cocos-awesome/assets/Scene/Infinite_bg_scroll/Infinite_bg_scroll.ts

const { ccclass, property } = cc._decorator;

@ccclass
export default class Infinite_bg_scroll extends cc.Component {
  @property(cc.Node)
  bg1: cc.Node = null;
  @property(cc.Node)
  bg2: cc.Node = null;

  speed: number = 500;
  onLoad() {
    const viewSize = cc.view.getVisibleSize();
    this.bg2.getComponent(cc.Widget).left = viewSize.width
    this.bg2.getComponent(cc.Widget).right = -viewSize.width
  }

  update(dt) {
    const temp = dt * this.speed;
    if (this.bg2.x - temp <= 0) {
      this.bg1.x = this.bg2.x;
      this.bg2.x = this.bg1.x + this.bg1.width;
    }

    this.bg1.x -= temp;
    this.bg2.x -= temp;
  }
}