diff --git a/ray-tracing-core/src/aabb.rs b/ray-tracing-core/src/aabb.rs
index c1a36cb..c5c626c 100644
--- a/ray-tracing-core/src/aabb.rs
+++ b/ray-tracing-core/src/aabb.rs
@@ -66,6 +66,10 @@ impl AABB {
             && pos.z <= self.max.z
     }
 
+    pub fn contains_aabb(self, aabb: Self) -> bool {
+        self.contains_point(aabb.min) && self.contains_point(aabb.max)
+    }
+
     pub fn size(self) -> Dir3 {
         Dir3::new(
             self.max.x - self.min.x,
@@ -92,7 +96,7 @@ impl AABB {
             Float::min(Float::max(t_min_z, t_max_z), max),
         );
 
-        if t_min < t_max {
+        if t_min <= t_max {
             Some(t_min)
         } else {
             None
diff --git a/ray-tracing-core/src/camera.rs b/ray-tracing-core/src/camera.rs
index b5751eb..59c5cc8 100644
--- a/ray-tracing-core/src/camera.rs
+++ b/ray-tracing-core/src/camera.rs
@@ -57,7 +57,8 @@ impl BasicCamera {
             pos: Pos3::new(tm.get(3, 0), tm.get(3, 1), tm.get(3, 2)),
             dir: Dir3::new(tm.get(2, 0), tm.get(2, 1), tm.get(2, 2)),
             h: l * Dir3::new(tm.get(0, 0), tm.get(0, 1), tm.get(0, 2)),
-            v: l * Dir3::new(tm.get(1, 0), tm.get(1, 1), tm.get(1, 2)),
+            v: l * ((height as Float) / (width as Float))
+                * Dir3::new(tm.get(1, 0), tm.get(1, 1), tm.get(1, 2)),
         }
     }
     pub fn from_look_at(
diff --git a/ray-tracing-pbrt-scene/example.pbrt b/ray-tracing-pbrt-scene/example.pbrt
index 87e1f7b..8b429c4 100644
--- a/ray-tracing-pbrt-scene/example.pbrt
+++ b/ray-tracing-pbrt-scene/example.pbrt
@@ -30,7 +30,8 @@ AttributeBegin
           "rgb tex1" [.1 .1 .1] "rgb tex2" [.8 .8 .8]
   Material "diffuse" "texture reflectance" "checks"
   Translate 0 0 -1
-  Shape "bilinearmesh"
+  Shape "trianglemesh"
+      "integer indices" [ 0 1 2 1 3 2 ]
       "point3 P" [ -20 -20 0   20 -20 0   -20 20 0   20 20 0 ]
       "point2 uv" [ 0 0   1 0    1 1   0 1 ]
 AttributeEnd
diff --git a/ray-tracing-pbrt-scene/src/bvh.rs b/ray-tracing-pbrt-scene/src/bvh.rs
index 2f5d0e4..d773491 100644
--- a/ray-tracing-pbrt-scene/src/bvh.rs
+++ b/ray-tracing-pbrt-scene/src/bvh.rs
@@ -64,7 +64,7 @@ impl<T: BvhData> Bvh<T> {
             unreachable!()
         };
 
-        if count <= min {
+        if count <= Index::max(1, min) {
             return;
         }
 
@@ -86,6 +86,9 @@ impl<T: BvhData> Bvh<T> {
         let left_aabb = data.get_aabb_range(start..(start + mid));
         let right_aabb = data.get_aabb_range((start + mid)..(start + count));
 
+        assert!(aabb.contains_aabb(left_aabb));
+        assert!(aabb.contains_aabb(right_aabb));
+
         let i = bvh.len() as Index;
         bvh[node] = Node::Inner {
             left: i,
diff --git a/ray-tracing-tev/src/main.rs b/ray-tracing-tev/src/main.rs
index 6c4981e..f2aaa6d 100644
--- a/ray-tracing-tev/src/main.rs
+++ b/ray-tracing-tev/src/main.rs
@@ -242,16 +242,18 @@ fn main() {
             Float::to_radians(fov),
         );
 
+        // dbg!(&c);
+
         // let c = BasicCamera::from_look_at(
         //     args.width,
         //     args.height,
-        //     Pos3::new(-0.3, 0.5, -0.5),
-        //     Pos3::new(0.0, 0.75, 0.0),
+        //     Pos3::new(3.0, 5.0, -5.0),
+        //     Pos3::new(0.0, 0.075, 0.0),
         //     Dir3::new(0.0, 1.0, 0.0),
         //     Float::to_radians(2.0 * 37.0),
         // );
 
-        // dbg!(c);
+        // dbg!(&c);
 
         let s = &pbrt.scene;