FEM: Constraint view sizing and scaling of indicators for force, pressure and fixed constraints and limit on steps.

src/Mod/Fem/App/FemConstraint.cpp

@@ -57,6 +57,7 @@
 #include <Mod/Part/App/PartFeature.h>
 #include <Base/Console.h>
 #include <Base/Exception.h>
+#include <math.h> //OvG: Required for log10
 
 using namespace Fem;
 
@@ -71,6 +72,7 @@ Constraint::Constraint()
 {
     ADD_PROPERTY_TYPE(References,(0,0),"Constraint",(App::PropertyType)(App::Prop_None),"Elements where the constraint is applied");
     ADD_PROPERTY_TYPE(NormalDirection,(Base::Vector3d(0,0,1)),"Constraint",App::PropertyType(App::Prop_ReadOnly|App::Prop_Output),"Normal direction pointing outside of solid");
+    ADD_PROPERTY_TYPE(Scale,(1),"Base",App::PropertyType(App::Prop_Output),"Scale used for drawing constraints"); //OvG: Add scale parameter inherited by all derived constraints
 }
 
 Constraint::~Constraint()
@@ -80,12 +82,29 @@ Constraint::~Constraint()
 App::DocumentObjectExecReturn *Constraint::execute(void)
 {
     References.touch();
+    Scale.touch();
     return StdReturn;
 }
 
+//OvG: Provide the ability to determine how big to draw constraint arrows etc.
+int Constraint::calcDrawScaleFactor(double lparam) const
+{
+    return ((int)round(log(lparam)*log(lparam)*log(lparam)/10)>1)?((int)round(log(lparam)*log(lparam)*log(lparam)/10)):1;
+}
+
+int Constraint::calcDrawScaleFactor(double lvparam, double luparam) const
+{
+    return calcDrawScaleFactor((lvparam+luparam)/2.0);
+}
+
+int Constraint::calcDrawScaleFactor() const
+{
+    return 1;
+}
+#define CONSTRAINTSTEPLIMIT 50
+
 void Constraint::onChanged(const App::Property* prop)
 {
-    //Base::Console().Error("Constraint::onChanged() %s\n", prop->getName());
     if (prop == &References) {
         // If References are changed, recalculate the normal direction. If no useful reference is found,
         // use z axis or previous value. If several faces are selected, only the first one is used
@@ -131,7 +150,7 @@ void Constraint::onDocumentRestored()
     App::DocumentObject::onDocumentRestored();
 }
 
