1 files changed, 1 insertions, 1 deletions
diff --git a/doc/3D.md b/doc/3D.md
index 12c7b15..5bda566 100644
--- a/doc/3D.md
+++ b/doc/3D.md
@@ -72,7 +72,7 @@ struct BVHNode {
 
 ### Construction (CPU)
 
-Since the scene is small (< 100 objects) and dynamic, we will **rebuild** the BVH from scratch every frame. This avoids the complexity of refitting and balancing.
+Since the scene is small (< 100 objects) and dynamic, we will **rebuild** the BVH from scratch every frame on the CPU. This avoids the complexity of refitting and balancing. The BVH is purely a spatial acceleration structure and does not contain physics logic (velocity, mass, etc.), allowing it to be used for both rendering (GPU) and physics (CPU).
 
 **Algorithm: Recursive Midpoint Split**
 1.  **Calculate Centroids**: Compute the center of the AABB for all active objects.