support auto build neighbor geometry

Author: Xayah-Hina

RenderingFrameWork/src/renderable.cpp

@@ -4,3 +4,74 @@
  */
 
 #include "renderable.h"
+
+void HINAVIEWER::RENDERABLE::Renderable::build_neighbors()
+{
+    if (V_.rows() == 0)
+        return;
+
+    int vertices_per_face = 3; // triangle mesh only
+
+    VE_.clear();
+    VF_.clear();
+    EVF_.clear();
+    FE_.clear();
+
+    VE_.resize(V_.rows());
+    VF_.resize(V_.rows());
+    FE_.resize(F_.rows());
+    EVF_.reserve(E_.rows());
+
+    for (int i = 0; i < F_.rows(); ++i)
+    {
+        FE_[i].resize(vertices_per_face);
+        for (int j = 0; j < vertices_per_face; ++j)
+        {
+            const unsigned int v_index = F_.row(i)(j);
+
+            bool found = false;
+            for (auto &face_index: VF_[v_index])
+            {
+                if (face_index == i)
+                {
+                    found = true;
+                    break;
+                }
+            }
+
+            if (!found)
+                VF_[v_index].emplace_back(i);
+
+            const unsigned int ev1 = F_.row(i)(j);
+            const unsigned int ev2 = F_.row(i)((j + 1) % 3);
+            unsigned int edge = 0xffffffff;
+            for (auto &edge_index: VE_[ev1])
+                if ((EVF_[edge_index][0] == ev1 || EVF_[edge_index][0] == ev2) && (EVF_[edge_index][1] == ev1 || EVF_[edge_index][1] == ev2))
+                    edge = edge_index;
+            if (edge == 0xffffffff)
+            {
+                EVF_.emplace_back(std::vector<unsigned int>({ev1, ev2, static_cast<unsigned int>(i), 0xffffffff}));
+                edge = EVF_.size() - 1;
+                VE_[ev1].emplace_back(edge);
+                VE_[ev2].emplace_back(edge);
+            } else
+                EVF_[edge][3] = i;
+
+            FE_[i][j] = edge;
+        }
+    }
+
+    E_.resize(EVF_.size(), 2);
+    for (int i = 0; i < EVF_.size(); ++i)
+        E_.row(i) = Eigen::RowVector2i(EVF_[i][0], EVF_[i][1]);
+
+    for (auto &evf: EVF_)
+    {
+        if (evf[3] == 0xffffffff)
+        {
+            is_closed_ = false;
+            return;
+        }
+    }
+    is_closed_ = true;
+}

RenderingFrameWork/src/renderable.h

@@ -8,6 +8,7 @@
 
 #include "../eigen_types.h"
 
+#include <vector>
 #include <string>
 
 namespace HINAVIEWER::RENDERABLE
@@ -17,14 +18,22 @@ namespace HINAVIEWER::RENDERABLE
     public:
         virtual void init_geometry(const std::string &path) = 0;
 
+        void build_neighbors();
+
     public:
         bool is_recorded_ = false;
         int ID_ = -1; // invalid unless recorded
 
     public:
-        Eigen::MatrixXd V_;
-        Eigen::MatrixXi F_;
-        Eigen::MatrixXi E_;
+        Eigen::MatrixXd V_; // Vertices - size = [#vertices x 3], row = [x, y, z]
+        Eigen::MatrixXi F_; // Faces - size = [#faces x 3], row = [v1_index, v2_index, v3_index]
+        Eigen::MatrixXi E_; // Edges - size = [#edges x 2], row = [v1_index, v2_index]
+
+        std::vector<std::vector<unsigned int>> VE_; // Vertex-edges - size = [#vertices x ?], row = [edge1_index, edge2_index, ... ...]
+        std::vector<std::vector<unsigned int>> VF_; // Vertex-faces - size = [#faces x ?], row = [face1_index, face2_index, ... ...]
+        std::vector<std::vector<unsigned int>> FE_; // Face-edges - size = [#faces x 3], row = [edge1_index, edge2_index, edge3_index]
+        std::vector<std::vector<unsigned int>> EVF_; // Edge-vertices-faces - size = [#edges x 4], row = [v1_index, v2_index, face1_index, face2_index]
+        bool is_closed_;
     };
 }
 

SimulationFrameWork/src/objects.cpp

@@ -5,9 +5,8 @@
 
 #include "objects.h"
 
-#include "cmake-build-release/_deps/libigl-src/include/igl/edges.h"
-#include "cmake-build-release/_deps/libigl-src/include/igl/readOBJ.h"
-#include "cmake-build-release/_deps/libigl-src/include/igl/readPLY.h"
+#include <igl/readOBJ.h>
+#include <igl/readPLY.h>
 
 void HINASIM::SimObject::init_geometry(const std::string &path)
 {
@@ -27,7 +26,7 @@ void HINASIM::SimObject::init_geometry(const std::string &path)
     else if (model_type == "ply")
         igl::readPLY(path, V_, F_);
 
-    igl::edges(F_, E_);
+    build_neighbors(); // Edges info would be auto build ourselves
 
     if (V_.rows() > 0)
         init_physical_state();
@@ -119,7 +118,7 @@ void HINASIM::Cloth::init_geometry()
 
     custom_init_geometry(V_, F_);
 
-    igl::edges(F_, E_);
+    build_neighbors(); // Edges info would be auto build ourselves
 
     if (V_.rows() > 0)
         init_physical_state();

SimulationFrameWork/test/main.cpp

@@ -30,7 +30,6 @@ int main()
     HINASIM::Cloth cloth(30, 30, 20, 20);
     cloth.init_geometry();
     HINASIM::DistanceConstraint dc_cloth(cloth.q_, cloth.E_);
-
     func(pbd_viewer, pbd_sim, cloth, dc_cloth);