-const bool Constraint::getPoints(std::vector<Base::Vector3d> &points, std::vector<Base::Vector3d> &normals) const
+const bool Constraint::getPoints(std::vector<Base::Vector3d> &points, std::vector<Base::Vector3d> &normals, int * scale) const
 {
     std::vector<App::DocumentObject*> Objects = References.getValues();
     std::vector<std::string> SubElements = References.getSubValues();
@@ -152,6 +171,11 @@ const bool Constraint::getPoints(std::vector<Base::Vector3d> &points, std::vecto
             gp_Pnt p = BRep_Tool::Pnt(vertex);
             points.push_back(Base::Vector3d(p.X(), p.Y(), p.Z()));
             normals.push_back(NormalDirection.getValue());
+            //OvG: Scale by whole object mass in case of a vertex
+            GProp_GProps props;
+			BRepGProp::VolumeProperties(toposhape._Shape, props);
+			double lx = props.Mass();
+            *scale = this->calcDrawScaleFactor(sqrt(lx)); //OvG: setup draw scale for constraint
         } else if (sh.ShapeType() == TopAbs_EDGE) {
             BRepAdaptor_Curve curve(TopoDS::Edge(sh));
             double fp = curve.FirstParameter();
@@ -161,10 +185,23 @@ const bool Constraint::getPoints(std::vector<Base::Vector3d> &points, std::vecto
             double l = props.Mass();
             // Create points with 10 units distance, but at least one at the beginning and end of the edge
             int steps;
-            if (l >= 20)
+            if (l >= 100) //OvG: Increase 10 units distance proportionately to l for larger objects.
+            {
+                *scale = this->calcDrawScaleFactor(l); //OvG: setup draw scale for constraint
+                steps = (int)round(l / (10*( *scale)));
+                steps = steps<3?3:steps;
+            }
+            else if (l >= 20)
+            {
                 steps = (int)round(l / 10);
+                *scale = this->calcDrawScaleFactor(); //OvG: setup draw scale for constraint
+            }
             else
+            {
                 steps = 1;
+                *scale = this->calcDrawScaleFactor(); //OvG: setup draw scale for constraint
+            }
+            steps = steps>CONSTRAINTSTEPLIMIT?CONSTRAINTSTEPLIMIT:steps; //OvG: Place upper limit on number of steps
             double step = (lp - fp) / steps;
             for (int i = 0; i < steps + 1; i++) {
                 gp_Pnt p = curve.Value(i * step);
@@ -195,15 +232,41 @@ const bool Constraint::getPoints(std::vector<Base::Vector3d> &points, std::vecto
             isoc.Load(GeomAbs_IsoV, ulp);
             double lu = (l + GCPnts_AbscissaPoint::Length(isoc, Precision::Confusion()))/2.0;
             int stepsv;
-            if (lv >= 20.0)
+            if (lv >= 100) //OvG: Increase 10 units distance proportionately to lv for larger objects.
+            {
+                *scale = this->calcDrawScaleFactor(lv,lu); //OvG: setup draw scale for constraint
+                stepsv = (int)round(lv / (10*( *scale)));
+                stepsv = stepsv<3?3:stepsv;
+            }
+            else if (lv >= 20.0)
+            {
                 stepsv = (int)round(lv / 10);
+                *scale = this->calcDrawScaleFactor(); //OvG: setup draw scale for constraint
+            }
             else
+            {
                 stepsv = 2; // Minimum of three arrows to ensure (as much as possible) that at least one is displayed
+                *scale = this->calcDrawScaleFactor(); //OvG: setup draw scale for constraint
+            }
+            stepsv = stepsv>CONSTRAINTSTEPLIMIT?CONSTRAINTSTEPLIMIT:stepsv; //OvG: Place upper limit on number of steps
             int stepsu;
-            if (lu >= 20.0)
+            if (lu >= 100) //OvG: Increase 10 units distance proportionately to lu for larger objects.
+            {
+                *scale = this->calcDrawScaleFactor(lv,lu); //OvG: setup draw scale for constraint
+                stepsu = (int)round(lu / (10*( *scale)));
+                stepsu = stepsu<3?3:stepsu;
+            }
+            else if (lu >= 20.0)
+            {
                 stepsu = (int)round(lu / 10);
+                *scale = this->calcDrawScaleFactor(); //OvG: setup draw scale for constraint
+            }
             else
+            {
                 stepsu = 2;
+                *scale = this->calcDrawScaleFactor(); //OvG: setup draw scale for constraint
+            }
+            stepsu = stepsu>CONSTRAINTSTEPLIMIT?CONSTRAINTSTEPLIMIT:stepsu; //OvG: Place upper limit on number of steps
             double stepv = (vlp - vfp) / stepsv;
             double stepu = (ulp - ufp) / stepsu;
             // Create points and normals

src/Mod/Fem/App/FemConstraint.h

@@ -44,6 +44,9 @@ public:
     App::PropertyLinkSubList References;
     // Read-only (calculated values). These trigger changes in the ViewProvider
     App::PropertyVector NormalDirection;
+    
+    //OvG: Scale
+    App::PropertyInteger Scale;
 
     /// recalculate the object
     virtual App::DocumentObjectExecReturn *execute(void);
@@ -52,6 +55,11 @@ public:
     virtual const char* getViewProviderName(void) const {
         return "FemGui::ViewProviderFemConstraint";
     }
+    
+    //OvG: Allow automatic determination of scaling of constraint drawings, e.g. arrow length and size
+    int calcDrawScaleFactor(double lparam) const;
+    int calcDrawScaleFactor(double lvparam, double luparam) const;
+    int calcDrawScaleFactor() const;
 
 protected:
     virtual void onChanged(const App::Property* prop);
@@ -59,7 +67,7 @@ protected:
 
