B-roll
你可以通过在右侧边栏添加 bRoll 元素，将额外的视频或照片素材叠加到你录制的场景上。
🌐 You can overlay your recorded scenes with additional video or photo footage by adding bRoll elements in the right sidebar.
将你想使用的素材添加到 public 文件夹中，然后在你想要覆盖的场景的 bRoll 下拉菜单中选择它。
🌐 Add the footage you want to use to the public folder and select it from the bRoll drop-down menu for the scene you want to overlay.
通过调整 from 和 durationInFrames 值来配置何时以及播放资源的持续时间。
from 值是相对于你添加 B-roll 的场景，并定义资源要显示的帧。
🌐 Configure when and for how long to play an asset by adjusting the from and durationInFrames values.
The from value is relative to the scene to which you are adding the B-roll and defines the frame from which the asset is to be displayed.
约束
🌐 Constraints
你在 bRoll 中添加的数据会经过后处理，以执行以下规则：
🌐 The data that you add in bRoll is postprocessed to enforce the following rules:
- 如果第二个B-Roll覆盖第一个B-Roll，第一个B-Roll可能在第二个B-Roll消失之前不会消失。
- 在过渡到下一个场景之前，B卷必须已经消失。
这些约束在 remotion/scenes/BRoll/apply-b-roll-rules.ts 中定义。
🌐 These constraints are defined in remotion/scenes/BRoll/apply-b-roll-rules.ts.