CesiumJS Interaction

---
name: cesiumjs-interaction
description: "CesiumJS interaction and picking - ScreenSpaceEventHandler, multi-key KeyboardEventModifier input actions, Scene.pick, Scene.drillPick, Scene.pickPosition, mouse and touch events. Use when handling user clicks on the globe, selecting entities or 3D Tiles features, registering modifier-key shortcuts, implementing hover effects, or building drag-based interactions."
---
# CesiumJS Interaction & Picking

Version baseline: CesiumJS v1.142 (ES module imports, Ion token required).

## ScreenSpaceEventHandler

Central class for mouse, touch, and pointer events on the Cesium canvas.

```js
import { ScreenSpaceEventHandler, ScreenSpaceEventType,
  KeyboardEventModifier, defined } from "cesium";

let handler = new ScreenSpaceEventHandler(viewer.scene.canvas);

// Register a click handler
handler.setInputAction((event) => {
  console.log("Clicked at", event.position.x, event.position.y);
}, ScreenSpaceEventType.LEFT_CLICK);

// With keyboard modifier (Shift+Click)
handler.setInputAction((event) => {