playcanvas / playcanvas/engine

Particles are not scaled when under a parent entity that is scaled

Open
#3,396 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

area: graphics
Dominant language
JavaScript
Stars
16.8k
Forks
2k
Avg merge
4h 32m
Merged PRs (30d)
222

Description

Not entirely sure this is a bug or not.

Project: https://playcanvas.com/project/822736/overview/test-particles

Same particle effect under 3 different parents of different scales.

https://user-images.githubusercontent.com/16639049/129746363-5526cf9b-b27f-4b2e-906d-94c4cbc4a576.mp4

While the velocity isn't scaled (as there is a concept of world velocity and local velocity), it's not clear how scale should be applied. Is it a world scale or local scale?

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the particle effect in the linked PlayCanvas test project and compare the three parent scales shown in the attached video. Clarify whether particle scale should follow world scale or local scale, then define the expected behavior before identifying the relevant particle-system code and tests.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript
Domain
computer-graphics, game-dev
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.