Well no the decals dont have any trans at all NOW the CANOPY glass does. Its is a really weird thing. Can I change to software instead of open GL ?
Are you sure? Not even a little alpha? Not even sharing a map that has alpha for some part? A layer list may count as well depending on the layer mask.
As Design Acrobat says, it’s pretty tough to sort this out and have any realtime performance. Maybe in a few years.
However, I use this method for getting quick AO renders and it may help you.
Setup a fully opaque simple white shader and save it to your browser.
Save your finalised shaders/master shaders that are giving you trouble to the browser too.
Now BACKUP your file, just in case.
Drop the opaque shader onto all of the surfaces of the offending model and save THAT new master shader into the browser.
You can now swap between base shaders and complex shaders at will.
This takes longer to type than to do and is convenient for all sorts of things including basic layer rendering, mask production and faster test renders.