The goal of the ShadowOnlyMaterial is to display only shadows casted by a light on a receiving object. It is mostly useful when you want to display shadow on a transparent canvas (on top of your existing DOM).
ShadowOnly material can be found here: https://cdn.babylonjs.com/materialsLibrary/babylon.shadowOnlyMaterial.js
A demo can be found here: PG: Shadow Only Material
Using the ShadowOnly material
ShadowOnly material is dead simple to use. Just apply it as material to any mesh where you want to display only shadow:
var ground = BABYLON.Mesh.CreatePlane('ground', 1000, scene)ground.rotation.x = Math.PI / 2ground.material = new BABYLON.ShadowOnlyMaterial('shadowOnly', scene)ground.receiveShadows = true
By default the shadow color is black but you can force an artificial color with
material.shadowColor = BABYLON.Color3.Red().
Demo here: PG: Shadow Only Material
Limitation: Please note that only the first light that can reach the mesh will be used.
So if you have multiple lights in your scene you may end up using
You can also force the material to pick a specific light with
material.activeLight = light.