# SobelOperatorShader ## Import SobelOperatorShader is an addon, and must be imported explicitly, see [Installation#Addons](https://threejs.org/manual/#en/installation). ```js import { SobelOperatorShader } from 'three/addons/shaders/SobelOperatorShader.js'; ``` ## Properties ### .SobelOperatorShader : ShaderMaterial~Shader (inner, constant) Sobel Edge Detection (see [https://youtu.be/uihBwtPIBxM](https://youtu.be/uihBwtPIBxM)). As mentioned in the video the Sobel operator expects a grayscale image as input. ## Source [examples/jsm/shaders/SobelOperatorShader.js](https://github.com/mrdoob/three.js/blob/master/examples/jsm/shaders/SobelOperatorShader.js)