How to make imported GLB object translucent?

I have a scene that contains Solar System planets. What I want is to put a PointLight inside of the Sun so that the light passes through the model, but the model itself has to be fully opaque. As I understand I need to change “transparent” property to true on the material, but I’m not sure how to access it when importing the model.

        function (gltf) {
          var object = gltf.scene;
          var scale: number = planets.scales[i];
          object.scale.set( scale, scale, scale );	
          var coordinates = planets.coordinates;
          scene.add( object );

That is not necessary. Just add the point light to the sun as a child. It will automatically illuminate objects through the sun’s surface. Try it like so: Edit fiddle - JSFiddle - Code Playground