invole OBJ_Loader to load existed obj model, rasterize with multi-thread.

3rdparty/OBJ_Loader/CMakeLists.txt

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.14)
+project(OBJ_Loader)
+
+set(CMAKE_CXX_STANDARD 11)
+
+add_library(${PROJECT_NAME} INTERFACE)
+target_include_directories(${PROJECT_NAME} INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/include/)

CMakeLists.txt

@@ -1,5 +1,5 @@
-cmake_minimum_required(VERSION 3.9) 
-PROJECT(minus_renderer)
+cmake_minimum_required(VERSION 3.14) 
+project(minus_renderer)
 
 set(CMAKE_CXX_STANDARD 17)
 
@@ -12,4 +12,4 @@ add_subdirectory(${CMAKE_SOURCE_DIR}/src)
 # Third Party
 add_subdirectory(${CMAKE_SOURCE_DIR}/3rdparty/eigen)
 add_subdirectory(${CMAKE_SOURCE_DIR}/3rdparty/spdlog)
-
+add_subdirectory(${CMAKE_SOURCE_DIR}/3rdparty/OBJ_Loader)

src/CMakeLists.txt

@@ -1,8 +1,8 @@
-cmake_minimum_required(VERSION 3.9) 
+cmake_minimum_required(VERSION 3.14) 
 PROJECT(renderer)
 
 aux_source_directory(${CMAKE_CURRENT_SOURCE_DIR} CPP_FILES)
 
 add_executable(${CMAKE_PROJECT_NAME} ${CPP_FILES})
 target_include_directories(${CMAKE_PROJECT_NAME} PRIVATE ${OpenCV_INCLUDE_DIRS})
-target_link_libraries(${CMAKE_PROJECT_NAME} LINK_PUBLIC spdlog eigen ${OpenCV_LIBS})
+target_link_libraries(${CMAKE_PROJECT_NAME} LINK_PUBLIC OBJ_Loader spdlog eigen ${OpenCV_LIBS})

src/main.cc

@@ -9,36 +9,42 @@
 #include "camera.h"
 #include "common.h"
 #include "minus_renderer.h"
-#include "triangle.h"
 
 int main(int argc, char *argv[]) {
   spdlog::set_level(spdlog::level::trace);
 
-  const int resolution_width = 320;
-  const int resolution_height = 180;
-  const int far = -1000;
-  const int near = -10;
+  const std::string obj_path{argv[1]};
+
+  const int resolution_width = 640;
+  const int resolution_height = 320;
+  const int far = -100;
+  const int near = -1;
   const float fov = 120. / 180. * M_PI;
   const float aspect_ratio = static_cast<float>(resolution_width) /
                              static_cast<float>(resolution_height);
 
-  std::vector<Triangle> primitives{
-      {Point3d{10, 5, -20}, Point3d{30, 25, -20}, Point3d{55, 5, -20}}};
-
   cv::namedWindow("MinusRenderer", cv::WINDOW_AUTOSIZE);
   const auto start = std::chrono::steady_clock::now();
   Camera camera{Vector3d{0, 1, 0}};
-  MinusRenderer renderer{near, far, fov, aspect_ratio, std::move(primitives)};
+  MinusRenderer renderer{near, far, fov, aspect_ratio};
+  assert(renderer.load_mesh(obj_path));
+  TransformMatrix translate{
+      {1., 0., 0., 3.}, {0., 1., 0., 3.}, {0., 0., 1., -4.}, {0., 0., 0., 1.}};
+  renderer.model_transform(translate);
   do {
     const auto elapse = std::chrono::duration_cast<std::chrono::milliseconds>(
                             std::chrono::steady_clock::now() - start)
                             .count();
-    TransformMatrix m{
+    TransformMatrix move2origin{
+        {1, 0, 0, 0}, {0, 1, 0, -3}, {0, 0, 1, 4}, {0, 0, 0, 1}};
+    TransformMatrix rotation{
         Eigen::Transform<double, 3, Eigen::Affine>(
-            Eigen::AngleAxisd(0.03125 * M_PI, Eigen::Vector3d::UnitZ())
+            Eigen::AngleAxisd(0.0625 * M_PI, Eigen::Vector3d::UnitX())
                 .toRotationMatrix())
             .matrix()};
-    renderer.model_transform(m);
+    TransformMatrix move_back{
+        {1, 0, 0, 0}, {0, 1, 0, 3}, {0, 0, 1, -4}, {0, 0, 0, 1}};
+    renderer.model_transform(move_back * rotation * move2origin);
 
