{
  "schemaVersion": 1,
  "taskId": "moving-light-trail-fade-after-stop",
  "creationKind": "original-geometric-illustration-and-method",
  "evidenceClass": "method-not-independently-tested",
  "firstFrameFile": "S01-first-frame.png",
  "reviewGuide": {
    "file": "review-guide.svg",
    "role": "authored intended geometry/review illustration; not a model result and not an uploaded last frame"
  },
  "inputCount": 1,
  "sourceType": "fictional-geometric-practice-not-real-product",
  "input": "The dark input has one mint glowing source near the lower left and four small muted background markers. The glow rings surround the same solid center; the four markers are non-emitting position references. There is no existing trail. review-guide.svg draws an intended curved route with a weaker older tail for later comparison only; it is not a second uploaded image or a generated ending.",
  "anchors": "Track the single solid center as the emitter, the already passed path as the trail, and the four fixed markers as the background. A glow is not permission to duplicate the source. source-trail-observation-roles.json records qualitative roles, not particle lifetime or an alpha-control API.",
  "originalPrompt": {
    "en": "Use the supplied original dark image as the first frame, with one mint glowing point near the lower left and four muted non-emitting background markers. Keep the camera and all four background markers fixed. Move the same single solid light center along one short smooth curve toward the upper right, then stop. A soft temporary trail forms only behind positions the source has already passed. Older parts of that trail gradually become weaker than newer parts nearer the moving source. Keep exactly one solid emitter; do not leave a row of copied solid light balls, create a branching path, draw a permanent line or place the trail ahead of the motion. After the emitter stops, the old trail continues fading until only the one endpoint light remains. Do not cut or replace the background to hide the fading. This is an untested visual-effects request, not a physical particle simulation, exact lifetime or frame-by-frame opacity guarantee.",
    "zh": "使用提供的原创深色图片作为首帧，左下附近只有一个薄荷色发光点，背景有四个暗淡、不发光的定位点。固定相机和四个背景定位点。同一个实心发光中心沿一条短而平滑的曲线朝右上移动，然后停住。柔和临时尾迹只在光源已经经过的位置后方形成。较老尾部逐渐比靠近运动光源的新尾部更弱。始终只有一个实心发射源，不留一排复制实心光球，不分叉，不画永久实线，也不把尾迹放到运动前方。光源停下后，旧尾迹继续淡去，直到只剩终点唯一光点。不切镜，不替换背景来隐藏淡出。这是未实测的视觉特效要求，不是物理粒子仿真，不保证精确寿命或逐帧透明度。"
  },
  "steps": {
    "en": [
      "Confirm the clean first image has one source and no tail. Keep the separate path guide local; a user-facing first-frame action should upload only S01-first-frame.png.",
      "Describe one short smooth curve toward the upper right with a final stop. Exclude a camera move, branching path and extra emitters so the source and residual marks can be reviewed separately.",
      "For a future clip, follow the solid source frame by frame, then inspect positions it has already passed. The trail should follow behind rather than appear ahead of the source or become a chain of solid balls.",
      "Review after the source stops. Older trail portions should keep fading while the single endpoint remains; a bright final streak that never weakens fails this requested ending."
    ],
    "zh": [
      "确认干净首图只有一个光源，没有拖尾。路径图留在本地；页面首帧操作只上传 S01-first-frame.png。",
      "只要求沿短而平滑的曲线朝右上运动并停住。去掉相机运动、路径分叉和额外发射源，让本体与残影可分开检查。",
      "以后有实际片段时，逐段跟踪实心光源，再看它已经经过的位置。拖尾应留在后方，不能提前出现在未来路径，也不能变成一排实心光球。",
      "光源停止后继续观察。旧尾迹还应逐渐淡去，最后保留唯一终点光源；永久发亮不减弱的长线不符合本次结尾。"
    ]
  },
  "acceptance": {
    "en": [
      "Only one solid emitting center exists and its position can be followed continuously.",
      "The four muted background markers stay fixed and do not become extra lights.",
      "A trail appears behind already passed positions, never in front of the moving source.",
      "Older tail sections weaken rather than accumulating as a permanent solid line.",
      "After the source stops, residual trail portions continue fading instead of leaving solid duplicates.",
      "The ending keeps the single stopped emitter and stable background without a cut."
    ],
    "zh": [
      "始终只有一个实心发光中心，位置可连续追踪。",
      "四个暗淡背景定位点固定，不变成额外光源。",
      "尾迹留在已经经过的后方，不提前出现在运动前方。",
      "较老尾部逐渐减弱，不积成永久实线。",
      "光源停止后，残留尾迹继续消退，不留下实心副本。",
      "结尾只有一个停止光源，背景稳定，没有切镜。"
    ]
  },
  "ending": {
    "en": "Keep notes for moving-source identity, older tail weakening and the post-stop interval. A static endpoint light alone does not show whether a trail formed and faded correctly.",
    "zh": "分别记录运动光源身份、旧尾部减弱和停止后的片段。一个静止终点光源本身，不能证明拖尾曾正确形成并淡去。"
  },
  "modelGeneration": "not-executed",
  "paidCalls": 0,
  "outputMedia": [],
  "sourceBriefRef": "S14-next-original-task-briefs-20261022-02#moving-light-trail-fade-after-stop",
  "exactTaskSearchVolume": null,
  "extraObservationSources": [
    "source-trail-observation-roles.json"
  ]
}