diff --git a/main/Scene-load.cc b/main/Scene-load.cc
index ee34cd9..8fa78ca 100644
--- a/main/Scene-load.cc
+++ b/main/Scene-load.cc
@@ -532,6 +532,7 @@ refptr<Shape> Scene::processBool(refptr<Node> node)
     refptr<Material> material;
 
     bool restore_transform = processTransforms(node);
+    m_transforms.push(Transform());
 
     for (Node_Iterator it = node->getChildren().begin();
          it != node->getChildren().end();
@@ -559,11 +560,6 @@ refptr<Shape> Scene::processBool(refptr<Node> node)
         {
             processShapeDefinition(*it);
         }
-        else
-        {
-            cerr << "Error: unknown boolean object item" << endl;
-            exit(3);
-        }
     }
 
     if (shapes.size() < 2)
@@ -589,8 +585,9 @@ refptr<Shape> Scene::processBool(refptr<Node> node)
 
     if ( ! material.isNull() )
         shape->setMaterial(material);
-    shape->setTransform(m_transforms.top());
 
+    m_transforms.pop();
+    shape->setTransform(m_transforms.top());
     if (restore_transform)
         m_transforms.pop();
 
@@ -715,7 +712,7 @@ refptr<Shape> Scene::processShapeRef(refptr<Node> node)
             != m_shape_definitions.end())
     {
         refptr<Shape> shape = m_shape_definitions[node->getString()]->clone();
-        shape->setTransform(m_transforms.top());
+        shape->setTransform(m_transforms.top() * shape->getTransform());
         return shape;
     }
     cerr << "Error: no shape definition for '" << node->getString()
@@ -766,6 +763,8 @@ bool Scene::processTransforms(refptr<Node> node)
 
 void Scene::processShapeDefinition(refptr<Node> node)
 {
+    m_transforms.push(Transform());
     m_shape_definitions[node->getString()]
         = processShape(node->getChildren()[0]);
+    m_transforms.pop();
 }
diff --git a/shapes/Intersect.cc b/shapes/Intersect.cc
index b8adbf7..a4c421e 100644
--- a/shapes/Intersect.cc
+++ b/shapes/Intersect.cc
@@ -31,9 +31,10 @@ Intersect::Intersect(const vector< refptr<Shape> > & shapes)
 
 Shape::IntersectionList Intersect::intersect(refptr<Shape> _this, const Ray & ray)
 {
-    IntersectionList res1 = m_shape1->intersect(m_shape1, ray);
-    IntersectionList res2 = m_shape2->intersect(m_shape2, ray);
-    BoolIntersectionList merged(res1, res2, ray.getOrigin());
+    Ray ray_inv = m_inverse.transform_ray(ray);
+    IntersectionList res1 = m_shape1->intersect(m_shape1, ray_inv);
+    IntersectionList res2 = m_shape2->intersect(m_shape2, ray_inv);
+    BoolIntersectionList merged(res1, res2, ray_inv.getOrigin());
 
