maptalks's version and what browser you use?

v1.0.0-rc.33 Released Chrome

Issue description

自定义瓦片图层放入GroupGLLayer后，当未开启地形时，正常显示，开启地形后，tileLayer.getTileUrl返回的x,y与开启前差别很大

Please provide a reproduction URL (on any jsfiddle like site)

https://codepen.io/knoic/pen/gOJVjPd
就是在官网示例的基础上添加地形