complete assignment2

Author: root

.project_alt.json

@@ -0,0 +1,4 @@
+{
+  "*.cpp": {"alternate": "{}.hpp"},
+  "*.hpp": {"alternate": "{}.cpp"}
+}

Assignment1/Assignment1/main.cpp

@@ -29,7 +29,7 @@ Eigen::Matrix4f get_model_matrix(float rotation_angle)
     Eigen::Matrix4f rotation;
     float angle = rotation_angle * M_PI / 180;
 
-    rotation << cos(angle), -sin(angle), 0, 0, sin(angle), cos(angle),0, 0,
+    rotation << cosf(angle), -sinf(angle), 0, 0, sinf(angle), cosf(angle),0, 0,
         0, 0, 1, 0, 0, 0, 0, 1;
     model = rotation * model;
 
@@ -62,59 +62,33 @@ Eigen::Matrix4f get_projection_matrix(float eye_fov, float aspect_ratio,
     return projection;
 }
 
-//利用罗德里格斯旋转公式得到绕过原点任意直线的旋转矩阵
-Eigen::Matrix4f get_rotation(Vector3f axis, float angle) {
-    Eigen::Matrix3f I = Eigen::Matrix3f::Identity();
-    float ra = angle * M_PI / 180;
-    Eigen::Matrix3f R, N;
-
-    N << 0, -axis.z(), axis.y(),
-         axis.z(), 0, -axis.x(),
-         -axis.y(), axis.x(), 0;
+//利用罗德里格斯公式得到绕任意过原点的轴的旋转矩阵
+Eigen:Matrix4f get_rotation(Vector3f axis, float angle) {
+    Eigen::Matrix4f identity = Eigen::Matrix4f::Identity();
 
-    R << cosf(ra) * I + (1 - cosf(ra)) * axis * axis.transpose() + sinf(ra) * N;
-
-    Eigen::Matrix4f R_homo;
+    float ra = angle * M_PI / 180;
+    Eigen::Matrix3f n;
+    n << 0, -axis.z, axis.y, axis.z, 0, -axis.x, -axis.y, axis.x, 0;
 
-    /*将旋转矩阵扩展成齐次坐标形式*/
-    for(int i = 0; i < 4; i++){
-        for(int j = 0;j < 4; j++){
-            if(i == 3 || j == 3){
-                if(i!=j)
-                    R_homo(i, j)=0;
-                else
-                    R_homo(i, j)=1;
-            }
-            else{
-                R_homo(i, j)=R(i, j);
-            }
-        }
-    }
-    return R_homo;
+    return toMatrix4f(cosf(ra) * identity, (1 - cosf(ra)) * axis * axis.transpose, sinf(ra) * n)
 }
 
-
 int main(int argc, const char** argv)
 {
     float angle = 0;
     bool command_line = false;
-    bool rodrigue_rotation = false;
     std::string filename = "output.png";
-    
-    Eigen::Matrix4f rodrigueM;
 
-    if (argc >= 3) {
-        if (std::string(argv[1]) == "-r") {
+    if (argc >= 2) {
+        if (argc[2] == "-r" && argc >= 3) {
             command_line = true;
             angle = std::stof(argv[2]); // -r by default
             if (argc == 4) {
                 filename = std::string(argv[3]);
             }
-        } else if (std::string(argv[1]) == "-c" && argc == 6) {
-            angle = std::stof(argv[5]);
-            rodrigue_rotation = true;
-            Eigen::Vector3f axis(std::stof(argv[2]), std::stof(argv[3]), std::stof(argv[4]));
-            rodrigueM = get_rotation(axis, angle);
+        } else if(argc[2] == "-c" && argc = 5) {
+
+
         }
     }
 
@@ -153,12 +127,7 @@ int main(int argc, const char** argv)
 
         r.set_model(get_model_matrix(angle));
         r.set_view(get_view_matrix(eye_pos));
-
-        if (rodrigue_rotation) {
-           r.set_projection(get_projection_matrix(45, 1, 0.1, 50) * rodrigueM);
-        } else {
-           r.set_projection(get_projection_matrix(45, 1, 0.1, 50));
-        }
+        r.set_projection(get_projection_matrix(45, 1, 0.1, 50));
 
         r.draw(pos_id, ind_id, rst::Primitive::Triangle);
 

Assignment2/õ+úþáüµíåµ×Â/CMakeLists.txt Assignment2/Assignment2/CMakeLists.txt

@@ -25,14 +25,35 @@ Eigen::Matrix4f get_view_matrix(Eigen::Vector3f eye_pos)
 Eigen::Matrix4f get_model_matrix(float rotation_angle)
 {
     Eigen::Matrix4f model = Eigen::Matrix4f::Identity();
+
+    Eigen::Matrix4f rotation;
+    float angle = rotation_angle * M_PI / 180;
+
+    rotation << cos(angle), -sin(angle), 0, 0, sin(angle), cos(angle),0, 0,
+        0, 0, 1, 0, 0, 0, 0, 1;
+    model = rotation * model;
+
     return model;
 }
 
-Eigen::Matrix4f get_projection_matrix(float eye_fov, float aspect_ratio, float zNear, float zFar)
+Eigen::Matrix4f get_projection_matrix(float eye_fov, float aspect_ratio,
+                                      float zNear, float zFar)
 {
-    // TODO: Copy-paste your implementation from the previous assignment.
-    Eigen::Matrix4f projection;
+    Eigen::Matrix4f projection = Eigen::Matrix4f::Identity();
+
+    float fov_angle = eye_fov * M_PI / 180;
+
+    float n = -zNear;
+    float t = tan(fov_angle / 2) * zNear; 
+    float b = -t;
+    float r = t * aspect_ratio;
+    float l = -r;
+    float f = -zFar;
 
+    projection << 2 * n /(r - l), 0, (l + r)/(l - r) , 0,
+        0, 2 * n /(t-b), (b + r)/(b - t), 0,
+        0, 0, (f + n)/(n - f), 2 * f * n / (f-n),
+        0, 0 ,1, 0;    
     return projection;
 }
 

Assignment2/õ+úþáüµíåµ×Â/Triangle.cpp Assignment2/Assignment2/Triangle.cpp

@@ -9,7 +9,6 @@
 #include <opencv2/opencv.hpp>
 #include <math.h>
 
-
 rst::pos_buf_id rst::rasterizer::load_positions(const std::vector<Eigen::Vector3f> &positions)
 {
     auto id = get_next_id();
@@ -43,6 +42,24 @@ auto to_vec4(const Eigen::Vector3f& v3, float w = 1.0f)
 static bool insideTriangle(int x, int y, const Vector3f* _v)
 {   
     // TODO : Implement this function to check if the point (x, y) is inside the triangle represented by _v[0], _v[1], _v[2]
+    Eigen::Vector2f AB, BC, CA, AP, BP, CP, p;
+    float a, b, c;
+    p << x, y;
+    AB = _v[1].head(2) - _v[0].head(2);
+    AP = p -_v[0].head(2);
+    BC = _v[2].head(2) - _v[1].head(2);
+    BP = p -_v[1].head(2);
+    CA = _v[0].head(2) - _v[2].head(2);
+    CP = p -_v[2].head(2);
+    a = AB[0] * AP[1] - AB[1] * AP[0];
+    b = BC[0] * BP[1] - BC[1] * BP[0];
+    c = CA[0] * CP[1] - CA[1] * CP[0];
+    if (a > 0 && b > 0 && c > 0) {
+        return true;
+    } else if (a < 0 && b < 0 && c < 0) {
+        return true;
+    }
+    return false;
 }
 
 static std::tuple<float, float, float> computeBarycentric2D(float x, float y, const Vector3f* v)
@@ -108,14 +125,31 @@ void rst::rasterizer::rasterize_triangle(const Triangle& t) {
 
     // TODO : Find out the bounding box of current triangle.
     // iterate through the pixel and find if the current pixel is inside the triangle
-
     // If so, use the following code to get the interpolated z value.
-    //auto[alpha, beta, gamma] = computeBarycentric2D(x, y, t.v);
-    //float w_reciprocal = 1.0/(alpha / v[0].w() + beta / v[1].w() + gamma / v[2].w());
-    //float z_interpolated = alpha * v[0].z() / v[0].w() + beta * v[1].z() / v[1].w() + gamma * v[2].z() / v[2].w();
-    //z_interpolated *= w_reciprocal;
-
     // TODO : set the current pixel (use the set_pixel function) to the color of the triangle (use getColor function) if it should be painted.
+    int minX  = std::min(std::min(v[0].x(), v[1].x()), v[2].x());
+    int minY  = std::min(std::min(v[0].y(), v[1].y()), v[2].y());
+    int maxX  = std::max(std::max(v[0].x(), v[1].x()), v[2].x());
+    int maxY  = std::max(std::max(v[0].y(), v[1].y()), v[2].y());
+
+    for (int x = minX; x < maxX; x++) {
+        for (int y = minY; y < maxY; y++) {
+            if (insideTriangle(x + 0.5, y + 0.5, t.v)) {
+                auto[alpha, beta, gamma] = computeBarycentric2D(x + 0.5, y + 0.5, t.v);
+                float w_reciprocal = 1.0/(alpha / v[0].w() + beta / v[1].w() + gamma / v[2].w());
+                float z_interpolated = alpha * v[0].z() / v[0].w() + beta * v[1].z() / v[1].w() + gamma * v[2].z() / v[2].w();
+                z_interpolated *= w_reciprocal;
+
+                int cur_index = get_index(x, y);
+                if (z_interpolated < depth_buf[cur_index]) {
+                    depth_buf[cur_index] = z_interpolated;
+                    Vector3f vertex;
+                    vertex << x, y, z_interpolated;
+                    set_pixel(vertex, t.getColor());
+                }    
+            }            
+        }
+    }
 }
 
 void rst::rasterizer::set_model(const Eigen::Matrix4f& m)
@@ -164,4 +198,4 @@ void rst::rasterizer::set_pixel(const Eigen::Vector3f& point, const Eigen::Vecto
 
 }
 
-// clang-format on
+// clang-format on