diff --git a/app-proto/inversive-display/src/main.rs b/app-proto/inversive-display/src/main.rs
index e3e7135..b120f1a 100644
--- a/app-proto/inversive-display/src/main.rs
+++ b/app-proto/inversive-display/src/main.rs
@@ -75,6 +75,7 @@ fn main() {
         let radius_x = create_signal(1.0);
         let radius_y = create_signal(1.0);
         let opacity = create_signal(0.5);
+        let highlight = create_signal(0.2);
         let layer_threshold = create_signal(0.0);
         let display = create_node_ref();
         
@@ -120,6 +121,7 @@ fn main() {
                 uniform vec2 ctrl;
                 uniform vec2 radius;
                 uniform float opacity;
+                uniform float highlight;
                 uniform int layer_threshold;
                 
                 // light and camera
@@ -273,14 +275,14 @@ fn main() {
                             abs(dot(frag1.normal, disp)),
                             abs(dot(frag0.normal, disp))
                         ) / ixn_sin;
-                        float ixn_highlight = 1. - smoothstep(2./3.*ixn_threshold, 1.5*ixn_threshold, ixn_dist);
+                        float ixn_highlight = 0.5 * highlight * (1. - smoothstep(2./3.*ixn_threshold, 1.5*ixn_threshold, ixn_dist));
                         frags_by_depth[i].color = mix(frags_by_depth[i].color, vec4(1.), ixn_highlight);
                         frags_by_depth[i-1].color = mix(frags_by_depth[i-1].color, vec4(1.), ixn_highlight);
                         
                         // cusps
                         float cusp_cos = abs(dot(dir, frag0.normal));
                         float cusp_threshold = 2.*sqrt(ixn_threshold * v[frag0.id].lt.s);
-                        float cusp_highlight = 1. - smoothstep(2./3.*cusp_threshold, 1.5*cusp_threshold, cusp_cos);
+                        float cusp_highlight = highlight * (1. - smoothstep(2./3.*cusp_threshold, 1.5*cusp_threshold, cusp_cos));
                         frags_by_depth[i].color = mix(frags_by_depth[i].color, vec4(1.), cusp_highlight);
                     }
                     
@@ -319,6 +321,7 @@ fn main() {
             let ctrl_loc = ctx.get_uniform_location(&program, "ctrl");
             let radius_loc = ctx.get_uniform_location(&program, "radius");
             let opacity_loc = ctx.get_uniform_location(&program, "opacity");
+            let highlight_loc = ctx.get_uniform_location(&program, "highlight");
             let layer_threshold_loc = ctx.get_uniform_location(&program, "layer_threshold");
             
             // create a vertex array and bind it to the graphics context
@@ -351,6 +354,7 @@ fn main() {
                 ctx.uniform2f(ctrl_loc.as_ref(), ctrl_x.get() as f32, ctrl_y.get() as f32);
                 ctx.uniform2f(radius_loc.as_ref(), radius_x.get() as f32, radius_y.get() as f32);
                 ctx.uniform1f(opacity_loc.as_ref(), opacity.get() as f32);
+                ctx.uniform1f(highlight_loc.as_ref(), highlight.get() as f32);
                 ctx.uniform1i(layer_threshold_loc.as_ref(), layer_threshold.get() as i32);
                 
                 // clear the screen and draw the scene
@@ -397,6 +401,12 @@ fn main() {
                     step=0.001,
                     bind:valueAsNumber=opacity
                 )
+                input(
+                    type="range",
+                    max=1.0,
+                    step=0.001,
+                    bind:valueAsNumber=highlight
+                )
                 input(
                     type="range",
                     max=3.0,