Trying to make "blueprint" props

So for my gamemode I’m trying to make a prop that basically acts like a “blueprint” or “ghost”. The reason I’m calling it a blueprint is because once you have the resources needed, you will be able to build the blueprint to make it “real”. Other specifics of this are that the prop will only collide with the world, NPCs will not act like it’s an obstruction, bullets and weapons will not affect it, and yet you should still be able to interact with it through tracing and by moving it around with gravgun or physgun. I also want other players to be able to see it too so clientside models are out of the question.

I’ve tried going at it in a couple different angles, but they never quite turn out like how I want it. I tried using collision groups and messing with the physics, movetype, and solid-ness of the prop, but I just can’t get it right. The main problem is that as long as it’s traceable, NPCs will always see it as an obstacle and bullets will always hit it. I found that props become untraceable when you make them not solid. Unfortunately, once these props are not solid anymore, they are free to fall right through the world.

Now ideally I would like to be able to freeze and unfreeze these props by pressing a certain key and would like if you had to use the gravity gun to move them around. I would also like them to have physics and collide with the world, but at the same time be untraceable so NPCs and bullets don’t interact with them. However, I’m open to alternative ways to have “blueprint” props work or even completely different ways to spawn props for my gamemode.

Any ideas? Thanks.


Just apply wireframe texture to it.

Wow, you actually solved all my problems without reading any of the post! /s

Why are you even trying to “help” if you can’t bother reading the post?

Also that’s a pretty tough problem right there, I don’t think it’s possible to do exactly what you want to do, but the best you can do is use the ShouldCollide hook to get your entity to collide only with the world. If I remember correctly, this should make bullets go right through it because of the way FireBullets works, although other traces will still collide with it. NPCs will still see it as an obstacle though, and I don’t think there’s a way around that.

Just keep in mind that ShouldCollide is a shared gamemode hook. You also need to call SetCustomCollisionCheck(true) on your blueprint entity on both the server and the client. As for only allowing collisions between a blueprint entity and the world, check if one of the two entities is a blueprint. If it is, return true if the other entity is the world, false otherwise. Else, return nothing, so other collisions don’t screw up.

-snip misunderstood op

Thanks, that helped a lot. I just made it so that if NPCs get near enough to the prop, it will become not solid and will freeze in place. This allows the NPCs to walk through it and then once they have, it becomes solid again and unfreezes. It’s a little sketchy, but it’s working well!