合成Compositing

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

先学：Prerequisites: Merge 节点

学习目标LEARNING OBJECTIVES

学完你能说清合成（Compositing）是什么，并按"底图 + 叠加 + 匹配"的思路完成一个可信的合成镜头。

概念说明CONCEPTS

合成（Compositing）是把两个或多个图像组合成一个最终镜头的操作——在 Fusion 里，它通过节点树一层层叠加实现。

  • 层层叠加：每个 Merge 节点 把一层前景叠到背景上，多个 Merge 串起多图层。
  • 底图叫 Plate：视效行业把合成的基础素材称为 plate（底片），一切元素都叠在它上面。
  • 匹配才可信：透视、色彩一致性、噪点颗粒、景深、反光，任何一项对不上，观众就会出戏。
  • 只认一个出口：只有连到 MediaOut 节点 的结果才会送回剪辑页面。

操作步骤STEPS

  1. 在剪辑页面把播放头放到目标片段上，按 Shift-5 进入 Fusion 页面
  2. 把自动生成的 MediaIn 节点改名为 Plate（选中按 F2），它就是合成底图
  3. 从媒体池把第二个素材拖进节点编辑器，生成新的 MediaIn拖入第二个素材生成新的 MediaIn
  4. 添加 Merge 节点：Plate 接背景输入（橙色），新素材接前景输入（绿色）
  5. 把 Merge 输出连到 MediaOut，选中 MediaOut 按 1 或 2 载入查看器在查看器中检查合成结果
  6. 逐项检查透视、色彩、噪点是否匹配，回相应节点调整

练习PRACTICE

  1. 用一段实拍素材加一个 Text+ 标题做一次合成，回剪辑页面确认标题可见。
  2. 列出你的前景与底图在透视、色彩、噪点上的三处差异，标出打算用哪个节点修。

常见问题FAQ

合成和剪辑页面叠加视频轨有什么不同？

叠加轨道只是把画面叠上去；合成要进一步处理透视、色彩、噪点等匹配问题，节点能逐层精细控制。

怎么看合成的最终结果？

选中 MediaOut 节点按 1 或 2 载入查看器。没连到 MediaOut 的分支不会输出到其他页面。

我的合成看起来"假"，先查什么？

先查透视和色彩是否匹配，这两项最显眼；再查噪点颗粒与景深，逐项对照底图调整前景。

Learning Objectives学习目标

After this card you can explain what compositing is and build a believable composite with a "plate + layers + matching" mindset.

Concepts概念说明

Compositing is the craft of combining two or more images into one final shot — in Fusion, you do it by stacking layers in a node tree.

  • Layer by layer: each Merge Node composites one foreground over a background; chain Merges for more layers.
  • The base is the plate: VFX slang for the base footage of a composite — every other element is layered onto it.
  • Matching makes it believable: perspective, color consistency, grain/noise, depth of field, reflections — miss one and the audience notices.
  • One way out: only what reaches MediaOut Node is sent back to the edit page.

Steps操作步骤

  1. In the edit page, park the playhead over the target clip and press Shift-5 for the Fusion page
  2. Rename the auto-created MediaIn node to Plate (select it, press F2) — it's your base layer
  3. Drag a second clip from the Media Pool into the Node Editor to create another MediaInDragging in a second clip creates a new MediaIn
  4. Add a Merge node: Plate to the Background input (orange), the new clip to Foreground (green)
  5. Connect the Merge output to MediaOut, select MediaOut, and press 1 or 2 to load a viewerChecking the composite in a viewer
  6. Check perspective, color, and grain for a match, then adjust the relevant nodes

Practice练习

  1. Composite a Text+ title over real footage and confirm the title is visible back in the edit page.
  2. List three differences between your foreground and plate — perspective, color, grain — and note which node will fix each.

FAQ常见问题

How is compositing different from stacking video tracks in the edit page?

Stacked tracks just overlay pictures; compositing also solves matching problems like perspective, color, and grain, with per-layer node control.

How do I see the final composite?

Select the MediaOut node and press 1 or 2 to load it in a viewer. Anything not connected to MediaOut never leaves the Fusion page.

My composite looks fake — what do I check first?

Start with perspective and color — the most visible giveaways. Then check grain and depth of field, adjusting the foreground against the plate.

深度资料：合成 →Deep dive: 合成 →

本卡术语Terms in this card

媒体池Media Pool 编辑页Edit page 播放头Playhead 合成Compositing Fusion 合成Fusion 合并Merge 节点Node