For my zombie Game I took this nice flame-thrower particle effect

It's basically a bunch of particles flying around (currently CPUParticles2D but moving it to GPUParticles2D).

But how would I go for collision here?

As I understand GPUParticles2D have collision with LightOccluder2Ds. Can this be used for game logic? I wanna set my Zombies on Fire 🔥!!

I can't use a raycast, because the flame moving around in curves when rotating a lot.
Using (invisible?) collision particles would probably be inaccurate and would defeat the purpose of particle system.

Or am I completely on the wrong track here?

    mojomajor As I understand GPUParticles2D have collision with LightOccluder2Ds.

    I know particles3D has collision, so 2D probably does too.

    mojomajor I wanna set my Zombies on Fire 🔥!!

    but for this I would instead make it so that when the zombies are hit they spawn a particle emitter of their own.
    for handling collisions, use an Area2D or Raycast.

    mojomajor I can't use a raycast, because the flame moving around in curves when rotating a lot.
    Using (invisible?) collision particles would probably be inaccurate and would defeat the purpose of particle system.

    particles are not meant to interact with the environment. the collision is merely visual. I looked it up and CPUparticles has no way to obtain a given particle's position or other information.

    for this particular case, you have to use invisible Area2D or RigidBody2D nodes. they don't have to be 1-1 with the particles, you can emit a big one for every n number of particles.
    this is how most games do it.

      Like he said, separate the collision logic and the visual effect. Particles have to be performant so they don't have all the properties of other game objects.