diff --git a/Assets/backbox.hlsl b/Assets/backbox.hlsl
index cf59f51..729f576 100644
--- a/Assets/backbox.hlsl
+++ b/Assets/backbox.hlsl
@@ -24,7 +24,8 @@ psIn vs(vsIn input, uint id : SV_InstanceID) {
 	float3 world = mul(float4(input.pos.xyz, 1), sk_inst[id].world).xyz;
 	o.pos        = mul(float4(world,         1), sk_viewproj[o.view_id]);
 
-	float3 normal = normalize(mul(input.norm, (float3x3)sk_inst[id].world));
+	// flip input normals to treat backfaces like normal
+	float3 normal = normalize(mul(-input.norm, (float3x3)sk_inst[id].world));
 
 
 	float3 norm_shade = float3(0.5) + (normal * 0.5);
@@ -34,7 +35,7 @@ psIn vs(vsIn input, uint id : SV_InstanceID) {
 
   // rim lighting
   float rim = 1.0 - saturate(dot(normalize(view_dir), normal));
-  o.color = float4(norm_shade * rim * rim * 0.2, 1);
+  o.color = float4(norm_shade * rim * rim * 0.0666, 1);
 
 	return o;
 }