Add hang effect for cloth simulation

languages/dust3d_zh_CN.ts

@@ -754,7 +754,7 @@ Tips:
     </message>
     <message>
         <source>Stiffness</source>
-        <translation type="unfinished"></translation>
+        <translation>硬度</translation>
     </message>
 </context>
 <context>

src/clothsimulator.cpp

@@ -111,6 +111,19 @@ public:
             }
         }
     }
+    
+    void fixPoints(CgPointFixNode *fixNode) {
+        for (unsigned int i = 0; i < system->n_points; i++) {
+            auto offset = 3 * i;
+            Point point(vbuff[offset + 0],
+                vbuff[offset + 1],
+                vbuff[offset + 2]);
+            if (nullptr != m_insideTester &&
+                    (*m_insideTester)(point) != CGAL::ON_UNBOUNDED_SIDE) {
+                fixNode->fixPoint(i);
+            }
+        }
+    }
 };
 
 ClothSimulator::ClothSimulator(const std::vector<QVector3D> &vertices,
@@ -131,6 +144,7 @@ ClothSimulator::~ClothSimulator()
     delete m_rootNode;
     delete m_deformationNode;
     delete m_meshCollisionNode;
+    delete m_fixNode;
 }
 
 void ClothSimulator::setStiffness(float stiffness)
@@ -243,5 +257,10 @@ void ClothSimulator::create()
     m_meshCollisionNode = new CgMeshCollisionNode(m_massSpringSystem, m_clothPointBuffer.data(),
         m_collisionVertices,
         m_collisionTriangles);
+    
+    m_fixNode = new CgPointFixNode(m_massSpringSystem, m_clothPointBuffer.data());
+    m_meshCollisionNode->fixPoints(m_fixNode);
+    m_deformationNode->addChild(m_fixNode);
+    
     m_rootNode->addChild(m_meshCollisionNode);
 }

src/clothsimulator.h

@@ -9,6 +9,7 @@ class MassSpringSolver;
 class CgRootNode;
 class CgSpringDeformationNode;
 class CgMeshCollisionNode;
+class CgPointFixNode;
 
 class ClothSimulator : public QObject
 {
@@ -37,6 +38,7 @@ private:
     CgRootNode *m_rootNode = nullptr;
     CgSpringDeformationNode *m_deformationNode = nullptr;
     CgMeshCollisionNode *m_meshCollisionNode = nullptr;
+    CgPointFixNode *m_fixNode = nullptr;
     void convertMeshToCloth();
 };