diff --git a/app-proto/src/display.rs b/app-proto/src/display.rs
index 14b132a..6f7ac71 100644
--- a/app-proto/src/display.rs
+++ b/app-proto/src/display.rs
@@ -517,7 +517,7 @@ pub fn Display() -> View {
                 
                 // write the spheres in world coordinates
                 let sphere_reps_world: Vec<_> = scene.spheres.representations.into_iter().map(
-                    |rep| &asm_to_world * rep
+                    |rep| (&asm_to_world * rep).cast::<f32>()
                 ).collect();
                 
                 /* SCAFFOLDING */
@@ -554,17 +554,17 @@ pub fn Display() -> View {
                 ctx.uniform2f(resolution_loc.as_ref(), width, height);
                 ctx.uniform1f(shortdim_loc.as_ref(), width.min(height));
                 
-                // pass the assembly data
+                // pass the scene data
                 ctx.uniform1i(sphere_cnt_loc.as_ref(), sphere_cnt);
                 for n in 0..sphere_reps_world.len() {
                     let v = &sphere_reps_world[n];
-                    ctx.uniform3f(
+                    ctx.uniform3fv_with_f32_array(
                         sphere_sp_locs[n].as_ref(),
-                        v[0] as f32, v[1] as f32, v[2] as f32
+                        v.rows(0, 3).as_slice()
                     );
-                    ctx.uniform2f(
+                    ctx.uniform2fv_with_f32_array(
                         sphere_lt_locs[n].as_ref(),
-                        v[3] as f32, v[4] as f32
+                        v.rows(3, 2).as_slice()
                     );
                     ctx.uniform3fv_with_f32_array(
                         sphere_color_locs[n].as_ref(),