diff --git a/lib/rbx_loader/src/union.rs b/lib/rbx_loader/src/union.rs
index a291920..bcd94ba 100644
--- a/lib/rbx_loader/src/union.rs
+++ b/lib/rbx_loader/src/union.rs
@@ -170,12 +170,12 @@ pub fn convert(
 		polygon_groups_normal_it.chain(physics_convex_meshes_it).collect::<Result<_,_>>()?
 	}else{
 		// generate a rectangular prism as default physics
-		let size=Planar64Vec3::new(size.to_array().map(|a|a.try_into().unwrap()))>>1;
+		let size=Planar64Vec3::new(size.to_array().map(|a|a.try_into().unwrap()));
 		let pos_list=CUBE_DEFAULT_VERTICES.map(|pos|
 			mb.acquire_pos_id(Planar64Vec3::new([
-				(pos.x*size.x).narrow_1().unwrap(),
-				(pos.y*size.y).narrow_1().unwrap(),
-				(pos.z*size.z).narrow_1().unwrap(),
+				((pos.x*size.x)>>2).narrow_1().unwrap(),
+				((pos.y*size.y)>>2).narrow_1().unwrap(),
+				((pos.z*size.z)>>2).narrow_1().unwrap(),
 			]))
 		);
 		let tex=mb.acquire_tex_id(glam::Vec2::ZERO);