1 //摄像机的位置 2 //不要忘记z轴是从屏幕指向你的，如果我们希望摄像机向后移动，我们就沿着z轴的正方向移动 3 glm::vec3 cameraPos = glm::vec3(0.0f, 0.0f, 3.0f); 4 glm::vec3 cameraTarget = glm::vec3(0.0f, 0.0f, 0.0f); 5 glm::vec3 cameraDirection = glm::normalize(cameraPos - cameraTarget);//这个方向是物体指向摄像机的方向（方向向量） 6 7 //右轴，右向量（right vector>，它代表摄像机空间的x轴的正方向， 8 //定义方法：先定义一个上向量（up vector)，接下来把上向量的上一步得到的方向向量进行叉乘 9 glm::vec3 up = glm::vec3(0.0f, 1.0f, 0.0f); 10 glm::vec3 cameraRight = glm::normalize(glm::cross(up, cameraDirection)); 11 12 //上轴，将右轴和方向向量进行叉乘 13 glm::vec3 cameraUp = glm::cross(cameraDirection, cameraRight); 14 15 16 //lookAt矩阵 17 //我们只需提供一个摄像机位置，目标物体位置，和一个上向量，glm::lookAt就会为我们自动生成一个lookAt矩阵，即一个观察矩阵 18 glm::mat4 view; 19 view = glm::lookAt(glm::vec3(0.0f, 0.0f, 3.0f), 20 glm::vec3(0.0f, 0.0f, 0.0f), 21 glm::vec3(0.0f, 1.0f, 0.0f));
摄像机自动移动
1 float radius = 10.0f; 2 float camX = sin(glfwGetTime()) * radius; 3 float camZ = cos(glfwGetTime())* radius; 4 glm::mat4 view; 5 view = glm::lookAt(glm::vec3(camX, 0.0, camZ), 6 glm::vec3(0.0f, 0.0f, 0.0f), 7 glm::vec3(0.0f, 1.0f, 0.0f)); 8 glUniformMatrix4fv(glGetUniformLocation(ourShader.ID, "view"), 1, GL_FALSE, glm::value_ptr(view));
用WASD控制摄像机的前后左右移动
1 glm::vec3 cameraPos = glm::vec3(0.0, 0.0f, 5.0f); 2 glm::vec3 cameraFront = glm::vec3(0.0f, 0.0f, -1.0f); 3 glm::vec3 cameraUp = glm::vec3(0.0f, 1.0f, 0.0f); 4 glm::mat4 view = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp); 5 glUniformMatrix4fv(glGetUniformLocation(ourShader.ID, "view"), 1, GL_FALSE, glm::value_ptr(view)); 6 void processInput(GLFWwindow* window) 7 { 8 9 float cameraSpeed = 0.5f; 10 if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS) 11 cameraPos += cameraSpeed * cameraFront; 12 if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS) 13 cameraPos -= cameraSpeed * cameraFront; 14 if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS) 15 cameraPos -= glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed; 16 if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS) 17 cameraPos += glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed; 18 19 }
