OBJ + MTL loads but doesn't render

Question

If I use the following code to load the .obj and .mtl downloaded from https://poly.google.com/view/9NXf-SDxJny it works fine, I see the star rendered in my scene.

return new Promise((resolve, reject) => 
    {
        let mtlLoader = new THREE.MTLLoader();
        mtlLoader.crossOrigin = true;
        mtlLoader.setPath(ASSETS_PATH);
        mtlLoader.load(filename + '.mtl', (materials) => 
        {           
            materials.preload();
            let objLoader = new THREE.OBJLoader();
                objLoader.setPath(ASSETS_PATH);

                objLoader.setMaterials(materials);
                objLoader.load(filename + '.obj', (obj) => 
                {   
                    this.obj = obj; 
                    resolve(true);
                });
        });
    });

But when I use the same code to load the obj and mtl from https://poly.google.com/view/4-OZNPuTqFq it doesn't show. I don't get any errors. If I remove the line objLoader.setMaterials(materials); then i see the cake but with no material. So it appears to be a material issue.

I have a codepen with the full code here https://codepen.io/steveg3003/pen/6f0d8c4a17ed12bea49b3391a6d80ce3?editors=0010

Thanks

Is THREE.OBJLoader2.setMaterials throwing an exception or error you can see in your browser console log? Can you see if the materials array is null before you pass it in? — Timothy John Laird
Ok so if I switch to OBJLoader2 I can see the shape but the material is all grey. And I get the following error > THREE.BufferGeometry.computeBoundingSphere(): Computed radius is NaN. The "position" attribute is likely to have NaN values. — steveg
Can you go to the browser and stick a breakpoint where computeBoundingSphere gets called (think 4 places) in BufferGeometry.js? It generates the same error text you saw and I think it's called at some point when objloader2.load gets called. See if it yields any clues. — Timothy John Laird
Any update on this? I see the same problem with aframe and it uses three.js — Omid
@Omid yes, I had to manually change the 'd' value inside the .mtl file from 0 to 1. It appears to set the transparency and for some reason by default the material was set to fully transparent when downloaded from poly.google.com — steveg

steveg steveg · Accepted Answer · 2018-10-20T08:00:50

So the solution for me was to manually change the 'd' value inside the material file (.mtl) from 0.00000 to 1.00000

OBJ + MTL loads but doesn't render

2 Answers