     camera.set_position(Point3d{0, 0, 0});
     camera.set_gaze(Vector3d{0, 0, -1});

src/minus_renderer.cc

@@ -3,16 +3,18 @@
 
 #include <cmath>
 
-#include "minus_renderer.h"
-#include "rasterizer.h"
+#include "OBJ_Loader.h"
 #include "spdlog/spdlog.h"
 
+#include "minus_renderer.h"
+#include "rasterizer.h"
+
 MinusRenderer::MinusRenderer(float near, float far, float fov,
-                             float aspect_ratio,
-                             std::vector<Triangle> &&primitives)
+                             float aspect_ratio)
     : near_(near), far_(far), fov_(fov), aspect_ratio_(aspect_ratio),
-      primitives_(primitives) {
-  spdlog::info("fov: {}, aspect ratio: {}", fov_, aspect_ratio_);
+      projection_matrix_(orthographic_tranform() * squish_tranform()) {
+  spdlog::info("near: {}, far: {}, fov: {}, aspect ratio: {}", near_, far_,
+               fov_, aspect_ratio_);
 }
 
 float MinusRenderer::calculate_height(const float fov, const float near) {
@@ -61,45 +63,84 @@ TransformMatrix MinusRenderer::view_port_transform(const float width,
                          {0, 0, 0, 1}};
 }
 
-void MinusRenderer::model_transform(const TransformMatrix &m) {
-  for (auto &t : primitives_) {
-    t.affine_transform(m);
+void MinusRenderer::model_transform(const TransformMatrix &mtx) {
+  for (auto &m : meshes_) {
+    for (auto &p : m) {
+      p.affine_transform(mtx);
+    }
   }
 }
 
-void MinusRenderer::view_transform(const TransformMatrix &m) {
-  for (auto &t : primitives_) {
-    t.affine_transform(m);
+void MinusRenderer::view_transform(const TransformMatrix &mtx) {
+  for (auto &m : meshes_) {
+    for (auto &p : m) {
+      p.affine_transform(mtx);
+    }
   }
 }
 
 cv::Mat MinusRenderer::render(const int resolution_width,
                               const int resolution_height) {
-  std::vector<Triangle> primitives = primitives_;
-  for (auto &t : primitives) {
-    t.projective_transform(squish_tranform());
-    t.affine_transform(orthographic_tranform());
-    t.affine_transform(
-        view_port_transform(resolution_width, resolution_height));
-  }
-
+  std::vector<Mesh> meshes = meshes_;
   Rasterizer rasterizer{resolution_width, resolution_height};
-  const auto &pixels = rasterizer.rasterize(primitives);
+  for (auto &primitives : meshes) {
+    for (int i = 0; i < primitives.size(); ++i) {
+      auto &t = primitives[i];
+      t.projective_transform(projection_matrix_);
+      t.affine_transform(
+          view_port_transform(resolution_width, resolution_height));
+    }
+    rasterizer.rasterize(primitives);
+  }
+  const auto &pixels = rasterizer.get_picture();
   assert(!pixels.empty());
   cv::Mat color_image(pixels.size(), (pixels[0]).size(), CV_8UC3);
+  cv::Mat depth_image(pixels.size(), (pixels[0]).size(), CV_8UC1);
 
