"emitting" property doesn't work

[zWolfrost]

When i disable the "emitting" property, the trail doesn't stop. If nothing can be done, is there an alternative to this property, where i can stop emitting while still being able to see the previous trails?

[Kaio20]

So my goal: stop new parts of the trail from emitting.

the "emitting" checkbox from GPU Particles does not work because (?) the trail script is build on top (I got no idea)

The amount and lifetime are set by the length. I can not set the length at runtime or the already exisiting trail is being cut of. How do I stop it from emitting

[stokatyan]

I think this issue has something to do with the following lines of code in trail.gdshader:

if(CUSTOM.w == amount+1.0){
    CUSTOM.w = 1.0;
}

I'm stuck trying to solve this, but my current thought is that the particle system actually does stop emitting, but this restart logic reuses old particles.

[th28]

I think this issue has something to do with the following lines of code in trail.gdshader:

if(CUSTOM.w == amount+1.0){
CUSTOM.w = 1.0;
}

I'm stuck trying to solve this, but my current thought is that the particle system actually does stop emitting, but this restart logic reuses old particles.

I also struggled with this (really nice add-on otherwise though :)). But yeah I think your right, the way it is structured right now seems to ignore the emitting property because it keeps the same group of particles in memory. So even though the emitting property changes to false, it doesn't matter since the particle shader still has the same original set of emitted particles and will keep running using them.

I was able to come up with a hack to make it work for my use case (skid marks in a racing game) by adding a "running" boolean uniform to the trail.gdshader file and using it like below:

if(CUSTOM.w == amount+1.0){
		if(running == true){
			CUSTOM.w = 1.0;
		}else{
			ACTIVE = false;
		}
	}

Then once you set this shader parameter to false, the particles will stop being reused and the trail fades away. This is not enough though because when I tried to turn the particles back on using emitting = true, nothing happened.

I don't really know enough about shaders to debug this further, so I made a system where anytime I need a trail I just initialize a new GPUTrail3D scene rather then trying to mess with the emitting property and reuse the same single GPUTrails3D node over and over again. Then since I am creating a lot of new GPUTrails3D I have some code that deletes the oldest ones to save memory.

Not a very elegant solution but works alright for me so far. Thanks a lot for this project!