ParticleEmitters parented to Bones that are children of other Bones have unexpected behavior

Bug Reports Engine Bugs
#1

Issue Type: Other
Impact: High
Frequency: Often
Date First Experienced:
Date Last Experienced:

Reproduction Steps:

  1. Download and open the provided place file: BoneParticleBug.rbxl (30.3 KB)

  2. Start a server or simulation. You should spawn in as a SkinnedMesh character.

  3. Locate the two ParticleEmitters in the running instance. They can be found here:
    i. Workspace > [YourCharacter] > HumanoidRootPart > LowerTorso > ParticleEmitter1
    ii. Workspace > [YourCharacter] > HumanoidRootPart > LowerTorso > UpperTorso > ParticleEmitter2

  4. Enable both ParticleEmitters. You should see a blue particle generated at a single point inside your character’s lower torso, and a red particle generated in a small volume of space in your character’s upper torso.

  5. Move around and notice that the red particle doesn’t align with your character’s upper torso and it takes up a volume of space rather than a single point.

Expected Behavior:
Expected behavior is for both ParticleEmitters to emit particles from a single point, which in this case would be the TransformedWorldCFrame property of their parent Bone instances.

Actual Behavior:
When a Bone with a ParticleEmitter is parented to another Bone, it causes the particles to emit in a volume instead of a single point.

Additionally, it appears that the particles are emitted from the “WorldPosition” of the Bone instead of the “TransformedWorldCFrame”. This means that Particles will not align properly for any animated SkinnedMesh characters that use them.

StandStill Moved

Workaround:

7 Likes
#2

Thanks for the report! We’ve filed a ticket to our internal database and we’ll follow up when we have an update for you.

4 Likes
#3

Bump.
as of June, this problem is still occuring, and not just with particle emitters, but with any instance visible that’s parented to a child Bone, Smoke,Fire, Particle Emitters and all types of lights.

They usually update once and Never again, and this makes development really hard as it stops me from doing some effects with those objects like i could with Characters rigged using Motor6Ds.

The only possible workaround would be to have the character rigged both with Skinned meshes and separated parts, but that bumps the number of things loaded per character and makes Animations a pain to do, and might cause small performance issues, or to reparent the particle every frame to the bone, but that would kill performance

Please Fix !

4 Likes
#4

Hello! Does this issue occur anymore for any of you, now?

#5

If you are referring you whether the effects follow the bone’s transformedworldcframe or not, it doesn’t move at all. I had been using an alternative method by attaching them to a moving attachment instead.