OpenGL 使用 Q 和 E 字符移动相机 GLFW 库

Posted 2023-02-16

【中文标题】OpenGL 使用 Q 和 E 字符移动相机 GLFW 库

【英文标题】：OpenGL use Q and E characters to move camera GLFW libraries

【发布时间】：2021-05-30 17:29:54

【问题描述】：

我无法找出正确的命令来添加到此并让 Q 和 E 命令直接上下移动相机。我尝试了很多方法都没有成功。

void processInput(GLFWwindow *window)

    if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
        glfwSetWindowShouldClose(window, true);

    float cameraSpeed = 2.5 * deltaTime;
    if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
        cameraPos += cameraSpeed * cameraFront;
    if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
        cameraPos -= cameraSpeed * cameraFront;
    if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
        cameraPos -= glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed;
    if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
        cameraPos += glm::normalize(glm::cross(cameraFront, cameraUp)) * cameraSpeed;

【问题讨论】：

大概和 W/S 是一样的，只不过是用cameraUp 而不是cameraFront。

cameraUp 是否垂直于cameraFront？

问题解决了吗？请阅读What should I do when someone answers my question?

【参考方案1】：

如果cameraUp 垂直于cameraFront：

if (glfwGetKey(window, GLFW_KEY_Q) == GLFW_PRESS)
    cameraPos -= cameraSpeed * cameraUp;
if (glfwGetKey(window, GLFW_KEY_E) == GLFW_PRESS)
    cameraPos += cameraSpeed * cameraUp;

如果cameraUp 不（完全）垂直于cameraFront，则必须计算由cross(cameraFront, cameraUp) 和cameraFront 定义的平面上的法线向量：

glm::vec3 lateral_vector = glm::normalize(glm::cross(cameraFront, cameraUp));
glm::vec3 up_vector = glm::normalize(glm::cross(lateral_vector, cameraFront));

if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
    cameraPos -= cameraSpeed * cameraFront;
if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
    cameraPos += cameraSpeed * cameraFront;
if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
    cameraPos -= cameraSpeed * lateral_vector;
if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
    cameraPos += cameraSpeed * lateral_vector;
if (glfwGetKey(window, GLFW_KEY_Q) == GLFW_PRESS)
    cameraPos -= cameraSpeed * up_vector;
if (glfwGetKey(window, GLFW_KEY_E) == GLFW_PRESS)
    cameraPos += cameraSpeed * up_vector;

【参考方案2】：

if (glfwGetKey(window, GLFW_KEY_Q) == GLFW_PRESS)
    gCameraPos -= cameraSpeed * gCameraUp * cameraOffset;
if (glfwGetKey(window, GLFW_KEY_E) == GLFW_PRESS)
    gCameraPos += cameraSpeed * gCameraUp * cameraOffset;

【讨论】：

虽然此代码可能会回答问题，但提供有关它如何和/或为什么解决问题的额外上下文将提高​​答案的长期价值。谢谢！