await scene.assets.loadAsset({                 type: 'texture',                 assetId: 'arrow_png',                 src: '',                 options: {                     wrapU: 1,                     wrapV: 1                 }             });             const arrowMat = scene.createMaterial(                 // 使用定制的效果                 scene.assets.getAsset('effect', 'standard'), {                     u_baseColorMap: scene.assets.getAsset('texture', 'arrow_png')                 }             );             scene.assets.addAsset('material', "arrow-mat", arrowMat)             const arrow = scene.createElement(xrFrameSystem.XRMesh, {                 geometry: "plane",                 material: "arrow-mat",                             });             root.addChild(arrow);