{
  "taskId": "expansion-047",
  "slug": "chair-camera-arc-ground-contacts",
  "language": "zh",
  "mode": "image-to-video",
  "modelId": "MiniMax-H3",
  "evidenceClass": "original-practice-method-not-model-tested",
  "input": {
    "path": "/learning-assets/pseo-expansion70-20261014/chair-camera-arc-ground-contacts/first-frame.png",
    "editableSource": "/learning-assets/pseo-expansion70-20261014/chair-camera-arc-ground-contacts/first-frame.svg",
    "role": "first_frame",
    "sourceType": "original-illustration"
  },
  "intent": {
    "cluster": "Historical camera movement and stationary-subject prompt family",
    "historicalQueries": [
      "minimax h3 camera commands",
      "how to tell to minimax h3 director that the subject does not moves. it keeps walking",
      "minimax h3 image to video"
    ],
    "evidenceRef": "docs/research/pseo-keyword-gap-2026-10-05/evidence/bing-live-keywords.csv",
    "distinctValue": "A short chair-camera arc with one stable chair, four traceable floor contacts and perspective-changing floor seams, differentiating camera movement from chair rotation.",
    "existingOwnerBoundary": [
      {
        "path": "/blog/camera-movement-prompts",
        "difference": "The broad camera tutorial names arcs; this package supplies a four-leg source and explicit foot-to-floor checks across a restrained arc."
      },
      {
        "path": "/blog/product-shape-consistency-video",
        "difference": "The chair task isolates leg count, ground contacts and occlusion during camera motion instead of repeating general product stability advice."
      },
      {
        "path": "/blog/product-video-shot-list",
        "difference": "Only a single inspectable chair arc is specified; no multi-shot furniture campaign is planned."
      }
    ],
    "demandClass": "historical-parent-query; exact long-tail demand unmeasured"
  },
  "title": "椅子小弧线运镜：追踪四个椅脚落地",
  "description": "围绕静止椅子做短弧线运镜，通过腿数、脚底接触和地面缝线，区分视角变化与椅子自行旋转。",
  "goal": "椅子落地固定，摄影机保持高度做短弧线移动。原创练习未通过模型测试，也不能从单图恢复精确三维家具结构。",
  "preparation": [
    "使用四条腿尖端都可辨认的斜侧椅图，后腿也应可追踪。配套细腿椅与地面格线便于观察。",
    "椅子四周留空间，避免运镜裁脚。素材完全藏住某条腿时，先换视角再要求证明四脚落地。",
    "只规划略微转向正面的小幅视角变化，不从一张看不到背面的插画要求完整环绕。",
    "记录各椅脚相对附近地缝的位置。机位变化会改变屏幕坐标，世界中的接触位置仍应固定。"
  ],
  "prompt": "从上传的椅子场景开始。唯一的椅子固定在地面上，四个脚尖持续落地。摄影机保持相同高度及近似距离，沿一小段平滑弧线缓慢移到略微更正面的视角。地面缝线随摄影机自然改变透视。椅子相对缝线的朝向保持不变，不在地上自转。保留四条腿、相连坐面和靠背，视角变化时遮挡关系连贯。结尾机位停稳，椅脚仍落地。椅子不滑移、不折叠，不出现新家具，不推近变焦。",
  "steps": [
    {
      "title": "运镜前标清四个脚",
      "body": "在输入辨认前左、前右、后左、后右四个脚尖。将它们视为同一椅子的部件，不要求四个点在机位变化时保持原屏幕坐标。"
    },
    {
      "title": "分别指定机位与固定椅子",
      "body": "要求相同高度、近似距离的短弧线。把椅子相对地缝的朝向固定，避免变成转台效果。"
    },
    {
      "title": "检查遮挡的变化",
      "body": "弧线中段沿每条腿从坐面连接处追到脚尖。允许投影遮挡合理变化；新长出腿、脚尖悬空或腿与地缝融合都不通过。"
    },
    {
      "title": "结尾对照地面接触",
      "body": "借附近地缝交点判断椅子是否走动或滑动。弧线暴露过多未知结构时，只减小弧线范围，再追踪同样四个脚。"
    }
  ],
  "acceptance": [
    "唯一椅子始终保留四条连贯的腿。",
    "每个可见脚尖持续受地面支撑。",
    "椅腿一直连接原坐面结构。",
    "椅子相对地缝朝向固定，没有自行旋转。",
    "地面透视随短弧线机位连贯改变。",
    "坐面与靠背连接没有折叠、拉伸或左右互换。",
    "结尾完整保留椅子，没有裁脚或继续漂移。"
  ],
  "troubleshooting": [
    {
      "symptom": "椅子像转台一样自转",
      "change": "只把固定要求改成椅子相对地缝朝向不变，保留短弧线运镜。"
    },
    {
      "symptom": "后腿消失或增生",
      "change": "只减小弧线范围，减少暴露隐藏结构，再追踪同一条后腿。"
    },
    {
      "symptom": "椅脚浮在地上",
      "change": "只把接触要求改为四个脚尖持续落地，中段就检查，不能只看结尾。"
    },
    {
      "symptom": "镜头推近只剩坐面",
      "change": "只把路径写成近似等距离、同高度，四个脚周围保留空间。"
    }
  ],
  "ending": "结尾略微更正面，仍可追踪四条腿到落地点。保存起始、中段和结尾的接触记录，不从生成透视推断精确尺寸。",
  "assetCaption": "原创四腿椅与地缝输入，用于弧线运镜练习；这是简报素材，不是生成的机位控制演示。"
}