In molecular modeling, analyzing a trajectory is often just as important as running it. But sometimes, we only realize what we’re looking for when we see it from an unexpected perspective — like watching the movement happen in reverse.
Whether you’re cycling between conformations, testing reversibility in a process, or simply visualizing the molecular journey backward for clarity, the Play reverse path animation in SAMSON makes it easy to walk your molecules back through their previous motions.
Why Play in Reverse?
Imagine you’ve created a conformational transition pathway or imported a dynamic trajectory. Watching the forward motion gives one perspective — but playing it in reverse can help:
- Spot subtle conformational toggles that happen as the structure returns.
- Better understand the hysteresis in conformational cycles.
- Create seamless looped animations of motions (forward and backward).
- Debug trajectory setups by comparing the forward and reverse flows visually.
How to Play a Path in Reverse in SAMSON
To reverse-play a molecular path in SAMSON, follow these steps:
- Select a path node. (You can use a path you’ve created or imported.)
- In the Animation panel inside the Animator, double-click on Play reverse path.
- This adds a reverse animation from one keyframe to another. You can freely move these keyframes to fit the time interval you want.
If multiple paths are selected, SAMSON synchronizes them automatically — a handy feature when you’re working with complex systems involving simultaneous transitions (e.g., protein subunits or drug-binding trajectories).
Smoothing Things Out (or Not)
If your animation has fewer keyframes than the original trajectory, SAMSON smooths the path by default. But maybe you want a raw, frame-by-frame rewind. That’s where the Inspector panel comes in.
From there, you can disable smoothing and ensure each original frame plays back exactly. This can be especially valuable when matching visualization with external frame-based data (e.g., time-stamped MD outputs).
Fine-Tuning Playback
You can further customize the animation behavior by adjusting its Easing curve. This alters how motion speeds up or slows down between frames, facilitating more natural-looking (or deliberately mechanical) trajectories for presentation or publication.
Who is This For?
If you’re a structural biologist visualizing conformational changes, a chemist presenting catalytic cycles, or someone teaching molecular behavior in an educational setting — reverse path animations can provide fresh insights and make your stories clearer and more engaging.
To learn more and explore reverse path animation options in detail, visit the official documentation page: https://documentation.samson-connect.net/users/latest/animations/play-reverse-path/
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at https://www.samson-connect.net.