diff --git a/lib/common/src/bvh.rs b/lib/common/src/bvh.rs
index 938cffe..11e4694 100644
--- a/lib/common/src/bvh.rs
+++ b/lib/common/src/bvh.rs
@@ -204,6 +204,8 @@ impl<L> BvhNode<L>{
 			match &node.content{
 				RecursiveContent::Leaf(leaf)=>if let Some(time)=f(leaf,ray){
 					let ins=TimedInstruction{time:time.into(),instruction:leaf};
+					// this lower bound can also be omitted
+					// but it causes type inference errors lol
 					if start_time.lt_ratio(ins.time)&&ins.time.lt_ratio(collector.time()){
 						collector.collect(Some(ins));
 					}
@@ -212,6 +214,8 @@ impl<L> BvhNode<L>{
 				RecursiveContent::Branch(children)=>for child in children{
 					// Am I an upcoming superstar?
 					if let Some(t)=intersect_aabb(ray,&child.aabb){
+						// we don't need to check the lower bound
+						// because child aabbs are guaranteed to be within the parent bounds.
 						if t<collector.time(){
 							nodes.insert(t,child);
 						}