lightmap: create shadows from alpha texture

Unity Engine
1

Hello guys,
I have a scene with a room,
the walls are made of textured metal grill panels,
the texture has alpha channel, I used transparent alpha and court out okay in the display, but when I ligthmap, the shadows are not ???,
shader which should I use?, which setting?
thanks

2

Try using a Transparent/Cutout shader.

3

ok, thanks, now try,
ok, There is a double side + alpha shader?

4

I don’t mind if the post have 2 years old.

For a 2 sided textures with shadows :
Duplicate the pane and invert the faces in your 3D editing program
Then set a transparent - cutout shader.