Question

我正在尝试构建一个光线跟踪器，并使用AKKA-http deployment来构建相机系统问题在于，在计算相机空间中的光线方向后，我将它乘以相机到世界的变换矩阵，我的相机似乎在错误的（相反的）方向上旋转，并且如果我在乘法之前反转变换矩阵则可以正常工作。 /> 这是代码（我使用glm库和右手坐标系）初步数据：

glm::vec3 origin_ = glm::vec3(0.f);// camera origin
cont glm::vec3 kDirection = glm::vec3(0.f, 0.f, -1.f);
cont glm::vec3 kUp = glm::vec3(0.f, 1.f, 0.f);
float aspect_ratio_ = (float)raster_height_ / raster_width_;

// bug !!! rotates in opposite direction  (camera is actually tilted down)
glm::mat4 camera_to_world_ = glm::lookAtRH(origin_, glm::vec3(0.f, 0.2f, -1.f), kUp);
// works !!! (camera is tilted up)
glm::mat4 camera_to_world_ = glm::inverse(glm::lookAtRH(origin_, glm::vec3(0.f, 0.2f, -1.f), kUp));

生成相机光线的功能

// Calculate ray as if camera is located at 0,0,0 and pointing into negative z direction
// Then transform ray direction to desired plase
// x,y - pixel coordinates of raster image
// calculate as if raster image (screen) is 1.0 unit away from origin (eye)
Ray Camera::GenRay(const uint32_t x, const uint32_t y) {
  glm::vec3 ray_direction = kDirection;
  // from raster space to NDC space
  glm::vec2 pixel_ndc((x + 0.5f) / raster_width_, (y + 0.5f) / raster_height_);
  // from NDC space to camera space
  float scale = tan(fov_ / 2.0f);
  ray_direction.x = (2.0f * pixel_ndc.x - 1.0f) * scale; // *aspect_ratio_;
  ray_direction.y = (1.0f - 2.0f * pixel_ndc.y) * scale * aspect_ratio_;
  // apply camera-to-world rotation matrix to direction
  ray_direction = camera_to_world_ * glm::vec4(ray_direction, 0.0f);

  return  Ray(origin_, ray_direction, Ray::Type::kPrimary);
}

我真的无法理解问题的根源，所以任何帮助我们的人都会感激不尽。

光线跟踪相机以错误的方向旋转

0 个答案: