This material can receive shadows, but otherwise is completely transparent.
const geometry = new THREE.PlaneGeometry( 2000, 2000 );
geometry.rotateX( - Math.PI / 2 );
const material = new THREE.ShadowMaterial();
material.opacity = 0.2;
const plane = new THREE.Mesh( geometry, material );
plane.position.y = -200;
plane.receiveShadow = true;
scene.add( plane );
[example:webgl_geometry_spline_editor geometry / spline / editor]
[page:Object parameters] - (optional) an object with one or more properties defining the material's appearance.
Any property of the material (including any property inherited from [page:Material]) can be passed in here.
See the base [page:Material] classes for common properties.
[page:Color] of the material, by default set to black (0x000000).
Whether the material is affected by fog. Default is `true`.
Defines whether this material is transparent. Default is `true`.
See the base [page:Material] classes for common methods.
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]