diff --git a/src/render.rs b/src/render.rs
index 3dcaca3..72e3fb0 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -9,20 +9,6 @@ use std::fs::File;
 use std::path::PathBuf;
 use y4m;
 
-// fn clamp(v: f32, range: f32) -> f32 {
-//     v.min(range).max(-range)
-// }
-
-// fn curl(x: f64, y: f64) -> f64 {
-//     let c = x * y;
-//     if c >= 0.0 {
-//         c.sqrt()
-//     } else {
-//         -(-c).sqrt()
-//     }
-// }
-//
-
 /// Accept a value from (-\inf, \inf) and return a value in (-1, 1).
 /// If the input is equal to `typical`, it will be mapped to 0.5.
 /// If the input is equal to -`typical`, it will be mapped to -0.5.
@@ -77,16 +63,8 @@ impl SimStateRenderExt for SimState {
         for y in 0..h {
             for x in 0..w {
                 let cell = self.get(x as usize, y as usize);
-                //let r = norm_color(cell.bz() * consts::C);
-                //let r = 0;
                 let r = scale_signed_to_u8(cell.mat().mz(), 100.0);
                 let b = scale_unsigned_to_u8(cell.mat().conductivity(), 10.0);
-                //let b = 0;
-                //let b = norm_color(cell.ey());
-                //let g = 0;
-                //let g = norm_color(cell.ex());
-                //let g = norm_color(curl(cell.ex(), cell.ey()));
-                //let g = norm_color((cell.bz() * 1.0e4).into());
                 let g = scale_signed_to_u8(cell.bz(), 1.0e-4);
                 image.put_pixel(x, y, Rgb([r, g, b]));
             }
@@ -95,10 +73,11 @@ impl SimStateRenderExt for SimState {
         for y in 0..h {
             for x in 0..w {
                 if x % evec_spacing == 0 && y % evec_spacing == 0 {
-                    let mut vec = self.e_vector(x, y, evec_spacing) * 0.01;
-                    let vec = scale_vector(self.e_vector(x, y, evec_spacing), 100.0) * (evec_spacing as f64);
+                    let norm_vec = scale_vector(self.e_vector(x, y, evec_spacing), 100.0);
+                    let alpha = norm_vec.mag_sq().powf(0.33);
+                    let vec = norm_vec * (evec_spacing as f64);
                     let center = Point::new(x as _, y as _) + Point::new(evec_spacing as _, evec_spacing as _)*0.5;
-                    image.draw_field_arrow(center, vec, Rgb([0xff, 0xff, 0xff]));
+                    image.draw_field_arrow(center, vec, Rgb([0xff, 0xff, 0xff]), alpha as f32);
                 }
             }
         }
@@ -130,24 +109,23 @@ impl SimStateRenderExt for SimState {
 }
 
 trait ImageRenderExt {
-    fn draw_field_arrow(&mut self, center: Point, rel: Point, color: Rgb<u8>);
+    fn draw_field_arrow(&mut self, center: Point, rel: Point, color: Rgb<u8>, alpha: f32);
 }
 
 impl ImageRenderExt for RgbImage {
-    fn draw_field_arrow(&mut self, center: Point, rel: Point, color: Rgb<u8>) {
+    fn draw_field_arrow(&mut self, center: Point, rel: Point, color: Rgb<u8>, alpha: f32) {
         let start = (center - rel * 0.5).round();
         let end = (center + rel * 0.5).round();
         let i_start = (start.x() as _, start.y() as _);
         let i_end = (end.x() as _, end.y() as _);
-        drawing::draw_antialiased_line_segment_mut(self, i_start, i_end, color, pixelops::interpolate);
+        let interpolate_with_alpha = |left, right, left_weight| {
+            pixelops::interpolate(left, right, left_weight*alpha)
+        };
+        drawing::draw_antialiased_line_segment_mut(self, i_start, i_end, color, interpolate_with_alpha);
         //drawing::draw_line_segment_mut(self, i_start, i_end, color);
     }
 }
 
-fn norm_color(v: f64) -> u8 {
-    (v * 64.0 + 128.0).max(0.0).min(255.0) as u8
-}
-
 pub trait Renderer {
     fn render(&mut self, state: &SimState);
 }