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Particle cases

A particle case, asset_kind = "particle-2d" or "particle-3d", produces a particle effect: the model authors an emitter system the review UI and a game simulate live, using the particle binaries. It declares a [particle] table in place of [canvas] or [voxel], and declares no [model]. A case authors one effect.

Everything on the Manifests overview applies unchanged.

asset_kind = "particle-3d"


# The field the effect plays in and how it is played back. A particle-2d case gives
# width/height only; particle-3d adds depth.
[particle]
width       = 48             # extent along x (required, > 0)
height      = 48             # extent along y — up (required, > 0)
depth       = 48             # extent along z (required for particle-3d; forbidden for particle-2d)
duration_ms = 1500           # the effect's length in milliseconds (required, > 0)
fps         = 60             # the preview/playback frame rate (required, finite and > 0)
loop        = false          # one-shot (an explosion, default) or looping (fire, smoke)
background  = "transparent"  # preview clear color only


[tool]
binary  = "particle-3d"      # the particle binary: particle-2d | particle-3d
preview = "effect.gif"       # where the binary writes the preview animation


[output]
actions = "actions.json"     # the recorded op record

The particle table

Section titled “The particle table”

[particle] fixes the field the effect plays in and is required for, and only for, a particle case.

  • width and height bound the field and must be positive. depth is required and positive for particle-3d, and rejected for particle-2d.
  • duration_ms is the effect’s length in milliseconds and must be positive.
  • fps is the preview and playback frame rate and must be finite and positive.
  • loop selects a looping effect such as fire or smoke over the one-shot default.
  • background is the preview clear color.

There is no simulation seed. A particle effect is simulated live rather than baked, so it varies slightly from one play to the next, exactly as a real particle editor plays a system.

Core emits the authored system.json, the emitter, force, and curve definition the review UI and a game simulate live. It is not manifest-declared.