I'd like to be able to make the default Glass Blocks / Glass Panes act as if the neighboring Block was one of their own types. In case of the Panes it means that the default Panes should connect to Blocks i tell it to connect to. Also, Glass Block should not render their side when you are looking through your own Block.

 

In my Mod i did it this way (replacing the class files as a coremod):

 

https://github.com/BStramke/NetherStuffs/tree/master/src/common/net/minecraft/src

 

its not perfect because i had to use addToSameBlockList(Block.glass.blockID); in my own Glass File, which should be done in the Glass Block (?), look at this file for further info:

 

https://github.com/BStramke/NetherStuffs/blob/master/src/common/NetherStuffs/Blocks/NetherSoulGlass.java

 

https://github.com/MinecraftForge/MinecraftForge/issues/248

 

I already made a fix for this, just waiting on some kind of response on the matter. A few others responded with other, more wide spread fixes.

Actually, this may just fix the issue with Panes, it wouldnt affect the Glass Blocks side Texture rendering. And it is doable with an AccessTransformer, but as i seen its not possible to remove final from methods yet (already posted that as issue).