glm库变换和坐标系统

glm::mat4 xxx

glm::mat4 model = glm::mat4(1.0f); 
glm::mat4 view = glm::mat4(1.0f);
glm::mat4 projection = glm::mat4(1.0f);

glm::rotate glm::translate glm::perspective

model = glm::rotate(model, (float)glfwGetTime(), glm::vec3(1.0f, 0.0f, 0.0f));
view = glm::translate(view, glm::vec3(0.0f, 0.0f, -3.0f));
projection = glm::perspective(glm::radians(45.0f), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);

实质：

• 模型变换：进行旋转操作——旋转到和世界坐标方向一样
• 观察变换：进行位移操作——相机移动=场景的反方向移动
• 投影变换：透视操作