ThreeJS - render mesh with curved surface as black and white drawing

Question

I want to render a mesh with curved surfaces like in this image:

Using the EdgesHelper I got this

or, increasing the number of faces and the thresholdAngle of the EdgeHelper:

Any idea?

Answer 1

I found a solution! Following this suggestions Three.js outlines

I used the EdgeHelper plus:

var outline_mat = new THREE.MeshBasicMaterial({color : 0x000000, side: THREE.BackSide});
var outline = new THREE.Mesh(mesh.geometry, outline_mat);
outline.scale.multiplyScalar(1.02);
scene.add(outline);

result: