particle op• 資料種類:table → table
• 呼叫: import fullseye as fs; fs.ledger.particle_step(state, dt, gravity=(0.0, 98.0), drag=0.0)(要直接呼叫實作,import gfx2d; gfx2d.particle_step(state, dt, gravity=(0.0, 98.0), drag=0.0);從台帳取用則 opsgfx2d.get("particle_step"))
把粒子狀態推進 dt 秒。回傳新的 dict。
> 以下的詳細說明為原文 —— 摘要與標題已翻譯。
Semi-implicit (symplectic) Euler::
v <- v + (g - drag*v) * dt
p <- p + v * dt
age <- age + dt
which makes the closed form exact and checkable: with gravity=(0,0) and drag=0 the position after k steps is p0 + v0*k*dt, and with drag the speed is v0 * (1 - drag*dt)**k. Both are compared as equalities in the test suite.
gravity is (gx, gy) in px/s^2, positive gy pulling down the screen. The input dict is never mutated.
Raises ValueError: dt <= 0; drag * dt >= 1, which is the point where explicit drag stops decaying the speed and starts reversing it — an instability that otherwise shows up as particles flying backwards rather than as an error.
• 範例資料目錄(下載 URL / 授權) —— 2-D 用 skimage.data(BSD/公有領域)加合成圖,3-D 給出真實資料源(Stanford/PDS 等)的下載 URL。
• 運算子來歷與參考文獻 —— 該運算子族所依據的研究/方法出處。
• 演算法的正典(作者、年份)與用途見上面的族使用指南。
• gfx2d_scene — py -3.11 examples/gfx2d_scene.py
table 作為輸入)particle)particle_emit · particle_render
*Provenance: gfx2d.py — GFX2D 運算子登記表。本條目由 tools/opdocs.py md 自動產生(請勿手動編輯)。*
© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.