     IntersectionList res;
     bool in1 = false, in2 = false;
@@ -45,7 +46,7 @@ Shape::IntersectionList Intersect::intersect(refptr<Shape> _this, const Ray & ra
          i++)
     {
         Vector normal = merged[i].intersection.normal;
-        double dot = - (ray.getDirection() % normal);
+        double dot = - (ray_inv.getDirection() % normal);
         bool back = dot < 0.0;
         bool left = merged[i].left;
         if (back)
@@ -65,7 +66,7 @@ Shape::IntersectionList Intersect::intersect(refptr<Shape> _this, const Ray & ra
     for (int i = 0, sz = merged.size(); i < sz; i++)
     {
         Vector normal = merged[i].intersection.normal;
-        double dot = - (ray.getDirection() % normal);
+        double dot = - (ray_inv.getDirection() % normal);
         bool front = dot > 0.0;
         bool left = merged[i].left;
         if (front)
@@ -78,7 +79,7 @@ Shape::IntersectionList Intersect::intersect(refptr<Shape> _this, const Ray & ra
             {
                 /* we found an intersection point with the boolean object */
                 in_bool = true;
-                res.add( merged[i].intersection );
+                res.add( merged[i].intersection.transform(m_transform) );
             }
         }
         else
@@ -86,7 +87,7 @@ Shape::IntersectionList Intersect::intersect(refptr<Shape> _this, const Ray & ra
             if (in_bool && in1 && in2)
             {
                 /* we found an intersection point with the boolean object */
-                res.add( merged[i].intersection );
+                res.add( merged[i].intersection.transform(m_transform) );
             }
             if (left)
                 in1 = false;
diff --git a/shapes/Shape.h b/shapes/Shape.h
index b5ad9c6..5e78d41 100644
--- a/shapes/Shape.h
+++ b/shapes/Shape.h
@@ -29,6 +29,12 @@ class Shape
                 refptr<Shape> shape;
                 Vector position;
                 Vector normal;
+                Intersection transform(Transform & t)
+                {
+                    return Intersection(shape,
+                            t.transform_point(position),
+                            t.transform_normal(normal));
+                }
         };
         class BoolIntersection
         {
@@ -103,10 +109,10 @@ class Shape
                                            const Ray & ray) = 0;
         virtual refptr<Shape> clone() = 0;
 
-        void setTransform(Transform & t)
+        void setTransform(const Transform & t)
         {
             m_transform = t;
-            m_inverse = t.getInverse();
+            m_inverse = m_transform.getInverse();
         }
         Transform & getTransform() { return m_transform; }
 
diff --git a/shapes/Subtract.cc b/shapes/Subtract.cc
index a61f6de..a2f2d94 100644
--- a/shapes/Subtract.cc
+++ b/shapes/Subtract.cc
@@ -31,9 +31,10 @@ Subtract::Subtract(const vector< refptr<Shape> > & shapes)
 
 Shape::IntersectionList Subtract::intersect(refptr<Shape> _this, const Ray & ray)
 {
-    IntersectionList res1 = m_shape1->intersect(m_shape1, ray);
-    IntersectionList res2 = m_shape2->intersect(m_shape2, ray);
-    BoolIntersectionList merged(res1, res2, ray.getOrigin());
+    Ray ray_inv = m_inverse.transform_ray(ray);
+    IntersectionList res1 = m_shape1->intersect(m_shape1, ray_inv);
+    IntersectionList res2 = m_shape2->intersect(m_shape2, ray_inv);
+    BoolIntersectionList merged(res1, res2, ray_inv.getOrigin());
 
     IntersectionList res;
     bool in1 = false, in2 = false;
@@ -45,7 +46,7 @@ Shape::IntersectionList Subtract::intersect(refptr<Shape> _this, const Ray & ray
          i++)
     {
         Vector normal = merged[i].intersection.normal;
-        double dot = - (ray.getDirection() % normal);
+        double dot = - (ray_inv.getDirection() % normal);
         bool back = dot < 0.0;
         bool left = merged[i].left;
         if (back)
@@ -65,7 +66,7 @@ Shape::IntersectionList Subtract::intersect(refptr<Shape> _this, const Ray & ray
     for (int i = 0, sz = merged.size(); i < sz; i++)
     {
         Vector normal = merged[i].intersection.normal;
-        double dot = - (ray.getDirection() % normal);
+        double dot = - (ray_inv.getDirection() % normal);
         bool front = dot > 0.0;
         bool left = merged[i].left;
         if (left)
@@ -81,7 +82,7 @@ Shape::IntersectionList Subtract::intersect(refptr<Shape> _this, const Ray & ray
             Intersection i = bi.intersection;
             if ( ! left )   /* if this point came from object B (A - B) */
                 i.normal = - i.normal;
-            res.add(i);
+            res.add(i.transform(m_transform));
         }
         else if (in_bool && !(in1 && !in2))
         {
@@ -91,7 +92,7 @@ Shape::IntersectionList Subtract::intersect(refptr<Shape> _this, const Ray & ray
             Intersection i = bi.intersection;
             if ( ! left )   /* if this point came from object B (A - B) */
                 i.normal = - i.normal;
-            res.add(i);
+            res.add(i.transform(m_transform));
             in_bool = false;
         }
     }
diff --git a/shapes/Union.cc b/shapes/Union.cc
index 5000b33..e8d81d8 100644
--- a/shapes/Union.cc
+++ b/shapes/Union.cc
@@ -32,9 +32,10 @@ Union::Union(const vector< refptr<Shape> > & shapes)
 
