCamera.h>
 # include <Inventor/nodes/SoSeparator.h>
+# include <Inventor/SoPickedPoint.h>
 #endif
 
 #include <App/Document.h>
+#include <App/GeoFeature.h>
 #include <Base/Builder3D.h>
 #include <Base/Console.h>
 #include <Base/Interpreter.h>
@@ -70,8 +72,10 @@
 #include "View3DInventorViewer.h"
 #include "View3DPy.h"
 #include "ViewProvider.h"
+#include "ViewProviderDocumentObject.h"
 #include "WaitCursor.h"
 
+#include "Utilities.h"
 
 using namespace Gui;
 
@@ -773,6 +777,97 @@ void View3DInventor::setCurrentViewMode(ViewMode newmode)
     }
 }
 
+RayPickInfo View3DInventor::getObjInfoRay(Base::Vector3d* startvec, Base::Vector3d* dirvec)
+{
+    double vsx, vsy, vsz;
+    double vdx, vdy, vdz;
+    vsx = startvec->x;
+    vsy = startvec->y;
+    vsz = startvec->z;
+    vdx = dirvec->x;
+    vdy = dirvec->y;
+    vdz = dirvec->z;
+    // near plane clipping is required to avoid false intersections
+    float near = 0.1;
+
+    RayPickInfo ret = {.isValid = false,
+                       .point = Base::Vector3d(),
+                       .document = "",
+                       .object = "",
+                       .parentObject = std::nullopt,
+                       .component = std::nullopt,
+                       .subName = std::nullopt};
+    SoRayPickAction action(getViewer()->getSoRenderManager()->getViewportRegion());
+    action.setRay(SbVec3f(vsx, vsy, vsz), SbVec3f(vdx, vdy, vdz), near);
+    action.apply(getViewer()->getSoRenderManager()->getSceneGraph());
+    SoPickedPoint* Point = action.getPickedPoint();
+
+    if (!Point) {
+        return ret;
+    }
+
+    ret.point = Base::convertTo<Base::Vector3d>(Point->getPoint());
+    ViewProvider* vp = getViewer()->getViewProviderByPath(Point->getPath());
+    if (vp && vp->isDerivedFrom(ViewProviderDocumentObject::getClassTypeId())) {
+        if (!vp->isSelectable()) {
+            return ret;
+        }
+        auto vpd = static_cast<ViewProviderDocumentObject*>(vp);
+        if (vp->useNewSelectionModel()) {
+            std::string subname;
+            if (!vp->getElementPicked(Point, subname)) {
+                return ret;
+            }
+            auto obj = vpd->getObject();
+            if (!obj) {
+                return ret;
+            }
+            if (!subname.empty()) {
+                App::ElementNamePair elementName;
+                auto sobj = App::GeoFeature::resolveElement(obj, subname.c_str(), elementName);
+                if (!sobj) {
+                    return ret;
+                }
+                if (sobj != obj) {
+                    ret.parentObject = obj->getExportName();
+                    ret.subName = subname;
+                    obj = sobj;
+                }
+                subname = !elementName.oldName.empty() ? elementName.oldName : elementName.newName;
+            }
+            ret.document = obj->getDocument()->getName();
+            ret.object = obj->getNameInDocument();
+            ret.component = subname;
+            ret.isValid = true;
+        }
+        else {
+            ret.document = vpd->getObject()->getDocument()->getName();
+            ret.object = vpd->getObject()->getNameInDocument();
+            // search for a SoFCSelection node
+            SoFCDocumentObjectAction objaction;
+            objaction.apply(Point->getPath());
+            if (objaction.isHandled()) {
+                ret.component = objaction.componentName.getString();
+            }
+        }
+        // ok, found the node of interest
+        ret.isValid = true;
+    }
+    else {
+        // custom nodes not in a VP: search for a SoFCSelection node
+        SoFCDocumentObjectAction objaction;
+        objaction.apply(Point->getPath());
+        if (objaction.isHandled()) {
+            ret.document = objaction.documentName.getString();
+            ret.object = objaction.objectName.getString();
+            ret.component = objaction.componentName.getString();
+            // ok, found the node of interest
+            ret.isValid = true;
+        }
+    }
+    return ret;
+}
+
 bool View3DInventor::eventFilter(QObject* watched, QEvent* e)
 {
     // As long as this widget is a top-level window (either in 'TopLevel' or 'FullScreen' mode) we

src/Gui/View3DInventor.h

@@ -31,6 +31,7 @@
 
 #include "MDIView.h"
 
+#include "Base/Vector3D.h"
 
 class QPrinter;
 class QStackedWidget;
@@ -43,6 +44,16 @@ class View3DPy;
 class View3DSettings;
 class NaviCubeSettings;
 