 protected:
     /// Calculate the points where symbols should be drawn
-    const bool getPoints(std::vector<Base::Vector3d>& points, std::vector<Base::Vector3d>& normals) const;
+    const bool getPoints(std::vector<Base::Vector3d>& points, std::vector<Base::Vector3d>& normals, int * scale) const; //OvG: added scale parameter
     const bool getCylinder(double& radius, double& height, Base::Vector3d& base, Base::Vector3d& axis) const;
     Base::Vector3d getBasePoint(const Base::Vector3d& base, const Base::Vector3d& axis,
                                 const App::PropertyLinkSub &location, const double& dist);

src/Mod/Fem/App/FemConstraintFixed.cpp

@@ -75,9 +75,11 @@ void ConstraintFixed::onChanged(const App::Property* prop)
     if (prop == &References) {
         std::vector<Base::Vector3d> points;
         std::vector<Base::Vector3d> normals;
-        if (getPoints(points, normals)) {
+        int scale = 1; //OvG: Enforce use of scale
+        if (getPoints(points, normals, &scale)) {
             Points.setValues(points);
             Normals.setValues(normals);
+            Scale.setValue(scale); //OvG: Scale
             Points.touch(); // This triggers ViewProvider::updateData()
         }
     }

src/Mod/Fem/App/FemConstraintForce.cpp

@@ -70,8 +70,11 @@ void ConstraintForce::onChanged(const App::Property* prop)
     if (prop == &References) {
         std::vector<Base::Vector3d> points;
         std::vector<Base::Vector3d> normals;
-        if (getPoints(points, normals)) {
+        int scale = 1; //OvG: Enforce use of scale
+        if (getPoints(points, normals, &scale)) {
             Points.setValues(points); // We don't use the normals because all arrows should have the same direction
+            Scale.setValue(scale); //OvG Scale
+            Points.touch();
         }
     } else if (prop == &Direction) {
         Base::Vector3d direction = getDirection(Direction);

src/Mod/Fem/App/FemConstraintPressure.cpp

@@ -70,9 +70,11 @@ void ConstraintPressure::onChanged(const App::Property* prop)
     if (prop == &References) {
         std::vector<Base::Vector3d> points;
         std::vector<Base::Vector3d> normals;
-        if (getPoints(points, normals)) {
+        int scale = Scale.getValue();
+        if (getPoints(points, normals, &scale)) {
             Points.setValues(points);
             Normals.setValues(normals);
+            Scale.setValue(scale);
             Points.touch();
         }
     } else if (prop == &Reversed) {

src/Mod/Fem/Gui/Command.cpp

@@ -315,6 +315,7 @@ void CmdFemConstraintFixed::activated(int iMsg)
 
     openCommand("Make FEM constraint fixed geometry");
     doCommand(Doc,"App.activeDocument().addObject(\"Fem::ConstraintFixed\",\"%s\")",FeatName.c_str());
+    doCommand(Doc,"App.activeDocument().%s.Scale = 1",FeatName.c_str()); //OvG: set initial scale to 1
     doCommand(Doc,"App.activeDocument().%s.Member = App.activeDocument().%s.Member + [App.activeDocument().%s]",Analysis->getNameInDocument(),Analysis->getNameInDocument(),FeatName.c_str());
     updateActive();
 
@@ -353,7 +354,9 @@ void CmdFemConstraintForce::activated(int iMsg)
 
     openCommand("Make FEM constraint force on geometry");
     doCommand(Doc,"App.activeDocument().addObject(\"Fem::ConstraintForce\",\"%s\")",FeatName.c_str());
-    doCommand(Doc,"App.activeDocument().%s.Force = 0.0",FeatName.c_str());
+    doCommand(Doc,"App.activeDocument().%s.Force = 1.0",FeatName.c_str()); //OvG: set default not equal to 0
+    doCommand(Doc,"App.activeDocument().%s.Reversed = False",FeatName.c_str()); //OvG: set default to False
+    doCommand(Doc,"App.activeDocument().%s.Scale = 1",FeatName.c_str()); //OvG: set initial scale to 1
     doCommand(Doc,"App.activeDocument().%s.Member = App.activeDocument().%s.Member + [App.activeDocument().%s]",Analysis->getNameInDocument(),Analysis->getNameInDocument(),FeatName.c_str());
     updateActive();
 
