Get a brown or camo "blue" tarp as the liner, cheap, and water and windproof. Put your grass panels or camo netting over that.
You have to weight the bottom of the tarp/netting combo as wind can lift it, I used net leadline, it helps if it just barely goes under water.
You can vary the height of the bars to get the blind top at the level you want, you can also have folding/swinging top pieces as a roof that will all fold down to the gunnels.