Create a GLSL texture

 To make a GLSL texture, you need 4 textures

First texture

Is the original texture 

Second texture

It should be a normal map to provide details, you can make it using Gimp or Photoshop

Texture number three,command area or also fill it with black texture

Texture number four ,sphere map for pbr efect based on sphere map

The final texture must have an Alpha value as transparent, if there is no transparent value the texture cannot be loaded into the game

Or you can also make it here Create GLSL TEXTURE