This page is designed to give you a sense of what your images should look like.

• To check that your rays are being cast in the right direction you want to modify your ray-casting code to write out a new .ray file with some of the cast rays displayed. You can do this by modifying your RayTrace(const char* fileName, int width, int height, int rLimit, float cLimit) routine to look something like:

  int i,j;
  Ray ray,r;
  FILE* fp;
  ...

  fp=fopen("temp.ray","w");
  assert(fp);
  scene.write(fp);
  for(i=0;i<width;i++){
       for(j=0;j<height;j++){
           ray=Ray(...);
           ...
           if(i%20 ==0 & j%20==0){
               Line(Ray(ray.p,ray(5.0)),scene.getMaterial(0)).write(0,fp);
           }
           ...
       }
  }
  fclose(fp);
  ...
  

  Run

  tracer -src RayFiles/simple_sphere.ray -dst out.bmp.

  Now you can call

  viewer -src temp.ray

  and after moving around a bit you would get an image that looks like this:
  

  

  You should make sure that all of your rays are coming out of a single point and that they are all heading towards the sphere.

• If you have written your Sphere::intersect(Ray ray, IntersectionInfo& iInfo) properly then running

  tracer -src RayFiles/simple_sphere.ray -dst out.bmp

  should give you a .bmp file that looks like this:
  

  

• If you have written your Triangle::intersect(Ray ray, IntersectionInfo& iInfo) properly then running

  tracer -src RayFiles/simple_triangle.ray -dst out.bmp

  should give you a .bmp file that looks like this:
  

  

• If you have written your Group::intersect(Ray ray, IntersectionInfo& iInfo) properly then running

  tracer -src RayFiles/triangle_sphere.ray -dst out.bmp

  should give you a .bmp file that looks like this:
  

  

• If you have modified the GetColor(Scene scene, IntersectionInfo iInfo, int rDepth, int maxDepth, float  cLimit) to take into account ambient and emissive light then running

  tracer -src RayFiles/triangle_sphere.ray -dst out.bmp

  should give you a .bmp file that looks like this:
  

  

• If you have implemented the getDiffuse(Point3D cameraPosition, IntersectionInfo iInfo) for SpotLight, PointLight, and DirectionalLight and added the modifications to GetColor(Scene scene, IntersectionInfo iInfo, int rDepth, int maxDepth, float  cLimit) then running

  tracer -src RayFiles/triangle_sphere_2.ray -dst out.bmp

  should give you a .bmp file that looks like this:
  

  

• If you have implemented the getSpecular(Point3D cameraPosition, IntersectionInfo iInfo) for SpotLight, PointLight, and DirectionalLight and added the modifications to GetColor(Scene scene, IntersectionInfo iInfo, int rDepth, int maxDepth, float  cLimit) then running

  tracer -src RayFiles/triangle_sphere_2.ray -dst out.bmp

  should give you a .bmp file that looks like this:
  

  

• If you have implemented the isInShadow( IntersectionInfo iInfo, Shape* shape) for SpotLight, PointLight, and DirectionalLight and added the modifications to GetColor(Scene scene, IntersectionInfo iInfo, int rDepth, int maxDepth, float  cLimit) then running

  tracer -src RayFiles/triangle_sphere_2.ray -dst out.bmp

  should give you a .bmp file that looks like this:
  

  

• If you have modified Group::intersect(Ray ray, IntersectionInfo& iInfo) to take into account local transformations, then running

  tracer -src RayFiles/triangle_sphere_3.ray -dst out.bmp

  should give you a .bmp file that looks like this:
  

  

  (This is somewhat tricky because one of the local transformations is not distance-preserving, so you have to make sure that your normals are going in the right direction and that vectors you expect to be unit vectors are actually unit vectors.)