How to use the mask file when you download a 3D model?

Hello! I’m making a rally car scene and need trees, but always I have problems with the transmission of the material for the branches with leaves. When I downloaded the tree 3D model for leaf branch texture it had the usual stuff together with a mask file connected to the transmission of the Principled BSDF. What kind of modification to the material or UV so it works, cause when I use it stock it doesn’t work properly?

Backside of leafs require translucency to get lit, so I wouldn’t use the Principled at all.
Shader mix diffuse and translucent shaders, feed that into upper slot of another mix shader and a glossy in the second, this time mixed with a fresnel node. For correct effect for thin leaves, you need to invert the IOR value for backfacing faces - previewing the fresnel should look identical on both sides of the leaf.

Take all that and put in the upper slot of t third mix shader, with a transparency shader in the bottom slot and the mask texture to drive it.

Big thanks man! I still haven’t checked if it works but I’m sure it will! I am still learning the program so I love when people just like you help. This isn’t related to the main question but could you explain how to put dirt on the rally car from my scene? Also on the wheels. And um also I would be so thankful if you explain how to make dirt smoke (When the rally car jumps it has smoke behind it. How to make that?). I know I’m asking for a lot of things but you would be a hero if you explain them all! Cheers!

There are people here much more experienced with volumetrics than I am, so I’m probably best shut my mouth on this one :smiley:

Well, ok. Still big thanks! I was trying to figure out what was wrong with this guy’s texture for so long. :sweat_smile: