simple anti-aliasing

diff --git a/MicroTrace.cxx b/MicroTrace.cxx
index 53c56ee..252ec18 100644 (file)
--- a/MicroTrace.cxx
+++ b/MicroTrace.cxx
@@ -17,7 +17,7 @@ void RenderFrameFlat(const std::string& fileName)
   /* Scene definition */
 
   Scene scene;
-  
+
   /* Flat shaders */
   FlatShader shd1(&scene, Vec3f(1,0,0)); // red surface
   FlatShader shd2(&scene, Vec3f(0,1,0)); // green surface
@@ -32,34 +32,39 @@ void RenderFrameFlat(const std::string& fileName)
   Sphere s3(Vec3f(3,0.8,-2), 2, &shd3);
   InfinitePlane p1(Vec3f(0,-1,0),Vec3f(0,1,0), &shd4);
 
-    
-  Triangle t1(Vec3f(-2,3,1),Vec3f(1,2,1),Vec3f(3,2.8,3), &shd5); 
-  
+
+  Triangle t1(Vec3f(-2,3,1),Vec3f(1,2,1),Vec3f(3,2.8,3), &shd5);
+
   /* add to scene */
   scene.Add(&s1);
   scene.Add(&s2);
   scene.Add(&s3);
   scene.Add(&p1);
   scene.Add(&t1);
-  
-  
+
+
   Image img(scene.camera()->resX(),scene.camera()->resY()); // image array
   Ray ray;                            // primary ray
-  
+
   for(int y = 0; y < scene.camera()->resY(); y++)
     {
-      for (int x = 0; x < scene.camera()->resX(); x++) 
-       {
-         
-         /* Initialize your ray here */
-         
-         scene.camera()->InitRay(x+0.5,y+0.5,ray); // initialize ray
-       
-         Vec3f col = scene.RayTrace(ray);
-         
-         img(x,y) = col; // store pixel color
-         //std::cerr << "Main: Image color = " << img(x,y) << std::endl;
-       }
+      for (int x = 0; x < scene.camera()->resX(); x++)
+      {
+
+        /* Initialize your ray here */
+        // shoot four rays for antialiasing
+        scene.camera()->InitRay(x+0.5,y+0.5, ray); // initialize ray
+        Vec3f col1 = scene.RayTrace(ray);
+        scene.camera()->InitRay(x-0.5,y+0.5, ray); // initialize ray
+        Vec3f col2 = scene.RayTrace(ray);
+        scene.camera()->InitRay(x-0.5,y-0.5, ray); // initialize ray
+        Vec3f col3 = scene.RayTrace(ray);
+        scene.camera()->InitRay(x-0.5,y-0.5, ray); // initialize ray
+        Vec3f col4 = scene.RayTrace(ray);
+
+        img(x,y) = (col1 + col2 + col3 + col4) / 4.0; // store pixel color
+        //std::cerr << "Main: Image color = " << img(x,y) << std::endl;
+      }
     }
   img.WritePPM(fileName); // write final image
 }
@@ -70,7 +75,7 @@ void RenderFrameEyeLight(const std::string& fileName)
   /* Scene definition */
 
   Scene scene;
-  
+
   /* Flat shaders */
   EyeLightShader shd1(&scene, Vec3f(1,0,0)); // red surface
   EyeLightShader shd2(&scene, Vec3f(0,1,0)); // green surface
@@ -85,33 +90,37 @@ void RenderFrameEyeLight(const std::string& fileName)
   Sphere s3(Vec3f(3,0.8,-2), 2, &shd3);
   InfinitePlane p1(Vec3f(0,-1,0),Vec3f(0,1,0), &shd4);
 
