code for assignment 3

[MicroTrace.git] / Sphere.cxx

diff --git a/Sphere.cxx b/Sphere.cxx
index 77d4320..6b8d943 100644 (file)
--- a/Sphere.cxx
+++ b/Sphere.cxx
@@ -1,7 +1,7 @@
 #include "Sphere.hxx"
 
 Sphere::Sphere(const Vec3f& center, float radius, Shader* shader)
-  : Primitive(shader),
+  : Primitive(shader), 
     m_center(center),
     m_radius(radius)
 {
@@ -20,39 +20,31 @@ Sphere::Intersect(Ray& ray)
 
   if( B*B-4*A*C < 0 )
     return false;
-
+  
   float root = sqrtf(B*B-4*A*C);
   float t = (-B-root)/(2.0f*A);
   if(t > ray.t())
     return false;
-
-  if( t < 1e-6 )
+      
+  if( t < Epsilon )
     {
       t = (-B+root)/(2.0f*A);
-      if( t < 1e-6 || t > ray.t())
+      if( t < Epsilon || t > ray.t())
        return false;
     }
+  
   ray.setT(t);
+  ray.setHit(this);
+  
   return true;
 }
 
 Vec3f
 Sphere::GetNormal(Ray& ray)
 {
-  // We don't want to modify the ray (probably this is not needed, but I am
-  // too lazy to think about it now ...)
-  Ray tempRay = ray;
+  Vec3f p = ray.origin()+ray.direction()*ray.t();
+  Vec3f N = (p-m_center);
+  N.normalize();
 
-  // Surface normal is the difference between intersection and center point
-  if(Intersect(tempRay)) {
-    // intersection point
-    Vec3f i = tempRay.origin() + tempRay.direction() * (tempRay.t() - Epsilon);
-    // normal
-    Vec3f n = (i - m_center);
-    n.normalize();
-    return n;
-  } else {
-    // no intersection with ray, so no surface normal
-    return Vec3f(0,0,0);
-  }
+  return N;
 }