
OpenGL模型加载-附源码
效果:

摘要:
使用ssimp并创建实际的加载和转换。目标是创建另一个类来完整地表示一个模型,或者说是包含多个网格,甚至是多个物体的模型。一个包含木制阳台、塔楼、甚至游泳池的房子可能仍会被加载为一个模型。我们会使用Assimp来加载模型,并将它转换(Translate)至多个Mesh对象。
首先需要调用的函数是loadModel,它会从构造器中直接调用。在loadModel中,我们使用Assimp来加载模型至Assimp的一个叫做scene的数据结构中。一旦我们有了这个场景对象,我们就能访问到加载后的模型中所有所需的数据了。
主要代码:
//#define STB_IMAGE_IMPLEMENTATION #include "glad.c" #include <glad/glad.h> #include <GLFW/glfw3.h> #include <glm/glm.hpp> #include <glm/gtc/matrix_transform.hpp> #include <glm/gtc/type_ptr.hpp> #include <learnopengl/shader_m.h> #include <learnopengl/camera.h> #include <learnopengl/model.h> #include <iostream> void framebuffer_size_callback(GLFWwindow* window, int width, int height); void mouse_callback(GLFWwindow* window, double xpos, double ypos); void scroll_callback(GLFWwindow* window, double xoffset, double yoffset); void processInput(GLFWwindow *window); // settings const unsigned int SCR_WIDTH = 800; const unsigned int SCR_HEIGHT = 600; // camera Camera camera(glm::vec3(0.0f, 4.0f, 6.0f)); float lastX = SCR_WIDTH / 2.0f; float lastY = SCR_HEIGHT / 2.0f; bool firstMouse = true; // timing float deltaTime = 0.0f; float lastFrame = 0.0f; int main() { // glfw: initialize and configure // ------------------------------ glfwInit(); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); #ifdef __APPLE__ glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); #endif // glfw window creation // -------------------- GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL); if (window == NULL) { std::cout << "Failed to create GLFW window" << std::endl; glfwTerminate(); return -1; } glfwMakeContextCurrent(window); glfwSetFramebufferSizeCallback(window, framebuffer_size_callback); glfwSetCursorPosCallback(window, mouse_callback); glfwSetScrollCallback(window, scroll_callback); // tell GLFW to capture our mouse glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED); // glad: load all OpenGL function pointers // --------------------------------------- if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress)) { std::cout << "Failed to initialize GLAD" << std::endl; return -1; } // tell stb_image.h to flip loaded texture's on the y-axis (before loading model). stbi_set_flip_vertically_on_load(true); // configure global opengl state // ----------------------------- glEnable(GL_DEPTH_TEST); // build and compile shaders // ------------------------- Shader lightingShader("5.1.light_casters.vs", "5.1.light_casters.fs"); // build and compile shaders // ------------------------- //Shader ourShader("1.model_loading.vs", "1.model_loading.fs"); // load models // ----------- Model ourModel("resources/objects/cyborg/cyborg.obj"); // draw in wireframe //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); // -------------------- lightingShader.use(); lightingShader.setInt("material.diffuse", 0); lightingShader.setInt("material.specular", 1); // render loop // ----------- while (!glfwWindowShouldClose(window)) { // per-frame time logic // -------------------- float currentFrame = glfwGetTime(); deltaTime = currentFrame - lastFrame; lastFrame = currentFrame; // input // ----- processInput(window); // render // ------ glClearColor(0.2f, 0.5f, 0.5f, 1.0f); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // be sure to activate shader when setting uniforms/drawing objects lightingShader.use(); lightingShader.setVec3("light.direction", -0.2f, -1.0f, -0.3f); lightingShader.setVec3("viewPos", camera.Position); // light properties lightingShader.setVec3("light.ambient", 0.9f, 0.9f, 0.9f); lightingShader.setVec3("light.diffuse", 0.5f, 0.5f, 0.5f); lightingShader.setVec3("light.specular", 1.0f, 1.0f, 1.0f); // material properties lightingShader.setFloat("material.shininess", 32.0f); // don't forget to enable shader before setting uniforms //lightingShader.use(); // view/projection transformations glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f); glm::mat4 view = camera.GetViewMatrix(); lightingShader.setMat4("projection", projection); lightingShader.setMat4("view", view); // render the loaded model glm::mat4 model = glm::mat4(1.0f); model = glm::translate(model, glm::vec3(0.0f, 0.0f, 0.0f)); // translate it down so it's at the center of the scene model = glm::scale(model, glm::vec3(1.0f, 1.0f, 1.0f)); // it's a bit too big for our scene, so scale it down lightingShader.setMat4("model", model); ourModel.Draw(lightingShader); // glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.) // ------------------------------------------------------------------------------- glfwSwapBuffers(window); glfwPollEvents(); } // glfw: terminate, clearing all previously allocated GLFW resources. // ------------------------------------------------------------------ glfwTerminate(); return 0; } // process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly // --------------------------------------------------------------------------------------------------------- void processInput(GLFWwindow *window) { if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS) glfwSetWindowShouldClose(window, true); if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS) camera.ProcessKeyboard(FORWARD, deltaTime); if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS) camera.ProcessKeyboard(BACKWARD, deltaTime); if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS) camera.ProcessKeyboard(LEFT, deltaTime); if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS) camera.ProcessKeyboard(RIGHT, deltaTime); } // glfw: whenever the window size changed (by OS or user resize) this callback function executes // --------------------------------------------------------------------------------------------- void framebuffer_size_callback(GLFWwindow* window, int width, int height) { // make sure the viewport matches the new window dimensions; note that width and // height will be significantly larger than specified on retina displays. glViewport(0, 0, width, height); } // glfw: whenever the mouse moves, this callback is called // ------------------------------------------------------- void mouse_callback(GLFWwindow* window, double xpos, double ypos) { if (firstMouse) { lastX = xpos; lastY = ypos; firstMouse = false; } float xoffset = xpos - lastX; float yoffset = lastY - ypos; // reversed since y-coordinates go from bottom to top lastX = xpos; lastY = ypos; camera.ProcessMouseMovement(xoffset, yoffset); } // glfw: whenever the mouse scroll wheel scrolls, this callback is called // ---------------------------------------------------------------------- void scroll_callback(GLFWwindow* window, double xoffset, double yoffset) { camera.ProcessMouseScroll(yoffset); }
参考资料:
https://learnopengl-cn.github.io/03%20Model%20Loading/03%20Model/
完整的项目代码:
链接:https://pan.baidu.com/s/1IZbmCldx_4N4bAeeWhT2dA
提取码:vtbh