NPC creation

I’m trying to make a simple npc that acts like a rollermine, but as a 2d ball. can anyone tell me where the rollermine lua is, or how to make this npc? I also do not want it to explode on death, instead to become a standard prop, or just disappear.

I think rollermines are coded in C++ so I’m not sure if you could do it that way, you’d have to just make it from scratch from lua, unless you find someone else who has done it before. Same goes for the hl2 weapons.

then, can you teach me how i can make one from scratch?

Well the reason there isn’t one right now is because scripted NPCs are quite tricky to do well, especially unique NPCs such as the rollermine. Your best (and anyone’s) bet at recreating them in lua would be to recreate them from scratch taking their C++ source as an example and that might or might not be fully possible if it requires some functions not available in lua.
As for HL2 weapons I don’t know if you asked about them but they at least have been fully recreated in lua thanks to CptFuzzies’ SWEP Bases project.

ANYWAY that doesn’t mean you couldn’t resort to hacky, but much simpler, ways to get the result you’re looking for.
What you might want to do is NoDraw the rollermines you spawn and have the sprite of your choosing be displayed at their location (The bouncy ball is a great example of that). For controlling their death you could try playing around with ScaleNPCDamage and OnNPCKilled to change the way they take damage and/or remove them when they die to replace them by whatever you want (or nothing).