MTLLoader load textures not complete

Questions
5

Updated codesandbox: model-viewer (forked) - CodeSandbox

The problem is that the MTL contains this statement for the materials diffuse color:

Kd 0.00 0.00 0.00

The consequence of this setting is explained here: OBJLoader + MTLLoader not loading texture image - #4 by Mugen87

For now, I’ve manually resetted the color property to its original value.

Besides, use OBJLoader instead of OBJLoader2 (which has been removed with r125).

  new MTLLoader().load(mtlPath, function (materials) {
    materials.preload();
    new OBJLoader().setMaterials(materials).load(objPath, loadSuccess, undefined, onError);
  });

Or even better, use glTF instead of OBJ.