diff --git a/app-proto/inversive-display/src/main.rs b/app-proto/inversive-display/src/main.rs
index 1937e2b..d2bc742 100644
--- a/app-proto/inversive-display/src/main.rs
+++ b/app-proto/inversive-display/src/main.rs
@@ -166,10 +166,9 @@ fn main() {
                     // vector with respect to the coordinates of the impact
                     // point. i calculated it in my head and decided that
                     // the result looked good enough for now
-                    vec3 normal_front = normalize(-v.sp + 2.*v.lt.s*pt);
+                    vec3 normal = normalize(-v.sp + 2.*v.lt.s*pt);
                     
-                    vec3 color;
-                    float incidence = dot(normal_front, light_dir);
+                    float incidence = dot(normal, light_dir);
                     float illum = mix(0.4, 1.0, max(incidence, 0.0));
                     return taggedFrag(vec4(illum * base_color, opacity), -pt.z);
                 }