In order to do some tests on the polygon card planes I did, I have Layout the UVs and exported them as an PNG to work with it on Photoshop. I created several custom brushes with dots in order to get a proper hair effect and fulfill the surface faster. It seems that brushes with small dots and very separated between them in a row work better in other to make parallel strings of hair. To get a better effect in the hair I activated the variation of the brush size depending on the pressure of the pen. After several tries I saw that is better to start pressing harder the pen in the base of the hair to get a thicker string and then decrease the pressure little by little till the tip of the hair. Was very difficult to draw more or less straight lines, It was good on one hand because it looked more like hair strings but on the other hade was very difficult to control and very often I couldn’t reach the top of the plane. I did several layers of hair with different colors and different lengths leaving the tip of the hair less dense and using dark colours changing on each nee layer to a lighter colour.
Back on Maya I snapped the pivot point in the center of the base of each plane to have more control over them and moving and rotating them from the hair root.
I forgot to give a curvy shape to the planes in order to look less straight. I also soften the edges to smooth the surface I had to unfold each plane on the UV and repeated the whole process of painting.
In order to create the specular map I copied the diffuse map and desaturate the image and then use the grey balance tool to make thinner the hair in whites and left black the rest.
to be able to use transparency I had to change the material to a Blinn material and apply the diffuse and specular map inside the Hypershade menu.