我有一个相机类，它是这样初始化的:

CameraFP::CameraFP()  {
    this->aspect_ratio = 800.0f / 600.0f;
    this->fov = 45.0f;
    this->near_plane = 0.1f;
    this->far_plane = 1000.0f;
    this->position = glm::vec3(0, 0, 0);
    this->target = position + glm::vec3(0, 0, -1);
    this->up = glm::vec3(0, 1, 0);
    this->m_rotation = glm::mat4(1.0);

    m_view = glm::lookAt(position, target, up);
    m_projection = glm::perspective(fov, aspect_ratio, near_plane, far_plane);
}

这里是import的其他函数:

void CameraFP::update(sf::Window *app)  {
    process_keyboard(app);
    process_mouse(app);

    calculate_view();
}

void CameraFP::process_keyboard(sf::Window *app)  {
    const sf::Input *input = &app->GetInput();

    up = m_rotation * glm::vec3(0, 1, 0);

    glm::vec3 forward = glm::vec3(0, 0, -1);
    glm::vec3 forward_rotated = m_rotation * forward;

    glm::vec3 right = glm::vec3(1, 0, 0);
    glm::vec3 right_rotated = m_rotation * right;

    if (input->IsKeyDown(sf::Key::W))  {
        position += forward_rotated;
    }
    if (input->IsKeyDown(sf::Key::S))  {
        position -= forward_rotated;
    }
    if (input->IsKeyDown(sf::Key::A))  {
        position -= right_rotated;
    }
    if (input->IsKeyDown(sf::Key::D))  {
        position += right_rotated;
    }
}

void CameraFP::process_mouse(sf::Window *app)  {
    // TODO: Make the below constants, and take framerate into account
    GLfloat SPEED_X = 0.000001f;
    GLfloat SPEED_Y = 0.000001f;

    GLfloat mouse_x = app->GetInput().GetMouseX();
    GLfloat mouse_y = app->GetInput().GetMouseY();

    GLfloat mouse_x_delta = old_mouse_x - mouse_x;
    GLfloat mouse_y_delta = old_mouse_y - mouse_y;

    if (mouse_x_delta != 0 ||
        mouse_y_delta != 0)  {
        if (mouse_x_delta != 0)  {
            y_rot += mouse_x_delta * SPEED_X;

            m_rotation = glm::rotate(m_rotation, y_rot, glm::vec3(0, 1, 0));
        }
        if (mouse_y_delta != 0)  {
            x_rot += mouse_y_delta * SPEED_Y;

            m_rotation = glm::rotate(m_rotation, x_rot, glm::vec3(1, 0, 0));;
        }
    }

    this->old_mouse_x = mouse_x;
    this->old_mouse_y = mouse_y;

    app->SetCursorPosition(app->GetWidth() / 2, app->GetHeight() / 2);
}


void CameraFP::calculate_view()  {
    glm::vec3 forward = glm::vec3(0, 0, -1);
    glm::vec3 forward_rotated = m_rotation * forward;

    target = position += glm::normalize(forward_rotated);

    m_view = glm::lookAt(position, target, up);
}

我的问题是，当我编译项目时，编译器输出错误信息:

\CameraFP.cpp|59|error: no match for 'operator*' in '((CameraFP*)this)->CameraFP::m_rotation * glm::detail::tvec3<float>(((const int&)((const int*)(&0))), ((const int&)((const int*)(&1))), ((const int&)((const int*)(&0))))'|

根据我的理解，vec = mat4 * vec 应该产生一个旋转 vector ？由于我无法测试此代码，因此我不知道该功能是否正常工作。

编辑

根据评论和 awnsers 更新了代码。我现在的问题是我在渲染函数的某处出现了蓝屏死机...

void CameraFP::process_keyboard(sf::Window *app)  {
    const sf::Input *input = &app->GetInput();

    up = m_rotation * glm::vec4(0.0f, 1.0f, 0.0f, 0.0f);

    glm::vec4 forward = glm::vec4(0.0f, 0.0f, -1.0f, 0.0f);
    glm::vec4 forward_rotated = m_rotation * forward;

    glm::vec4 right = glm::vec4(1.0f, 0.0f, 0.0f, 0.0f);
    glm::vec4 right_rotated = m_rotation * right;

    if (input->IsKeyDown(sf::Key::W))  {
        position += forward_rotated;
    }
    if (input->IsKeyDown(sf::Key::S))  {
        position -= forward_rotated;
    }
    if (input->IsKeyDown(sf::Key::A))  {
        position -= right_rotated;
    }
    if (input->IsKeyDown(sf::Key::D))  {
        position += right_rotated;
    }
}

void CameraFP::process_mouse(sf::Window *app)  {
    // TODO: Make the below constants, and take framerate into account
    GLfloat SPEED_X = 0.000001f;
    GLfloat SPEED_Y = 0.000001f;

