diff --git a/src/accel/bvh.rs b/src/accel/bvh.rs
index 373209c..075df2f 100644
--- a/src/accel/bvh.rs
+++ b/src/accel/bvh.rs
@@ -18,7 +18,7 @@ pub struct BVH<'a> {
 }
 
 #[derive(Copy, Clone, Debug)]
-enum BVHNode<'a> {
+pub enum BVHNode<'a> {
     Internal {
         bounds: &'a [BBox],
         children: (&'a BVHNode<'a>, &'a BVHNode<'a>),
diff --git a/src/accel/bvh4.rs b/src/accel/bvh4.rs
index 88f5a64..c5311f7 100644
--- a/src/accel/bvh4.rs
+++ b/src/accel/bvh4.rs
@@ -29,7 +29,7 @@ pub struct BVH4<'a> {
 }
 
 #[derive(Copy, Clone, Debug)]
-enum BVH4Node<'a> {
+pub enum BVH4Node<'a> {
     Internal {
         bounds: &'a [BBox4],
         children: &'a [BVH4Node<'a>],
diff --git a/src/accel/mod.rs b/src/accel/mod.rs
index 3bde84d..34b8a41 100644
--- a/src/accel/mod.rs
+++ b/src/accel/mod.rs
@@ -8,8 +8,8 @@ mod objects_split;
 use math::{Vector, Point, Normal};
 use shading::surface_closure::SurfaceClosure;
 
-pub use self::bvh::BVH;
-pub use self::bvh4::BVH4;
+pub use self::bvh::{BVH, BVHNode};
+pub use self::bvh4::{BVH4, BVH4Node};
 pub use self::light_tree::LightTree;
 
 
diff --git a/src/main.rs b/src/main.rs
index 6db9bb1..87b9a01 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -58,6 +58,10 @@ use mem_arena::MemArena;
 use parse::{parse_scene, DataTree};
 use ray::{Ray, AccelRay};
 use renderer::LightPath;
+use bbox::BBox;
+use bbox4::BBox4;
+use accel::BVHNode;
+use accel::BVH4Node;
 use timer::Timer;
 
 
@@ -121,6 +125,10 @@ fn main() {
         println!("Ray size:       {} bytes", mem::size_of::<Ray>());
         println!("AccelRay size:  {} bytes", mem::size_of::<AccelRay>());
         println!("LightPath size: {} bytes", mem::size_of::<LightPath>());
+        println!("BBox size: {} bytes", mem::size_of::<BBox>());
+        println!("BBox4 size: {} bytes", mem::size_of::<BBox4>());
+        println!("BVHNode size: {} bytes", mem::size_of::<BVHNode>());
+        println!("BVH4Node size: {} bytes", mem::size_of::<BVH4Node>());
         return;
     }