I downloaded a sky mask a while ago so I'm going to use what was included to how to make a new sky mask.
In your Feralheart >> Media >> Textures folder copy and paste one of the images, making sure it's a .png file and 512x512 sized image. Rename it and edit it. I think if you use the colour black then the parts in black will show up transparent in-game.
Then in your Feralheart >> Media >> Materials folder open up the Sky.material file in Notepad. Scroll down to this part:
material Sky/SkyMat
{
receive_shadows off
technique 1
{
pass
{
lighting off
depth_write off
fog_override true
fragment_program_ref Sky_PS
{
param_named_auto skyTop custom 1
param_named_auto skyBot custom 2
}
texture_unit
{
texture skyMask.png
tex_coord_set 0
}
}
}
technique 2
{
pass
{
lighting off
depth_write off
fog_override true
texture_unit
{
colour_op_ex source1 src_manual src_manual 1 0 0 1
}
texture_unit
{
texture skyMask.png
colour_op_ex blend_texture_alpha src_current src_manual 0 1 0 1
}
}
}
}
And replace it with this:
material Sky/SkyMat
{
receive_shadows off
technique 1
{
pass
{
lighting off
depth_write off
fog_override true
fragment_program_ref Sky_PS
{
param_named_auto skyTop custom 1
param_named_auto skyBot custom 2
}
texture_unit
{
texture skyMask.png
}
}
pass
{
lighting off
depth_write off
scene_blend add
fog_override true
texture_unit
{
texture IMAGE.png
scale 0.3 0.3
tex_coord_set 0
}
}
}
technique 2
{
pass
{
lighting off
depth_write off
fog_override true
texture_unit
{
colour_op_ex source1 src_manual src_manual 1 0 0 1
}
texture_unit
{
texture skyMask.png
colour_op_ex blend_texture_alpha src_current src_manual 0 1 0 1
}
}
}
}
Where it says "texture
IMAGE.png" is where you type in the name of your new sky mask. When you're done go File >> Save and it should be good to go.
Hopefully it'll turn out how you want in Feralheart