not finished yet, but better than before

[MicroTrace.git] / Triangle.cxx

diff --git a/Triangle.cxx b/Triangle.cxx
index 456c6d8..498757e 100644 (file)
--- a/Triangle.cxx
+++ b/Triangle.cxx
@@ -7,8 +7,10 @@ Triangle::Triangle(const Vec3f& a,
   : Primitive(shader),
     m_a(a),
     m_b(b),
-    m_c(c)
+    m_c(c),
+    m_n( (b-a).cross(c-a) )
 {
+  m_n.normalize();
 }
 
 Triangle::~Triangle()
@@ -20,34 +22,35 @@ Triangle::Intersect(Ray& ray)
 {
   const Vec3f edge1 = m_b-m_a;
   const Vec3f edge2 = m_c-m_a;
-
+  
   const Vec3f pvec = ray.direction().cross(edge2);
-
+  
   const float det = edge1.dot(pvec);
   if (fabs(det) < Epsilon) return false;
-
+  
   const float inv_det = 1.0f / det;
-
+  
   const Vec3f tvec = ray.origin()-m_a;
   float lambda = tvec.dot( pvec );
   lambda *= inv_det;
-
-  if (lambda < 0.0f || lambda > 1.0f)
+    
+  if (lambda < 0.0f || lambda > 1.0f) 
     return false;
 
   const Vec3f qvec = tvec.cross(edge1);
   float mue = ray.direction().dot(qvec);
   mue *= inv_det;
-
-  if (mue < 0.0f || mue+lambda > 1.0f)
+  
+  if (mue < 0.0f || mue+lambda > 1.0f) 
     return false;
 
   float f = edge2.dot(qvec);
   f *= inv_det;
-  if (ray.t() <= f || f <  1e-4  )
+  if (ray.t() <= f || f < Epsilon ) 
     return false;
-
+  
   ray.setT(f);
+  ray.setHit(this);
 
   return true;
 }
@@ -55,8 +58,5 @@ Triangle::Intersect(Ray& ray)
 Vec3f
 Triangle::GetNormal(Ray& ray)
 {
-  // normal is cross product of spanning vectors
-  Vec3f n = (m_c - m_a) % (m_c - m_b);
-  n.normalize();
-  return n;
+  return m_n;
 }