@@ -392,7 +395,9 @@ void CmdFemConstraintPressure::activated(int iMsg)
 
     openCommand("Make FEM constraint pressure on face");
     doCommand(Doc,"App.activeDocument().addObject(\"Fem::ConstraintPressure\",\"%s\")",FeatName.c_str());
-    doCommand(Doc,"App.activeDocument().%s.Pressure = 0.0",FeatName.c_str());
+    doCommand(Doc,"App.activeDocument().%s.Pressure = 1000.0",FeatName.c_str()); //OvG: set default not equal to 0
+    doCommand(Doc,"App.activeDocument().%s.Reversed = False",FeatName.c_str()); //OvG: set default to False
+    doCommand(Doc,"App.activeDocument().%s.Scale = 1",FeatName.c_str()); //OvG: set initial scale to 1
     doCommand(Doc,"App.activeDocument().%s.Member = App.activeDocument().%s.Member + [App.activeDocument().%s]",
                              Analysis->getNameInDocument(),Analysis->getNameInDocument(),FeatName.c_str());
     updateActive();

src/Mod/Fem/Gui/TaskFemConstraint.cpp

@@ -56,6 +56,8 @@
 
 #include <Base/Console.h>
 
+# include <boost/lexical_cast.hpp> //OvG conversion between string and int etc.
+
 using namespace FemGui;
 using namespace Gui;
 
@@ -113,6 +115,14 @@ const std::string TaskFemConstraint::getReferences(const std::vector<std::string
     return result;
 }
 
+const std::string TaskFemConstraint::getScale() const //OvG: Return pre-calculated scale for constraint display
+{   
+    std::string result;
+    Fem::Constraint* pcConstraint = static_cast<Fem::Constraint*>(ConstraintView->getObject());
+    result = boost::lexical_cast<std::string>(pcConstraint->Scale.getValue());
+    return result;
+}
+
 void TaskFemConstraint::onReferenceDeleted(const int row) {
     Fem::Constraint* pcConstraint = static_cast<Fem::Constraint*>(ConstraintView->getObject());
     std::vector<App::DocumentObject*> Objects = pcConstraint->References.getValues();

src/Mod/Fem/Gui/TaskFemConstraint.h

@@ -42,6 +42,7 @@ public:
 
     virtual const std::string getReferences(void) const {return std::string();}
     const std::string getReferences(const std::vector<std::string>& items) const;
+    const std::string getScale() const;
 
 protected Q_SLOTS:
     void onReferenceDeleted(const int row);

src/Mod/Fem/Gui/TaskFemConstraintFixed.cpp

@@ -215,6 +215,10 @@ TaskDlgFemConstraintFixed::TaskDlgFemConstraintFixed(ViewProviderFemConstraintFi
 
 bool TaskDlgFemConstraintFixed::accept()
 {
+    std::string name = ConstraintView->getObject()->getNameInDocument();
+    const TaskFemConstraintFixed* parameterFixed = static_cast<const TaskFemConstraintFixed*>(parameter);
+    std::string scale = parameterFixed->getScale();  //OvG: determine modified scale
+    Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.Scale = %s", name.c_str(), scale.c_str()); //OvG: implement modified scale
     return TaskDlgFemConstraint::accept();
 }
 

src/Mod/Fem/Gui/TaskFemConstraintForce.cpp

@@ -352,10 +352,19 @@ bool TaskDlgFemConstraintForce::accept()
 
     try {
         //Gui::Command::openCommand("FEM force constraint changed");
-        Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.Force = %f",name.c_str(), parameterForce->getForce());
 
+        if (parameterForce->getForce()<=0)
+        {
+          QMessageBox::warning(parameter, tr("Input error"), tr("Please specify a force greater than 0"));  
+            return false;
+        }
+        else
+        {
+            Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.Force = %f",name.c_str(), parameterForce->getForce());
+        }
         std::string dirname = parameterForce->getDirectionName().data();
         std::string dirobj = parameterForce->getDirectionObject().data();
+        std::string scale = "1";
 
         if (!dirname.empty()) {
             QString buf = QString::fromUtf8("(App.ActiveDocument.%1,[\"%2\"])");
@@ -367,6 +376,9 @@ bool TaskDlgFemConstraintForce::accept()
         }
 
         Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.Reversed = %s", name.c_str(), parameterForce->getReverse() ? "True" : "False");
+        
+        scale = parameterForce->getScale();  //OvG: determine modified scale
+        Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.Scale = %s", name.c_str(), scale.c_str()); //OvG: implement modified scale
     }
     catch (const Base::Exception& e) {
         QMessageBox::warning(parameter, tr("Input error"), QString::fromLatin1(e.what()));

src/Mod/Fem/Gui/TaskFemConstraintPressure.cpp

@@ -249,12 +249,25 @@ bool TaskDlgFemConstraintPressure::accept()
 {
     std::string name = ConstraintView->getObject()->getNameInDocument();
     const TaskFemConstraintPressure* parameterPressure = static_cast<const TaskFemConstraintPressure*>(parameter);
+    std::string scale = "1";
 
     try {
-        Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.Pressure = %f",
+        if (parameterPressure->getPressure()<=0)
-            name.c_str(), parameterPressure->getPressure());
+        {
+          QMessageBox::warning(parameter, tr("Input error"), tr("Please specify a pressure greater than 0"));  
+            return false;
+        }
+        else
+        {
+            Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.Pressure = %f",
+            name.c_str(), parameterPressure->getPressure()); 
+        }
         Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.Reversed = %s",
             name.c_str(), parameterPressure->getReverse() ? "True" : "False");
+
+        scale = parameterPressure->getScale();  //OvG: determine modified scale
+        Gui::Command::doCommand(Gui::Command::Doc,"App.ActiveDocument.%s.Scale = %s",
+            name.c_str(), scale.c_str()); //OvG: implement modified scale
     }
     catch (const Base::Exception& e) {
         QMessageBox::warning(parameter, tr("Input error"), QString::fromLatin1(e.what()));

src/Mod/Fem/Gui/ViewProviderFemConstraintFixed.cpp

@@ -107,19 +107,22 @@ bool ViewProviderFemConstraintFixed::setEdit(int ModNum)
 
 #define HEIGHT 4
 #define WIDTH (1.5*HEIGHT)
-#define USE_MULTIPLE_COPY
+//#define USE_MULTIPLE_COPY  //OvG: MULTICOPY fails to update scaled display on initial drawing - so disable
 
 void ViewProviderFemConstraintFixed::updateData(const App::Property* prop)
 {
     // Gets called whenever a property of the attached object changes
     Fem::ConstraintFixed* pcConstraint = static_cast<Fem::ConstraintFixed*>(this->getObject());
+    float scaledwidth = WIDTH * pcConstraint->Scale.getValue(); //OvG: Calculate scaled values once only
+    float scaledheight = HEIGHT * pcConstraint->Scale.getValue();
 
 #ifdef USE_MULTIPLE_COPY
+    //OvG: always need access to cp for scaling
+    SoMultipleCopy* cp = new SoMultipleCopy();
     if (pShapeSep->getNumChildren() == 0) {
         // Set up the nodes
-        SoMultipleCopy* cp = new SoMultipleCopy();
         cp->matrix.setNum(0);
-        cp->addChild((SoNode*)createFixed(HEIGHT, WIDTH));
+        cp->addChild((SoNode*)createFixed(scaledheight, scaledwidth)); //OvG: Scaling
         pShapeSep->addChild(cp);
     }
 #endif
@@ -132,7 +135,7 @@ void ViewProviderFemConstraintFixed::updateData(const App::Property* prop)
         std::vector<Base::Vector3d>::const_iterator n = normals.begin();
 
 #ifdef USE_MULTIPLE_COPY
-        SoMultipleCopy* cp = static_cast<SoMultipleCopy*>(pShapeSep->getChild(0));
+        cp = static_cast<SoMultipleCopy*>(pShapeSep->getChild(0));
         cp->matrix.setNum(points.size());
         SbMatrix* matrices = cp->matrix.startEditing();
         int idx = 0;
@@ -153,7 +156,7 @@ void ViewProviderFemConstraintFixed::updateData(const App::Property* prop)
 #else
             SoSeparator* sep = new SoSeparator();
             createPlacement(sep, base, rot);
-            createFixed(sep, HEIGHT, WIDTH);
+            createFixed(sep, scaledheight, scaledwidth); //OvG: Scaling
             pShapeSep->addChild(sep);
 #endif
             n++;

src/Mod/Fem/Gui/ViewProviderFemConstraintForce.cpp

@@ -107,19 +107,22 @@ bool ViewProviderFemConstraintForce::setEdit(int ModNum)
 
