Hi,

So before three r125, it was possible to smooth the shading of a geometry (imported from Blender) this way:

```
const tempGeo = new THREE.Geometry().fromBufferGeometry( geometry );
tempGeo.mergeVertices();
tempGeo.computeVertexNormals();
geometry = new THREE.BufferGeometry().fromGeometry(tempGeo);
```

The result looked like this (left: before, right: after)

But since the Geometry class has been deprecated, I tried something like this:

```
geometry = BufferGeometryUtils.mergeVertices( geometry );
geometry.computeVertexNormals();
```

But the result (left: before, right: after) is quite different.

Is there any way to get this smooth shading back with a BufferGeometry?

Thanks!