Creating Trees and Grass for unity ? How to add alpha layer to Vertex Colors? Ive been working for quite some time in small scene for unity, the scene is in a forest so there is plenty of trees and grass Im creating in Blender.. Im using the same technique in both cases, baking a high detail mesh into low poly planes and using these planes to populate the tree branches or making bushes of grass.

Everything is perfect, but Unity uses Alpha Vertex values to figure out how much those planes will swing with the wind, but Blender apparently doesnt have this feature!! So my tree branches planes and grass swing as a full object, I cant make the bottom vertex fixed because Unity considers they all have the same alpha value.

How can I work around this problem? Ive been looking in the internet for sometime and cant find a solution.

Thanks
If you use one of the recent nightly builds of blender

you can use the Blender Vertex Color Master Addon to get access to alpha channel.

From my quick experiments, the FBX exporter supports vertex colors. They show up in Unity. I couldn't text the animation because you didn't mention what shader you were using.