-    
-  Triangle t1(Vec3f(-2,3,1),Vec3f(1,2,1),Vec3f(3,2.8,3), &shd5); 
-  
+
+  Triangle t1(Vec3f(-2,3,1),Vec3f(1,2,1),Vec3f(3,2.8,3), &shd5);
+
   /* add to scene */
   scene.Add(&s1);
   scene.Add(&s2);
   scene.Add(&s3);
   scene.Add(&p1);
   scene.Add(&t1);
-  
+
   Image img(scene.camera()->resX(),scene.camera()->resY()); // image array
   Ray ray;                            // primary ray
-  
+
   for(int y = 0; y < scene.camera()->resY(); y++)
     {
-      for (int x = 0; x < scene.camera()->resX(); x++) 
-       {
-         
-         /* Initialize your ray here */
-         
-         scene.camera()->InitRay(x+0.5,y+0.5,ray); // initialize ray
-       
-         Vec3f col = scene.RayTrace(ray);
-         
-         img(x,y) = col; // store pixel color
-         //std::cerr << "Main: Image color = " << img(x,y) << std::endl;
-       }
+      for (int x = 0; x < scene.camera()->resX(); x++)
+      {
+
+        /* Initialize your ray here */
+        // shoot four rays for antialiasing
+        scene.camera()->InitRay(x+0.5,y+0.5, ray); // initialize ray
+        Vec3f col1 = scene.RayTrace(ray);
+        scene.camera()->InitRay(x-0.5,y+0.5, ray); // initialize ray
+        Vec3f col2 = scene.RayTrace(ray);
+        scene.camera()->InitRay(x-0.5,y-0.5, ray); // initialize ray
+        Vec3f col3 = scene.RayTrace(ray);
+        scene.camera()->InitRay(x-0.5,y-0.5, ray); // initialize ray
+        Vec3f col4 = scene.RayTrace(ray);
+
+        img(x,y) = (col1 + col2 + col3 + col4) / 4.0; // store pixel color
+      }
     }
   img.WritePPM(fileName); // write final image
 }
@@ -121,7 +130,7 @@ void RenderFrameReflectiveEyeLight(const std::string& fileName)
   /* Scene definition */
 
   Scene scene;
-  
+
   /* Flat shaders */
   ReflectiveEyeLightShader shd1(&scene, 1.0, Vec3f(1,0,0)); // red surface
   ReflectiveEyeLightShader shd2(&scene, 1.0, Vec3f(0.0,1.0,0.0)); // green surface
@@ -136,34 +145,38 @@ void RenderFrameReflectiveEyeLight(const std::string& fileName)
   Sphere s3(Vec3f(3,0.8,-2), 2, &shd3);
   InfinitePlane p1(Vec3f(0,-1,0),Vec3f(0,1,0), &shd4);
 
-    
-  Triangle t1(Vec3f(-2,3,1),Vec3f(1,2,1),Vec3f(3,2.8,3), &shd5); 
-  
+
+  Triangle t1(Vec3f(-2,3,1),Vec3f(1,2,1),Vec3f(3,2.8,3), &shd5);
+
   /* add to scene */
   scene.Add(&s1);
   scene.Add(&s2);
   scene.Add(&s3);
   scene.Add(&p1);
   scene.Add(&t1);
-  
-  
+
+
   Image img(scene.camera()->resX(),scene.camera()->resY()); // image array
   Ray ray;                            // primary ray
-  
+
   for(int y = 0; y < scene.camera()->resY(); y++)
     {
-      for (int x = 0; x < scene.camera()->resX(); x++) 
-       {
-         
-         /* Initialize your ray here */
-         
-         scene.camera()->InitRay(x+0.5,y+0.5,ray); // initialize ray
-       
-         Vec3f col = scene.RayTrace(ray);
-         
-         img(x,y) = col; // store pixel color
-         //std::cerr << "Main: Image color = " << img(x,y) << std::endl;
-       }
+      for (int x = 0; x < scene.camera()->resX(); x++)
+      {
+        /* Initialize your ray here */
+        // shoot four rays for antialiasing
+        scene.camera()->InitRay(x+0.5,y+0.5, ray); // initialize ray
+        Vec3f col1 = scene.RayTrace(ray);
+        scene.camera()->InitRay(x-0.5,y+0.5, ray); // initialize ray
+        Vec3f col2 = scene.RayTrace(ray);
+        scene.camera()->InitRay(x-0.5,y-0.5, ray); // initialize ray
+        Vec3f col3 = scene.RayTrace(ray);
+        scene.camera()->InitRay(x-0.5,y-0.5, ray); // initialize ray
+        Vec3f col4 = scene.RayTrace(ray);
+
+        img(x,y) = (col1 + col2 + col3 + col4) / 4.0; // store pixel color
+        //std::cerr << "Main: Image color = " << img(x,y) << std::endl;
+      }
     }
   img.WritePPM(fileName); // write final image
 }