 #define ARROWLENGTH 9
 #define ARROWHEADRADIUS (ARROWLENGTH/3)
-#define USE_MULTIPLE_COPY
+//#define USE_MULTIPLE_COPY  //OvG: MULTICOPY fails to update scaled arrows on initial drawing - so disable
 
 void ViewProviderFemConstraintForce::updateData(const App::Property* prop)
 {
     // Gets called whenever a property of the attached object changes
     Fem::ConstraintForce* pcConstraint = static_cast<Fem::ConstraintForce*>(this->getObject());
+    float scaledheadradius = ARROWHEADRADIUS * pcConstraint->Scale.getValue(); //OvG: Calculate scaled values once only
+    float scaledlength = ARROWLENGTH * pcConstraint->Scale.getValue();
 
 #ifdef USE_MULTIPLE_COPY
+    //OvG: need access to cp for scaling
+    SoMultipleCopy* cp = new SoMultipleCopy();
     if (pShapeSep->getNumChildren() == 0) {
         // Set up the nodes
-        SoMultipleCopy* cp = new SoMultipleCopy();
         cp->matrix.setNum(0);
-        cp->addChild((SoNode*)createArrow(ARROWLENGTH, ARROWHEADRADIUS));
+        cp->addChild((SoNode*)createArrow(scaledlength , scaledheadradius)); //OvG: Scaling
         pShapeSep->addChild(cp);
     }
 #endif
@@ -128,7 +131,7 @@ void ViewProviderFemConstraintForce::updateData(const App::Property* prop)
         const std::vector<Base::Vector3d>& points = pcConstraint->Points.getValues();
 
 #ifdef USE_MULTIPLE_COPY
-        SoMultipleCopy* cp = static_cast<SoMultipleCopy*>(pShapeSep->getChild(0));
+        cp = static_cast<SoMultipleCopy*>(pShapeSep->getChild(0));
         cp->matrix.setNum(points.size());
         SbMatrix* matrices = cp->matrix.startEditing();
         int idx = 0;
@@ -150,7 +153,7 @@ void ViewProviderFemConstraintForce::updateData(const App::Property* prop)
         for (std::vector<Base::Vector3d>::const_iterator p = points.begin(); p != points.end(); p++) {
             SbVec3f base(p->x, p->y, p->z);
             if (forceDirection.GetAngle(normal) < M_PI_2) // Move arrow so it doesn't disappear inside the solid
-                base = base + dir * ARROWLENGTH;
+                base = base + dir * scaledlength; //OvG: Scaling
 #ifdef USE_MULTIPLE_COPY
             SbMatrix m;
             m.setTransform(base, rot, SbVec3f(1,1,1));
@@ -159,7 +162,7 @@ void ViewProviderFemConstraintForce::updateData(const App::Property* prop)
 #else
             SoSeparator* sep = new SoSeparator();
             createPlacement(sep, base, rot);
-            createArrow(sep, ARROWLENGTH, ARROWHEADRADIUS);
+            createArrow(sep, scaledlength, scaledheadradius); //OvG: Scaling
             pShapeSep->addChild(sep);
 #endif
         }
@@ -189,7 +192,7 @@ void ViewProviderFemConstraintForce::updateData(const App::Property* prop)
         for (std::vector<Base::Vector3d>::const_iterator p = points.begin(); p != points.end(); p++) {
             SbVec3f base(p->x, p->y, p->z);
             if (forceDirection.GetAngle(normal) < M_PI_2)
-                base = base + dir * ARROWLENGTH;
+                base = base + dir * scaledlength; //OvG: Scaling
 #ifdef USE_MULTIPLE_COPY
             SbMatrix m;
             m.setTransform(base, rot, SbVec3f(1,1,1));
@@ -197,7 +200,7 @@ void ViewProviderFemConstraintForce::updateData(const App::Property* prop)
 #else
             SoSeparator* sep = static_cast<SoSeparator*>(pShapeSep->getChild(idx));
             updatePlacement(sep, 0, base, rot);
-            updateArrow(sep, 2, ARROWLENGTH, ARROWHEADRADIUS);
+            updateArrow(sep, 2, scaledlength, scaledheadradius); //OvG: Scaling
 #endif
             idx++;
         }

