Need help regarding filters (Solved)

I’m looking to to implement “fog of war” as seen in games like WC3, Age of Empires etc.

After some reading, I’ve decided the way to go is to write a Filter class and a fragment shader.

What I’ll do is have a texture, say, 256x256 size. Where the alpha channel describes which areas are visible and which areas are not. 0,0 in the texture would correspond to the 0,0,0 world coordinate (don’t need Y component of course).

Then, in the fragment shader. I would need to know the world position of the current fragment/pixel, then figure out where this is in the fow texture map and paint the texture accordingly.

Anyway, I’m kinda lost as to how filters work.

In the initFilter method of my filter, I set the material field to a new Material, using my custom FogOfWar.j3md. Where do I get the input texture for the scene?

Ok, so after peeking in the JME3 source code I now have, kind of like the “Identity” program for Filters.