+struct RayPickInfo
+{
+    bool isValid;
+    Base::Vector3d point;
+    std::string document;
+    std::string object;
+    std::optional<std::string> parentObject;
+    std::optional<std::string> component;
+    std::optional<std::string> subName;
+};
 class GuiExport GLOverlayWidget : public QWidget
 {
     Q_OBJECT
@@ -98,6 +109,8 @@ class GuiExport View3DInventor : public MDIView
      * GL widget to get all key events in \a TopLevel or \a Fullscreen mode.
      */
     void setCurrentViewMode(ViewMode b) override;
+    RayPickInfo getObjInfoRay(Base::Vector3d* startvec,
+                                 Base::Vector3d* dirvec);
     bool setCamera(const char* pCamera);
     void toggleClippingPlane();
     bool hasClippingPlane() const;

src/Gui/View3DPy.cpp

@@ -158,6 +158,14 @@ void View3DInventorPy::init_type()
         "\n"
         "Does the same as getObjectInfo() but returns a list of dictionaries or None.\n");
     add_noargs_method("getSize",&View3DInventorPy::getSize,"getSize()");
+    add_varargs_method("getObjectInfoRay",&View3DInventorPy::getObjectInfoRay,
+        "getObjectInfoRay(tuple(3D vector,3D vector) or tuple of 6 floats) -> dictionary or None\n"
+        "\n"
+        "Vectors represent start point and direction of intersection ray\n"
+        "Return a dictionary with the name of document, object and component. The\n"
+        "dictionary also contains the coordinates of the appropriate 3d point of\n"
+        "the underlying geometry in the scenegraph.\n"
+        "If no geometry was found 'None' is returned, instead.\n");
     add_varargs_method("getPoint",&View3DInventorPy::getPointOnFocalPlane,
         "Same as getPointOnFocalPlane");
     add_varargs_method("getPointOnFocalPlane",&View3DInventorPy::getPointOnFocalPlane,
@@ -1501,6 +1509,54 @@ Py::Object View3DInventorPy::getObjectsInfo(const Py::Tuple& args)
     }
 }
 
+Py::Object View3DInventorPy::getObjectInfoRay(const Py::Tuple& args)
+{
+    PyObject* vs;
+    PyObject* vd;
+    double vsx, vsy, vsz;
+    double vdx, vdy, vdz;
+    Py::Object ret = Py::None();
+    if (PyArg_ParseTuple(args.ptr(),
+                         "O!O!",
+                         &Base::VectorPy::Type,
+                         &vs,
+                         &Base::VectorPy::Type,
+                         &vd)) {
+        Base::Vector3d* startvec = static_cast<Base::VectorPy*>(vs)->getVectorPtr();
+        Base::Vector3d* dirvec = static_cast<Base::VectorPy*>(vd)->getVectorPtr();
+        try {
+            RayPickInfo pinfo = getView3DIventorPtr()->getObjInfoRay(startvec, dirvec);
+            if (!pinfo.isValid) {
+                return ret;
+            }
+            Py::Dict dict;
+            dict.setItem("PickedPoint", Py::asObject(new Base::VectorPy(pinfo.point)));
+            dict.setItem("Document", Py::String(pinfo.document));
+            dict.setItem("Object", Py::String(pinfo.object));
+            if (pinfo.parentObject) {
+                dict.setItem("ParentObject", Py::String(pinfo.parentObject.value()));
+            }
+            if (pinfo.component) {
+                dict.setItem("Component", Py::String(pinfo.component.value()));
+            }
+            if (pinfo.subName) {
+                dict.setItem("SubName", Py::String(pinfo.subName.value()));
+            }
+            ret = dict;
+        }
+        catch (const Py::Exception&) {
+            throw;
+        }
+    }
+    else {
+        PyErr_Clear();
+        if (!PyArg_ParseTuple(args.ptr(), "dddddd", &vsx, &vsy, &vsz, &vdx, &vdy, &vdz)) {
+            throw Py::TypeError("Wrong arguments, two Vectors or six floats expected");
+        }
+    }
+    return ret;
+}
+
 Py::Object View3DInventorPy::getSize()
 {
     try {

src/Gui/View3DPy.h

@@ -95,6 +95,7 @@ class View3DInventorPy : public Py::PythonExtension<View3DInventorPy>
     Py::Object getObjectInfo(const Py::Tuple&);
     Py::Object getObjectsInfo(const Py::Tuple&);
     Py::Object getSize();
+    Py::Object getObjectInfoRay(const Py::Tuple&);
     Py::Object getPointOnFocalPlane(const Py::Tuple&);
     Py::Object projectPointToLine(const Py::Tuple&);
     Py::Object getPointOnViewport(const Py::Tuple&);