   for (int i = 0; i < pixels.size(); ++i) {
     const auto &row = pixels[i];
     for (int j = 0; j < row.size(); ++j) {
       auto &pixel_color = color_image.at<cv::Vec3b>(pixels.size() - i - 1, j);
-      pixel_color =
-          cv::Vec3b{static_cast<unsigned char>(
-                        row[j].x() * std::numeric_limits<char>::max()),
-                    static_cast<unsigned char>(
-                        row[j].y() * std::numeric_limits<char>::max()),
-                    static_cast<unsigned char>(
-                        row[j].z() * std::numeric_limits<char>::max())};
+      pixel_color = cv::Vec3b{
+          static_cast<unsigned char>(row[j].x() *
+                                     std::numeric_limits<unsigned char>::max()),
+          static_cast<unsigned char>(row[j].y() *
+                                     std::numeric_limits<unsigned char>::max()),
+          static_cast<unsigned char>(
+              row[j].z() * std::numeric_limits<unsigned char>::max())};
+      auto &pixel_depth =
+          depth_image.at<unsigned char>(pixels.size() - i - 1, j);
+      if (std::isinf(std::fabs(row[j].w()))) {
+        pixel_depth = 0;
+      } else {
+        const float k =
+            static_cast<float>(std::numeric_limits<unsigned char>::max()) * 0.5;
+        const float b = k;
+        pixel_depth = static_cast<unsigned char>(k * row[j].w() + b);
+      }
     }
   }
-  return color_image;
+  return depth_image;
+}
+
+bool MinusRenderer::load_mesh(const std::string &file_path) {
+  objl::Loader loader{};
+  bool load_status = loader.LoadFile(file_path.c_str());
+  if (load_status) {
+    for (const auto &mesh : loader.LoadedMeshes) {
+      spdlog::info("Current mesh has {} vertices.", mesh.Vertices.size());
+      Mesh m{};
+      for (int i = 0; i < mesh.Vertices.size(); i += 3) {
+        const auto objl_v0 = mesh.Vertices[mesh.Indices[i]].Position;
+        Point3d v0(objl_v0.X, objl_v0.Y, objl_v0.Z);
+        const auto objl_v1 = mesh.Vertices[mesh.Indices[i + 1]].Position;
+        Point3d v1(objl_v1.X, objl_v1.Y, objl_v1.Z);
+        const auto objl_v2 = mesh.Vertices[mesh.Indices[i + 2]].Position;
+        Point3d v2(objl_v2.X, objl_v2.Y, objl_v2.Z);
+        m.push_back(Triangle(v0, v1, v2));
+      }
+      meshes_.push_back(m);
+    }
+  }
+  return load_status;
 }

src/minus_renderer.h

@@ -8,15 +8,20 @@
 
 class MinusRenderer {
 public:
-  MinusRenderer(float near, float far, float fov, float aspect_ratio,
-                std::vector<Triangle> &&primitives);
+  MinusRenderer(float near, float far, float fov, float aspect_ratio);
 
 public:
   cv::Mat render(const int resolution_width, const int resolution_height);
 
 public:
-  void model_transform(const TransformMatrix &m);
-  void view_transform(const TransformMatrix &m);
+  bool load_mesh(const std::string &file_path);
+
+public:
+  void model_transform(const TransformMatrix &mtx);
+  void view_transform(const TransformMatrix &mtx);
+
+private:
+  using Mesh = std::vector<Triangle>;
 
 private:
   static float calculate_height(const float fov, const float near);
@@ -34,5 +39,7 @@ private:
   float fov_; // In radian
   float aspect_ratio_;
 
-  std::vector<Triangle> primitives_;
+  TransformMatrix projection_matrix_;
+
+  std::vector<Mesh> meshes_;
 };

src/rasterizer.cc

@@ -2,9 +2,11 @@
 // Author: tianlei.richard@qq.com (tianlei.richard)
 
 #include <limits>
+#include <thread>
+
+#include "spdlog/spdlog.h"
 
 #include "rasterizer.h"
-#include "spdlog/spdlog.h"
 
