Manually spawn particle at position

Help
,
1

Godot Version

4.3

Question

Im trying to manually spawn a particle of an already existing GPUparticlesystem at a specified position.

image

I get positions from the world just fine, its just the spawning that is bugging me.

var tp = raycast_to_world(p)
var t = Transform3D.IDENTITY
t.origin = tp
particles.emit_particle(t,Vector3.ZERO,Color.WHITE,Color.WHITE,0)

this code just spawns particles at 0.0.0

(if i replace the emit code with an instantiate() all that, the tp i get from raycasting are fine)

Has anyone got experience with this?

2

I not sure if that is the problem but you’re using an invalid flag, doesn’t exist the flag 0 for this function, always use the enumerators to avoid this, try:

particles.emit_particle(t, Vector3.ZERO, Color.WHITE, Color.WHITE, GPUParticles3D.EMIT_FLAG_POSITION)

1 Like
3

i will try this! thanks.

4

hmm didnt help. the particles (i think there are many on top of each other, but i could be wrong) does spawn somewhere else though.

what im doing is this (which works perfectly well if i just spawn objects at those positions):

	for row in range(grid_size):
		for col in range(grid_size):
			var tp = round(target.global_position)
			var p = tp - Vector3(grid_size * resolution / 2, 0, grid_size * resolution / 2) + Vector3(row * resolution, 0, col * resolution)
			
			p.x = round(p.x)
			p.z = round(p.z)
			
			var terrain_position = raycast_to_world(p)
			var t = Transform3D.IDENTITY
			t.origin = terrain_position
			#Here ive deleted my original spawn objects code (which works)
			#I even try this out of desperation--->
			#particles.global_position = terrain_position
			#particles.process_material.emission_shape_offset = terrain_position
			particles.emit_particle(t,Vector3.ZERO,Color.WHITE,Color.WHITE,GPUParticles3D.EMIT_FLAG_POSITION)
5

Hm i have no idea, i tested the function with the correct flag and the particle was spawned in the correct place, from your print your GPUParticles3D has a particle material assigned, try remove the particle material and make sure you’re drawing something in the draw pass 1

6

Ok so I guess the p mat has some placement logic in it…
wonder if I then have to learn how to do my own p mat where position is not being set.

7

Nothing works. Now I got a basic process shader for the particle system. And it seems like it still just spawns one particle at one spot.

It seems I can’t do the emit particle call 64 times a frame and manually set positions before each of those calls.

8

Did you try to spawn multiple particles in one frame at different specific positions?

9

Yes, if the amount property in GPUParticles3D is equal or bigger the amount of particles i spawn they work as expected

1 Like
10

Oh… The amount. I’ll try this ASAP. Thanks!

11

Worked. Thanks so much. Didn’t even cross my mind. :smiley::smiley:

12

Wasn’t that ASAP but glad that worked haha

1 Like
13

Indeed. Hobby project time works in mysterious ways. :no_mouth:

14

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.