运动路径Motion Path

难度LEVELL3 · 高级L3 · Advanced 领域TOPIC视觉特效

先学：Prerequisites: 变换节点

学习目标LEARNING OBJECTIVES

学完你能用 Transform 节点的 Center 关键帧生成运动路径（Motion Path），并在查看器里直接拖点调整轨迹形状。

概念说明CONCEPTS

运动路径（Motion Path）是给 Center X/Y 打关键帧后自动画在查看器里的轨迹线——元素沿这条线运动，线上的点对应各关键帧。

  • 打键即画线：Transform 节点的 Center 有两个以上关键帧，查看器中就出现轨迹线。
  • 控制点对应关键帧：路径上每个控制点（Control Point）就是一个关键帧的位置，拖动即改落点。
  • 加点不动节奏：Command-点击（Windows 用 Alt-点击）路径，可加一个不生成关键帧的控制点，只改形状不改时间。
  • 形状与节奏分离：路径管"走哪条线"，关键帧管"何时到哪"——两者可以独立调整。
  • 一键变圆滑：查看器工具栏点 Select All Points 全选，再点 Smooth（或按 Shift-S），折线变弧线。

操作步骤STEPS

  1. 选中 Transform 节点并回到起始帧，在查看器中把元素拖到起点位置
  2. 在 Inspector 点击 Center 右侧的 Keyframe 按钮落下第一键给 Center 参数打第一个关键帧
  3. 移动播放头到新帧，在查看器里直接拖元素到下一位置——新键与路径线自动出现
  4. 重复上一步放完所有途经点，按空格预览整段运动
  5. 点击工具栏 Select All Points，再点 Smooth 或按 Shift-S 让转弯变圆滑查看器里平滑前后的运动路径

练习PRACTICE

  1. 让一个图形沿三点"之"字形路径移动，再用 Smooth 变成弧线并对比两版。
  2. 用 Command/Alt-点击在路径中段加一个控制点拖出绕行的弯，回放确认节奏没变。

常见问题FAQ

查看器里看不到路径线？

确认 Center 已有两个以上关键帧，并把该节点拖进查看器显示。还不会打键的话先看 关键帧与动画。

拖路径上的点会打乱节奏吗？

不会。拖动只改空间位置；Command/Alt-点击加的点甚至不生成关键帧，播放节奏完全不变。

能让元素沿路径自动转向吗？

能。右键 Angle 参数选 Connect To > Path > Heading，元素朝向会随路径弯曲自动变化。

Learning Objectives学习目标

After this card you can build a Motion Path by keyframing a Transform node's Center, and reshape the path by dragging points right in the viewer.

Concepts概念说明

A Motion Path is the trajectory line Fusion draws in the viewer once Center X/Y has keyframes — the element travels along this line, and its points correspond to your keyframes.

  • Keys draw the line: two or more keyframes on a Transform node's Center make the path appear in the viewer.
  • Points match keyframes: every Control Point on the path is one keyframe's position — drag it to move that spot.
  • Add points without touching timing: Command-click (Alt-click on Windows) the path to add a control point that creates no keyframe — shape only.
  • Shape and timing are separate: the path decides which line to travel; keyframes decide when to arrive — adjust them independently.
  • One click to round corners: use Select All Points in the viewer toolbar, then Smooth (or Shift-S) to turn corners into curves.

Steps操作步骤

  1. Select the Transform node, go to the first frame, and drag the element to its start position in the viewer
  2. In the Inspector, click the Keyframe button next to Center to drop the first keySetting the first Center keyframe
  3. Move the playhead to a new frame and drag the element to its next spot — a new key and the path line appear automatically
  4. Repeat for every waypoint, then press Spacebar to preview the move
  5. Click Select All Points in the viewer toolbar, then Smooth (or press Shift-S) to round the turnsThe motion path before and after smoothing

Practice练习

  1. Move a graphic through a three-point zigzag, then Smooth it into an arc and compare both versions.
  2. Command/Alt-click the middle of the path to add a control point, pull out a detour, and confirm the timing stays unchanged.

FAQ常见问题

Why can't I see the path in the viewer?

Make sure Center has at least two keyframes and the node is loaded in that viewer. New to keyframes? See Keyframes & Animation first.

Will dragging path points mess up my timing?

No. Dragging only changes spatial positions; points added with Command/Alt-click don't even create keyframes — timing is untouched.

Can the element turn automatically along the path?

Yes. Right-click the Angle parameter and choose Connect To > Path > Heading — orientation follows the path's curves on its own.

深度资料：运动路径 →Deep dive: 运动路径 →

本卡术语Terms in this card

检查器Inspector 关键帧Keyframe 播放头Playhead 曲线Curves Fusion 合成Fusion 节点Node 变换Transform