Observing fast moving Particles2D from a fast moving object causes visual glitch.

[UltyX]

bugsquad edit: issue is still present in 3.0 Reproduction project is in this comment: #6373 (comment)

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Linux Kubuntu 14.04 Godot v2.1stabel

Issue description: Observing fast moving particles from a fast moving object that goes in the same direction makes the particles look jumpy like they are in two places at once.

Steps to reproduce:
Add player (rigid or kinematic body) and move it fast in one direction with attached current Camera2D.
Add Particles2D to the world and set set_initial_velocity( player.get_linear_velocity() ) and set set_pos(player.get_pos() ).

Link to minimal example project:
moving_particels.tar.gz
( spawns particles on hit return )

Use case: Creating hit debris in a space shooter that fly s independent alongside of the ship.

[UltyX]

If you're just gonna set it's velocity the same as the player, why don't parent it to the player?

So when the player turns the particles keep their speed and direction independent of the ship since they are not attached to it.

[bojidar-bg]

Can confirm from time to time on my game planetoidee. It looks like it is related to global coordinates in my case at least.

[kubecz3k]

Can you guys confirm it's still present in 3.0?

[UltyX]

The bug is still present. I made a 3.0 compatible minimal example and tested it with alpha 1 and a build of todays master branch. There also might be another 3.0 related bug in the particle system, spawning the test particles had some randomness in its velocity even though I turned all attributes relating to randomness to 0.

Minimal example:
particels.tar.gz

[kubecz3k]

@UltyX thank you for test and example

[ghost]

The reproducing project is no longer working with the current master 9ad1800. With some code changes it still shows some visual glitches but I'm not sure if it's the same as described by OP.

[UltyX]

This bug is no longer present in the 3.2.beta4 version of the engine. I updated the reproduction example in case this becomes relevant again in the future.

Minimal example (resolved):
particels.tar.gz