Fixed partially transparent facades rendering incorrectly

*Resubmission of #1469*

This should fix #1468

![](http://puu.sh/79zPB.png)
![](https://github-camo.global.ssl.fastly.net/dbd8b3e9a080bad7cb924c42e8a329b333c504af/687474703a2f2f7075752e73682f37615632742e706e67)