alpha_channels_error

[jbeau]

Alpha channels transparency turns black with multiple billboards in front of one another.
I tried editing the advanced material properties opacity modes and tried this in conjunction with the textures opacity mode, but nothing worked.
I instanced the geo and had the billboards look at the origin. I want to simulate brush, forests, grass, etc

I looks like it happens 3-4 render layers deep.

[jbeau]

I have a temporary solution if I render in passes.

[evilmaul]

have you tried to crank up the Ray bounces in the Setting/advanced tab?  by default is 6 , try like 12 and then up...see if that works