 Rasterizer::Rasterizer(const int width, const int height)
     : width_(width), height_(height),
@@ -25,24 +27,54 @@ Rasterizer::rasterize(const std::vector<Triangle> &primitives) {
     const int y_min = std::min(std::max(0, aabb.y), height_);
     const int y_max = std::min(std::max(0, aabb.y + aabb.height), height_);
 
-    // spdlog::info("Range, ({},{},{},{})", x_min, x_max, y_min, y_max);
-    for (int i = y_min; i < y_max; ++i) {
-      for (int j = x_min; j < x_max; ++j) {
-        auto &property = pixels_[i][j];
-        const auto &[is_inside, z_screen] =
-            inside(Point2d{j + 0.5, i + 0.5}, t);
-        if (is_inside && z_screen > property[3]) {
-          property[0] = 0;
-          property[1] = 1;
-          property[2] = 0;
-          property[3] = z_screen;
+    auto partial_rasterize = [x_min, x_max, &t, this](const int start,
+                                                      const int end) {
+      for (int i = start; i < end; ++i) {
+        for (int j = x_min; j <= x_max; ++j) {
+          auto &property = (this->pixels_)[i][j];
+          const auto &[is_inside, z_screen] =
+              inside(Point2d{j + 0.5, i + 0.5}, t);
+          if (is_inside && z_screen > property[3]) {
+            property[0] = 0;
+            property[1] = 1;
+            property[2] = 0;
+            property[3] = z_screen;
+          }
         }
       }
+    };
+    const int thread_num = 6;
+    std::vector<std::thread> rasterize_threads;
+    for (int start = y_min, offset = (y_max - y_min) / thread_num,
+             remainer = (y_max - y_min) % thread_num;
+         start < y_max;) {
+      int end = start + offset;
+      if (remainer > 0) {
+        end += 1;
+        remainer -= 1;
+      }
+      rasterize_threads.push_back(std::thread(partial_rasterize, start, end));
+      start = end;
+    }
+    for (auto &t : rasterize_threads) {
+      t.join();
     }
   }
   return pixels_;
 }
 
+std::vector<std::vector<PixelProperty>> Rasterizer::get_picture() const {
+  return pixels_;
+}
+
+void Rasterizer::reset() {
+  pixels_ = std::vector<std::vector<PixelProperty>>(
+      height_,
+      std::vector<PixelProperty>(
+          width_,
+          PixelProperty{0., 0., 0., -std::numeric_limits<double>::infinity()}));
+}
+
 std::pair<bool, double> Rasterizer::inside(const Point2d &p_screen,
                                            const Triangle &t) {
   const auto points = t.get_points<3>();

src/rasterizer.h

@@ -8,12 +8,6 @@
 #include <vector>
 
 class Rasterizer {
-public:
-  typedef enum RasterizeMode {
-    Fill,
-    Line,
-  } RasterizeMode;
-
 public:
   Rasterizer(const int width, const int height);
 
@@ -21,6 +15,9 @@ public:
   std::vector<std::vector<PixelProperty>>
   rasterize(const std::vector<Triangle> &primitives);
 
+  std::vector<std::vector<PixelProperty>> get_picture() const;
+  void reset();
+
 private:
   static std::pair<bool, double> inside(const Point2d &p_screen,
                                         const Triangle &t);
@@ -29,6 +26,4 @@ private:
   int width_;
   int height_;
   std::vector<std::vector<PixelProperty>> pixels_;
-
-  RasterizeMode mode_ = RasterizeMode::Fill;
 };

src/triangle.cc

@@ -19,7 +19,7 @@ BBox Triangle::axis_align_bbox() const {
   const int y_min = std::min({points_[0].y(), points_[1].y(), points_[2].y()});
   const int x_max = std::max({points_[0].x(), points_[1].x(), points_[2].x()});
   const int y_max = std::max({points_[0].y(), points_[1].y(), points_[2].y()});
-  return BBox{x_min, y_min, (x_max - x_min), (y_max - y_min)};
+  return BBox{x_min, y_min, (x_max - x_min + 1), (y_max - y_min + 1)};
 }
 
 Vector3d Triangle::normal_vector() const {