xrframe, 基础模型上渲染png图片,图片透明部分是黑色怎么处理?

<xr-asset-material asset-id="mat" effect="standard" uniforms:"u_baseColorMap: waifu" states="alphaMode:BLEND" renderQueue="2500" />

仔细看文档：https://developers.weixin.qq.com/miniprogram/dev/component/xr-frame/render/material.html