glm::dmat4 LookAt(const glm::vec3& pos, const glm::vec3& look, const glm::vec3& up) {

    glm::dmat4 cameraToWorld;
    // Initialize fourth column of viewing matrix
    cameraToWorld[0][3] = pos.x;
    cameraToWorld[1][3] = pos.y;
    cameraToWorld[2][3] = pos.z;
    cameraToWorld[3][3] = 1;

    glm::vec3 dir = glm::normalize(look - pos);
    glm::vec3 left = glm::normalize(glm::cross(glm::normalize(up), dir));
    glm::vec3 newUp = glm::cross(dir, left);

    cameraToWorld[0][0] = left.x;
    cameraToWorld[1][0] = left.y;
    cameraToWorld[2][0] = left.z;
    cameraToWorld[3][0] = 0.;
    cameraToWorld[0][1] = newUp.x;
    cameraToWorld[1][1] = newUp.y;
    cameraToWorld[2][1] = newUp.z;
    cameraToWorld[3][1] = 0.;
    cameraToWorld[0][2] = dir.x;
    cameraToWorld[1][2] = dir.y;
    cameraToWorld[2][2] = dir.z;
    cameraToWorld[3][2] = 0.;

    return glm::inverse(cameraToWorld);
}