src/Mod/Fem/Gui/ViewProviderFemConstraintPressure.cpp

@@ -89,21 +89,27 @@ bool ViewProviderFemConstraintPressure::setEdit(int ModNum)
     }
 }
 
-#define ARROWLENGTH 5
+#define ARROWLENGTH (6)
-#define ARROWHEADRADIUS 3
+#define ARROWHEADRADIUS (ARROWLENGTH/3) 
+//#define USE_MULTIPLE_COPY //OvG: MULTICOPY fails to update scaled arrows on initial drawing - so disable
 
 void ViewProviderFemConstraintPressure::updateData(const App::Property* prop)
 {
     // Gets called whenever a property of the attached object changes
     Fem::ConstraintPressure* pcConstraint = static_cast<Fem::ConstraintPressure*>(this->getObject());
+    float scaledheadradius = ARROWHEADRADIUS * pcConstraint->Scale.getValue(); //OvG: Calculate scaled values once only
+    float scaledlength = ARROWLENGTH * pcConstraint->Scale.getValue();
 
+#ifdef USE_MULTIPLE_COPY
+    //OvG: always need access to cp for scaling
+    SoMultipleCopy* cp = new SoMultipleCopy();
     if (pShapeSep->getNumChildren() == 0) {
         // Set up the nodes
-        SoMultipleCopy* cp = new SoMultipleCopy();
         cp->matrix.setNum(0);
-        cp->addChild((SoNode*)createArrow(ARROWLENGTH, ARROWHEADRADIUS));
+        cp->addChild((SoNode*)createArrow(scaledlength , scaledheadradius)); //OvG: Scaling
         pShapeSep->addChild(cp);
     }
+#endif
 
     if (strcmp(prop->getName(),"Points") == 0) {
         const std::vector<Base::Vector3d>& points = pcConstraint->Points.getValues();
@@ -113,29 +119,43 @@ void ViewProviderFemConstraintPressure::updateData(const App::Property* prop)
         }
         std::vector<Base::Vector3d>::const_iterator n = normals.begin();
 
-        SoMultipleCopy* cp = static_cast<SoMultipleCopy*>(pShapeSep->getChild(0));
+#ifdef USE_MULTIPLE_COPY      
+        cp = static_cast<SoMultipleCopy*>(pShapeSep->getChild(0)); //OvG: Use top cp
         cp->matrix.setNum(points.size());
         SbMatrix* matrices = cp->matrix.startEditing();
         int idx = 0;
+#else
+        // Redraw all arrows
+        pShapeSep->removeAllChildren();
+#endif
 
         for (std::vector<Base::Vector3d>::const_iterator p = points.begin(); p != points.end(); p++) {
             SbVec3f base(p->x, p->y, p->z);
             SbVec3f dir(n->x, n->y, n->z);
             double rev;
             if (pcConstraint->Reversed.getValue()) {
-                base = base + dir * ARROWLENGTH;
+                base = base + dir * scaledlength; //OvG: Scaling
                 rev = 1;
             } else {
                 rev = -1;
             }
             SbRotation rot(SbVec3f(0, rev, 0), dir);
+#ifdef USE_MULTIPLE_COPY
             SbMatrix m;
             m.setTransform(base, rot, SbVec3f(1,1,1));
             matrices[idx] = m;
             idx++;
+#else
+            SoSeparator* sep = new SoSeparator();
+            createPlacement(sep, base, rot);
+            createArrow(sep, scaledlength , scaledheadradius); //OvG: Scaling
+            pShapeSep->addChild(sep);
+#endif
             n++;
         }
+#ifdef USE_MULTIPLE_COPY
         cp->matrix.finishEditing();
+#endif
     }
 
     ViewProviderFemConstraint::updateData(prop);