Recently I worked on a shot that seemed simple on paper but turned into one of the most technically challenging composites of the project. Here's how I approached it.

The Setup

The shot featured an actor walking past a glass storefront. In the original plate, the reflection showed the film crew and equipment. We needed to replace the reflection with a clean street scene while maintaining all the realistic imperfections of the glass.

Initial Approach

My first instinct was to simply track in a replacement reflection. Quickly realized this wouldn't work because:

1. The glass had multiple panes at different angles 2. Each pane had different reflectivity and distortion 3. The actor partially occluded the reflection as they walked

The Solution

Step 1: Tracking and Rotoscoping

Created detailed tracks for each glass pane and rotoscoped the actor's interaction with the reflection. This took longer than expected but was essential for the final composite.

Step 2: Reflection Pass

Rather than using a single reflection plate, I created multiple passes: - Clean reflection footage shot at the correct angle - Distortion maps for each glass pane - Separate passes for each pane's unique characteristics

Step 3: Integration

The magic happened in Nuke:

```

Pseudo-code workflow

TrackedReflection -> STMap (distortion) -> Grade (reflectivity) -> Merge (over actor) ```

Applied different distortion and reflectivity values to each pane, maintaining the subtle imperfections of real glass.

Step 4: Final Polish

Added subtle aberrations, grain, and adjusted the color to match the slightly green tint of the actual glass. These small details made the shot feel photoreal.

Lessons Learned

1. Don't underestimate planning time - The tracking and setup took as long as the actual compositing 2. Reference is critical - Having high-quality reference of how glass actually behaves saved me multiple revisions 3. Break it down - Handling each pane separately was more work upfront but made the final result much better

Final Thoughts

Sometimes the most challenging shots are the ones that should be "simple." This project reinforced the importance of thoroughly analyzing a shot before diving in. ```