For the Maya part, it looks like a z-sorting issue, not a texture thing. Go to Shading above the viewport and select Polygon Transparency Sorting. For Unity, what shader is the material using? For this I would try Transparent > Cutout > Diffuse.
Okay here is the image of what the alpha looks like and the texture. The texture with the alpha is set to a targa 32bit i believe. I put it on my model in maya as a normal lambert the tranparent turned on as well. I filpped the faces on the back so they were face the other way so i could see the colors. But When i look at…
Is your grass modeled to have two sides? a front and back? Polygons will be completely transparent when viewed from the back, unless you apply a "double sided" material to them. In games it's usually better to model transparent objects that will be viewed at all angles with actual back facing polygons rather than use a…