diff --git a/src/shaderview.ts b/src/shaderview.ts
index 7892242..d5523ed 100644
--- a/src/shaderview.ts
+++ b/src/shaderview.ts
@@ -40,6 +40,13 @@ export class ShaderView {
 
     this.finalShader = this.preprocessShaderCode(shaderString);
 
+    const all_uniforms = this.listUniforms();
+    for (const uniform_name of Object.keys(all_uniforms)) {
+      if (!this.uniforms[uniform_name]) {
+        this.uniforms[uniform_name] = all_uniforms[uniform_name];
+      }
+    }
+
     if (!options?.noRender) {
       this.render = new ShaderViewRender(this.finalShader, this.uniforms);
     }
@@ -96,7 +103,7 @@ export class ShaderView {
   }
 
   setUniform(name: string, value: any): void {
-    this.uniforms[name];
+    this.uniforms[name].value = value;
   }
 
   setParent(parent: HTMLElement): void {
diff --git a/web/index.html b/web/index.html
index e655f40..ab5ca26 100644
--- a/web/index.html
+++ b/web/index.html
@@ -3,24 +3,32 @@
     <meta charset="utf-8">
     <script type="module">
       import { ShaderView } from "./mod.js";
+
+      var speed = document.getElementById("speed");
+      speed.onchange = () => view.setUniform("speed", speed.value);
+
       const shader = `
+uniform float speed;
 void main()
 {
     vec2 uv = (gl_FragCoord.xy * 2. - iResolution.xy) / iResolution.y;
     float d = length(uv);
-    d = abs(sin(d * 10. + iTime)) / 10.;
+    d = abs(sin(d * 10. + iTime * speed)) / 10.;
     d = smoothstep(0.95, 1., 1. - d);
     vec3 color = d * vec3(1., 2., 3.);
     gl_FragColor = vec4(color, 1.0);
 }`.trim();
-      new ShaderView(shader, {
+      const view = new ShaderView(shader, {
         parent: document.getElementById("container"),
         size: { width: 512, height: 512 },
       });
+      view.setUniform("speed", speed.value);
+      console.log(view.uniforms);
     </script>
   </head>
 
   <body>
+    <input id="speed" type="number" value="1" />
     <div id="container"></div>
   </body>
 </html>