 Shape::IntersectionList Union::intersect(refptr<Shape> _this, const Ray & ray)
 {
-    IntersectionList res1 = m_shape1->intersect(m_shape1, ray);
-    IntersectionList res2 = m_shape2->intersect(m_shape2, ray);
-    BoolIntersectionList merged(res1, res2, ray.getOrigin());
+    Ray ray_inv = m_inverse.transform_ray(ray);
+    IntersectionList res1 = m_shape1->intersect(m_shape1, ray_inv);
+    IntersectionList res2 = m_shape2->intersect(m_shape2, ray_inv);
+    BoolIntersectionList merged(res1, res2, ray_inv.getOrigin());
 
     IntersectionList res;
     bool in1 = false, in2 = false;
@@ -46,7 +47,7 @@ Shape::IntersectionList Union::intersect(refptr<Shape> _this, const Ray & ray)
          i++)
     {
         Vector normal = merged[i].intersection.normal;
-        double dot = - (ray.getDirection() % normal);
+        double dot = - (ray_inv.getDirection() % normal);
         bool back = dot < 0.0;
         bool left = merged[i].left;
         if (back)
@@ -66,7 +67,7 @@ Shape::IntersectionList Union::intersect(refptr<Shape> _this, const Ray & ray)
     for (int i = 0, sz = merged.size(); i < sz; i++)
     {
         Vector normal = merged[i].intersection.normal;
-        double dot = - (ray.getDirection() % normal);
+        double dot = - (ray_inv.getDirection() % normal);
         bool front = dot > 0.0;
         bool left = merged[i].left;
         if (front)
@@ -79,7 +80,7 @@ Shape::IntersectionList Union::intersect(refptr<Shape> _this, const Ray & ray)
             {
                 /* we found an intersection point with the boolean object */
                 in_bool = true;
-                res.add( merged[i].intersection );
+                res.add( merged[i].intersection.transform(m_transform) );
             }
         }
         else
@@ -91,7 +92,7 @@ Shape::IntersectionList Union::intersect(refptr<Shape> _this, const Ray & ray)
             if (in_bool && !(in1 || in2))
             {
                 /* we found an intersection point with the boolean object */
-                res.add( merged[i].intersection );
+                res.add( merged[i].intersection.transform(m_transform) );
                 in_bool = false;
             }
         }
diff --git a/util/Transform.cc b/util/Transform.cc
index c7853bc..ea76787 100644
--- a/util/Transform.cc
+++ b/util/Transform.cc
@@ -104,3 +104,10 @@ Ray Transform::transform_ray(const Ray & r)
     Ray res(newPosition, newDirection);
     return res;
 }
+
+Transform Transform::operator*(const Transform & other) const
+{
+    Transform t;
+    t.m_matrix = m_matrix * other.m_matrix;
+    return t;
+}
diff --git a/util/Transform.h b/util/Transform.h
index eeaef69..da9654f 100644
--- a/util/Transform.h
+++ b/util/Transform.h
@@ -36,6 +36,7 @@ class Transform
         Vector transform_direction(const Vector & v);
         Vector transform_normal(const Vector & v);
         Ray transform_ray(const Ray & r);
+        Transform operator*(const Transform & other) const;
 
     protected:
         Matrix m_matrix;