collada2gltf converter can't produce *.json file
<p>I am reading a book: <em>Programming 3D Applications with HTML5 and WebG</em> , it involve a Vizi framework.</p>

<p>All the examples load the <code>*.json</code> file instead of <code>*.gltf</code> file. Why?</p>

<p>When I load <code>*.gltf</code>, it doesn't load any result, and the collada2gltf converters only produce <code>*.gltf</code>, <code>*.bin</code>, <code>*.glsl</code> files and so on.</p>

<p>What should I do?</p>