unity5.2版本烘焙Terrain, 阴影不清晰。

unity5.2版本烘焙Terrain, 阴影不清晰。terrain提示渲染精度不够,请问我要提高哪里的参数呢? 我GI的分辨率是40!!
Unity5.2 version for Terrain, the shadow is not clear. Terrain render prompt precision is not enough, could you tell me where I want to improve the parameters? The resolution of the GI is 4066018-5.jpg

66018-5.jpg