glTF renders incorrectly, but correct in McCurdy viewer

Can anyone help me debug a glTF file? It looks ok in Don McCurdy’s glTF viewer at https://gltf-viewer.donmccurdy.com/ (though it’s pretty different from how it looks in Blender) but most of its pieces are missing when I use aframe to look at it: https://sgouros.com/scorpii/index1.html.

Two of the meshes are visible, but something has happened to the other dozen meshes. I’m not sure if this is a support question or a complaint about the glTF display feature of aframe, so I’ve posted it here as well as at SO: https://stackoverflow.com/questions/59852899/gltf-file-renders-incorrectly-in-aframe

The model is at https://sgouros.com/scorpii/data/scorpii3.glb, but it looks like this in the McCurdy viewer:

Displayed like this:

    <a-scene id="mainScene"
             background="color: #666666"
             renderer="antialias: true;
                       colorManagement: false;
                       logarithmicDepthBuffer: true;"
             environment>
      <a-assets timeout="20000">
        <a-asset-item id="uscorpii"
                      src="data/uscorpii2.glb"
                      crossorigin="anonymous">
        </a-asset-item>
   ...
     <a-entity gltf-model="#uscorpii"
                scale="1 1 1"
                position="0 0 -15"
                animation="property: object3D.rotation.y;
                           to: 360; loop: true;
                           easing: linear; dur: 136000">
  

• A-Frame Version: 1.0.3
• Platform / Device: Firefox, Chrome
• Reproducible Code Snippet or URL: See links above

[donmccurdy]

This model requires depthWrite=false on any transparent materials. A quick patch would be:

model.traverse((o) => {
  if (o.isMesh) o.material.depthWrite = !o.material.transparent;
});

I’ve implemented that in my viewer, and proposed a fix for threejs (https://github.com/mrdoob/three.js/pull/18235) but the threejs version has not been merged yet. This could be done in a custom component, in the meantime.

[dmarcos]

@donmccurdy Thanks for clarifying. Much appreciated as always.