    GLfloat mouse_x = app->GetInput().GetMouseX();
    GLfloat mouse_y = app->GetInput().GetMouseY();

    GLfloat mouse_x_delta = old_mouse_x - mouse_x;
    GLfloat mouse_y_delta = old_mouse_y - mouse_y;

    if (mouse_x_delta != 0 ||
        mouse_y_delta != 0)  {
        if (mouse_x_delta != 0)  {
            y_rot += mouse_x_delta * SPEED_X;

            m_rotation = glm::rotate(m_rotation, y_rot, glm::vec3(0.0f, 1.0f, 0.0f));
        }
        if (mouse_y_delta != 0)  {
            x_rot += mouse_y_delta * SPEED_Y;

            m_rotation = glm::rotate(m_rotation, x_rot, glm::vec3(1.0f, 0.0f, 0.0f));;
        }
    }

    this->old_mouse_x = mouse_x;
    this->old_mouse_y = mouse_y;

    app->SetCursorPosition(app->GetWidth() / 2, app->GetHeight() / 2);
}

void CameraFP::calculate_view()  {
    glm::vec4 forward = glm::vec4(0.0f, 0.0f, -1.0f, 0.0f);
    glm::vec4 forward_rotated = m_rotation * forward;

    target = position += forward_rotated;

    m_view = glm::lookAt(v4tov3(position), v4tov3(target), v4tov3(up));
}

glm::vec3 v4tov3(glm::vec4 v1)  {
    return glm::vec3(v1.x, v1.y, v1.z);
}

编辑2

现在的问题是用鼠标旋转相机，它根本不起作用，由于某些原因，x 轴上的变化经常会影响 y 轴的变化，反之亦然。此外，如果我在 x 轴上向右或向左移动鼠标(y 旋转)，相机将向左旋转...

void CameraFP::process_mouse(sf::Clock *clock, sf::Window *app)  {
    // TODO: Make the below constants, and take framerate into account
    GLfloat SPEED_X = 0.25f;
    GLfloat SPEED_Y = 0.25f;

    GLfloat screen_x = app->GetWidth();
    GLfloat screen_y = app->GetHeight();

    GLfloat mouse_x = float(screen_x / 2 - app->GetInput().GetMouseX());
    GLfloat mouse_y = float(screen_y / 2 - app->GetInput().GetMouseY());

    GLfloat mouse_x_delta = old_mouse_x - mouse_x;
    GLfloat mouse_y_delta = old_mouse_y - mouse_y;

    GLfloat current_time = clock->GetElapsedTime();
    GLfloat delta_time = current_time - last_time;

    this->last_time = current_time;

    if (mouse_x_delta != 0 ||
        mouse_y_delta != 0)  {
        if (mouse_x_delta != 0)  {
            y_rot += glm::radians(delta_time * SPEED_X * mouse_x);

            m_rotation = glm::rotate(m_rotation, y_rot, glm::vec3(0.0f, 1.0f, 0.0f));

            std::cout << "Y Rotation: " << y_rot << "\n";
        }
        if (mouse_y_delta != 0)  {
            x_rot += glm::radians(delta_time * SPEED_Y * mouse_y);

            m_rotation = glm::rotate(m_rotation, x_rot, glm::vec3(1.0f, 0.0f, 0.0f));

            std::cout << "X rotation: " << x_rot << "\n";
        }
    }

    app->SetCursorPosition(screen_x / 2, screen_y / 2);

    this->old_mouse_x = float(screen_x / 2 - app->GetInput().GetMouseX());
    this->old_mouse_y = float(screen_y / 2 - app->GetInput().GetMouseY());
}

最佳答案

替换所有的 glm::vec3(0, 1, 0);通过 glm::vec3(0.0f, 1.0f, 0.0f);

至于 vec-mac 乘法，AquilaRapax 是正确的，因为你只能将 mat4 与 vec4 相乘。但是因为你乘以方向，第 4r 个坐标应该是 0.0f，而不是 1.0f。这将产生忽略翻译的效果(1.0 会将它们考虑在内，这是你不想要的)

参见 http://www.opengl-tutorial.org/beginners-tutorials/tutorial-3-matrices/有关矩阵的详细信息。

但是，保留 vec3 而不是 vec4 通常是个好主意，主要是为了清楚起见(即，glm::vec3 mPosition 而不是 glm::vec4 mPosition)。因此，拥有像这样的 2 个函数(未经测试)是很方便的:

glm::vec3 TransformDirection(glm::vec3 pDirection, glm::mat4 pMatrix){
    return pMatrix * glm::vec4(pDirection, 0.0f);
}

glm::vec3 TransformPosition(glm::vec3 pDirection, glm::mat4 pMatrix){
    return pMatrix * glm::vec4(pDirection, 1.0f);
}

关于c++ - 使用 GLM 正确旋转 Open GL 相机，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/12138721/