First of all, allow me to introduce myself to the forum, its my first topic here, but i made a few fpsc projects years ago
Soo, as we all know Fps Creator is VERY limited when it comes to open spaces, let alone grass, plants and foliage... We got a lot of grass and tree models, even whole model packs, but nobody ever uses them. Ya know - foliage and grass models are very fps consuming AND on top of that, often they are bulletproof, even with dedicated scripts. Soo here is my awnser :
Take one of your standard overlays, and change its texture to >whatever you want< in png (or dds) with transparent bacground (you can find them for free, google it) and you can change the scale. And when you change main script to leavecorpse.fpi you can walk and shoot through them! (if they're dynamic of course ). Also they are great for bacground - you can put some 2d planes in the distance and you are no longer wasting your precious memory for decorations

In description i put an example fpe file, cuz i don't want to confuse beginners
https://www.youtube.com/watch?v=ebq6LgjKJbM
Here's a little video with my freshly made 2d foliage, and landscapes. As you can see these retextured merciless enemies have no problemo to navigate and shoot me through leafs... and vice versa

sorry im not giving these for free, but i need it to be exclusive 4 my next fpsc game ;p