bug: 官方例子中CustomPrimitive不显示问题

官方例子--数字城市（earth-digitalCity.html)中createBasePoint方法中的效果不显示

// 底面动态辐射波
{
const evalString = `
p.canvasWidth = 512;
p.canvasHeight = 512;
setTimeout(() => {
p.drawCanvas(ctx => {
ctx.clearRect(0, 0, 512, 512);
ctx.strokeStyle = "rgb(255, 0, 0)";
ctx.setLineDash([80, 80]);
ctx.lineWidth = 30;
ctx.arc(256, 256, 241, 0, Math.PI * 2, true);
ctx.stroke();
});
}, 0)
`;
const preUpdateEvalString = `
if (typeof p.dAngle === 'undefined') p.dAngle = 0.0;
if (typeof p.dt === 'undefined') p.dt = 0.01;
p.dAngle += 10.0;
if (p.dAngle > 360.0) {
p.dAngle = 0.0;
}
p.rotation[0] = p.dAngle / 180.0 * Math.PI;
p.dt += 0.02;
if (p.dt > 1.0) p.dt = 0.01;
p.scale[0] = 50 * p.dt;
p.scale[1] = 50 * p.dt;
`;
const config = {
evalString,
preUpdateEvalString,
position: position,
scale: [50, 50, 1],
positions: [...XE.Obj.CustomPrimitive.Geometry.unitSquare.positions],
sts: [...XE.Obj.CustomPrimitive.Geometry.unitSquare.sts],
indices: [...XE.Obj.CustomPrimitive.Geometry.unitSquare.indices],
renderState: XE.Obj.CustomPrimitive.getRenderState(false, false),
color: [1, 1, 1, 1],
canvasWidth: 512,
canvasHeight: 512
};
let p = new XE.Obj.CustomPrimitive(this.earth);
p.xbsjFromJSON(config);
}

Open the official Digital City example in earth-digitalCity.html and inspect createBasePoint, especially the CustomPrimitive configuration and its evalString/preUpdateEvalString callbacks. Run the example and compare the expected base dynamic radiation wave with the current rendering. Done means the effect is visible and animates as intended.

Written by the indexing model from the issue text.