How about you just make a new
SpatialMaterial, set the
transparent flag, then convert that into a
But I might as well tell you what's going on.
ALPHA value determines the transparency of the currently processed pixel.
ALBEDO determines the color(along with some other variables). How this shader got the colour from the texture is from this line of code.
vec4 albedo_tex = texture(texture_albedo, base_uv);
The first three components of this vector contain the colour itself (.rgb), which is used here.
ALBEDO = albedo.rgb * albedo_tex.rgb;
The last component contains the alpha channel (.a), which you can use by adding this line of code.
//This is what you add in the shader.
ALPHA = albedo.a * albedo_tex.a;
And like that, you have transparency.