Merge pull request #2 from Linloir/boundingBox

Bounding box

FinalProject/model.cpp

@@ -34,6 +34,8 @@ void Model::loadModel(std::string path) {
     processNode(scene->mRootNode, scene);
     _status = LOADED;
     Logger::info("Model loaded");
+    // 仅检查一次即可
+    //check_boundary();
 }
 
 void Model::processNode(aiNode* node, const aiScene* scene) {
@@ -65,9 +67,16 @@ Mesh Model::processMesh(aiMesh* mesh, const aiScene* scene) {
         glm::vec3 vertexBitangent = glm::vec3(0.0f);
         
         // Process vertex positions
-        vertexPosition.x = mesh->mVertices[i].x;
-        vertexPosition.y = mesh->mVertices[i].y;
-        vertexPosition.z = mesh->mVertices[i].z;
+        //使用循环避免代码重复，如果可行的话，可以在此循环中确定法向量等信息
+        for (int j = 0; j < 3; j++) {
+            vertexPosition[j] = mesh->mVertices[i][j];
+            _left_down_back[j] = _left_down_back[j] < vertexPosition[j] ? _left_down_back[j] : vertexPosition[j];
+            _right_up_front[j] = _right_up_front[j] > vertexPosition[j] ? _right_up_front[j] : vertexPosition[j];
+        }
+
+        //vertexPosition.x = mesh->mVertices[i].x;
+        //vertexPosition.y = mesh->mVertices[i].y;
+        //vertexPosition.z = mesh->mVertices[i].z;
 
         // Process vertex normals
         if (mesh->mNormals) {
@@ -177,3 +186,19 @@ void Model::render(const ShaderProgram& shader) const {
         _meshes[i].render(shader);
     }
 }
+
+void Model::check_boundary() {
+    for (int i = 0; i < _meshes.size(); i++) {
+        for (int j = 0; j < _meshes[i].vertices().size();j++) {
+            // 0,1,2 for x,y,z
+            for (int k = 0; k < 3; k++) {
+                _left_down_back[k] = _left_down_back[k] < _meshes[i].vertices()[j]._position[k] ?
+                    _left_down_back[k] : _meshes[i].vertices()[j]._position[k];
+
+                _right_up_front[k] = _right_up_front[k] > _meshes[i].vertices()[j]._position[k] ?
+                    _right_up_front[k] : _meshes[i].vertices()[j]._position[k];
+            }
+        }
+    }
+
+}

FinalProject/model.h

@@ -8,7 +8,7 @@
 
 #include "mesh.h"
 #include "shader.h"
-
+#include <limits>
 class Model {
 public:
     enum MODELSTATUS { LOADING, LOADED, ERR };
@@ -19,6 +19,11 @@ private:
     std::string _directory;
     MODELSTATUS _status = LOADING;
 
+    // smallest point
+    glm::vec3 _left_down_back = glm::vec3(3e36f, 3e36f, 3e36f);
+    // largest point
+    glm::vec3 _right_up_front = -_left_down_back;
+
 public:
     Model(std::string path);
     ~Model();
@@ -26,12 +31,31 @@ public:
 public:
     inline MODELSTATUS status() const { return _status; }
 
+
+    // maybe we can check if boundary has not been set yet
+    // Do remember to ensure you have called check_boundary
+    inline glm::vec3 get_upper_bound() {
+        return _right_up_front;
+    }
+
+    // Do remember to ensure you have called check_boundary
+    inline glm::vec3 get_lower_bound() {
+        return _left_down_back;
+    }
+
 private:
     void loadModel(std::string path);
     void processNode(aiNode* node, const aiScene* scene);
     Mesh processMesh(aiMesh* mesh, const aiScene* scene);
     std::vector<Texture> loadMaterialTextures(aiMaterial* mat, aiTextureType type, TextureType textureType);
+    // Since these are loacl position, this function should be called just once.
+    void check_boundary();
 
 public:
     void render(const ShaderProgram& shader) const;
+
+    
+
+    // maybe we can encapsure a function to get both upper and lower bound?
+
 };

