Bullet Hitscan effect FPS

Unity Engine
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1

In my fps, I am attempting to create a glowing effect across a path when the player fires a weapon, not muzzle flash, but hitscan bullet tracers. Currently I have a trail renderer that has emission and post processing bloom that moves toward the impact point in an update method and spawns a hit effect when it hits, but the first frame of the trail renderer causes a ball at the point where it spawns, which looks just like a continuous ball at that point at high fire rates. Not sure how I could fix this. Regardless, no matter what I do, I can’t get a hitscan tracer effect that looks good, like in other FPS games. Obviously I’ll never achieve the quality of a AAA game, but not sure how to make a good looking effect. There are tutorials for hitscan tracers online, but nothing that looks good, like you’d find in a basic FPS game, and in some tutorials online, I see people with controllers that spawn really good looking effects. Should I use particle system, or line renderer, or trail renderer? With a small particle system that moves toward the point, even an emission rate of 5,000 looks bad with small smoke particles.

Screenshot 2025-03-11 225224
Screenshot 2025-03-11 2252241173Ă—665 116 KB

2

Wouldn’t a line renderer make more sense than a trail renderer?

3

Using a line renderer results in edges of the lines that can be seen crossing the screen as you move around, which doesn’t look particularly good, and both line and trail renderers look very strange when they are thin, I assume this is caused by the post process bloom.

4

I actually like a Particle System with Emit Over Distance set.

It’s especially cool for if you want it to fade in an interesting way.

I don’t have a hitscan sample available but this is it in a projectile-in-flight:

and a slightly higher-velocity one:

1 Like
5

Particle effects are a good idea too.

Could probably do some interesting stuff with the newer VFX graph as well. Been using that over the particle system component lately and don’t think I’m going back.

6

I use a trail renderer for the tracer effect and I’ve not had any issues. I don’t have to do anything fancy to make it work and so I’m wondering if you’ve made unnecessary changes to the default trail renderer settings.

7

I spawn a trail renderer at the edge of the weapon and over time move it a certain amount through a script towards the hit point. I think it is caused by adding a value for end cap vertices because without it there does not seem to be any frames where you can see the end of the trail as it spawns, but with end cap vertices, when it spawns, you can see the ball made by the end cap each time it spawns. Without it, though, you can see the square edges of it as it moves through the air. I like trail renderers, but I have no idea how to not have this happen. Also, thin parts of a trail renderer seem to look bad as it tapers off.
[video-to-gif output image]

8

Yeah that may be the issue. With my tracer I don’t cap the vertices and I don’t taper it. Instead I make the texture image itself taper similar to a tear drop…