Use downloadjs.

package.json

@@ -20,6 +20,7 @@
     "budo": "^10.0.4"
   },
   "dependencies": {
+    "downloadjs": "^1.4.7",
     "three": "^0.88.0",
     "three-vignette-background": "^1.0.3"
   }

src/index.js

@@ -4,6 +4,7 @@ const Tree = require('../lib/proctree');
 const dat = require('../lib/dat.gui.min');
 const DEFAULT_CONFIG = require('./config');
 const Viewer = require('./viewer');
+const download = require('downloadjs');
 
 class App {
   constructor (el) {
@@ -119,12 +120,7 @@ class App {
     exporter.parse(this.viewer.getTree(), (buffer) => {
 
       const blob = new Blob([buffer], {type: 'application/octet-stream'});
-      const link = document.createElement('a');
-      link.href = URL.createObjectURL(blob);
-      link.download = 'tree.glb';
-      link.click();
-
-      setTimeout(() => URL.revokeObjectURL(link.href), 1000);
+      download(blob, 'tree.glb', {type: 'application/octet-stream'});
 
     }, {binary: true});
   }

src/viewer.js

@@ -28,6 +28,8 @@ class Viewer {
     this.controls.autoRotate = true;
     this.controls.autoRotateSpeed = -5;
     this.controls.enablePan = false;
+    this.controls.minDistance = 1;
+    this.controls.maxDistance = 90;
 
     this.background = createVignetteBackground({
       aspect: this.camera.aspect,

style.css

@@ -1,4 +1,6 @@
-html {
+html,
+body {
+  overflow: hidden;
   font-family: Raleway, Helvetica, sans-serif;
   font-weight: 300;
 }