FinalProject/renderable.cpp

@@ -2,6 +2,8 @@
 
 #include "renderable.h"
 
+// 极值点一定在model包围盒的顶点处取到
+
 Renderable::Renderable(Model* model) : _model(model) {}
 
 Renderable::Renderable(Model* model, glm::vec3 position) : _model(model), _position(position) {}
@@ -36,3 +38,22 @@ void Renderable::render(ShaderProgram shader) {
     // Render
     _model->render(shader);
 }
+
+// check here to get global boundary
+// must check before get boundary
+void Renderable::check_boundary() {
+    std::vector<glm::vec3> temp = {_model->get_upper_bound(),_model->get_lower_bound()};
+    _lower_bound = glm::vec3(3e36, 3e36, 3e36);
+    _upper_bound = -_lower_bound;
+    auto model = this->modelMatrix();// 变换矩阵
+    // 位运算 从000到111的每一种组合
+    for (int i = 0; i < 8; i++) {
+        //遍历每一个顶点
+        glm::vec4 vx = glm::vec4(temp[(i & 4) >> 2][0], temp[(i & 2)>>1][1], temp[i & 1][2], 1.0f);
+        auto vex = model * vx; // 经过变化之后的点的坐标
+        for (int j = 0; j < 3; j++) {
+            _lower_bound[j] = _lower_bound[j] < vex[j] ? _lower_bound[j] : vex[j];
+            _upper_bound[j] = _upper_bound[j] > vex[j] ? _upper_bound[j] : vex[j];
+        }
+    }
+}

FinalProject/renderable.h

@@ -12,6 +12,9 @@ private:
     glm::vec3 _position = glm::vec3(0.0f);
     glm::mat4 _rotation = glm::mat4(1.0f);
     glm::vec3 _scale = glm::vec3(1.0f);
+    // 下面是与坐标轴平行的顶点
+    glm::vec3 _lower_bound;
+    glm::vec3 _upper_bound;
 
 public:
     Renderable(Model* model);
@@ -27,14 +30,28 @@ public:
 
     inline glm::mat4 modelMatrix() const;
 
+    inline glm::vec3 get_upper_boundary()const;
+    inline glm::vec3 get_lower_boundary()const;
+
 public:
     void render(ShaderProgram shader);
+    // check here to get global boundary
+    void check_boundary();
 };
 
 inline glm::mat4 Renderable::modelMatrix() const {
     glm::mat4 model = glm::mat4(1.0f);
     model = glm::translate(model, _position);
-    model = model * _rotation;
+    // 左乘与右乘应该是不一样的，但是这里的表现相同
+    //model = model * _rotation;
+    model = _rotation * model;
     model = glm::scale(model, _scale);
     return model;
 }
+
+inline glm::vec3 Renderable::get_lower_boundary()const {
+    return _lower_bound;
+}
+inline glm::vec3 Renderable::get_upper_boundary()const {
+    return _upper_bound;
+}

FinalProject/sceneviewer.cpp

@@ -65,12 +65,14 @@ void SceneViewer::initializeGL() {
     vertexShader.dispose();
     fragmentShader.dispose();
 
-    Model* backpackModel = new Model("E:\\Repositories\\CollegeProjects\\CGAssignments\\FinalProject\\Models\\backpack\\backpack.obj");
+    Model* backpackModel = new Model("D:/code/ComputerGraphic/SceneEditor/obj/nanosuit/nanosuit.obj");
     Logger::info("Model loaded");
     Renderable backpack(backpackModel);
     _objects.push_back(backpack);
     
+
     _camera.setPosition(glm::vec3(0.0f, 0.0f, 5.0f));
+
 }
 
 void SceneViewer::resizeGL(int w, int h) {