When analyzing molecular dynamics simulations or conformational transitions, it’s often just as important to watch a system evolve backward as forward. Whether you’re trying to study reversible processes, loop trajectories, or create smoother animations for presentations, being able to reverse playback can save time and provide valuable insight. Fortunately, the SAMSON integrative platform includes a simple, flexible way to do this: the Play reverse path animation.
This feature allows you to animate a molecule’s trajectory or path in reverse, between any two keyframes in your timeline. It’s particularly useful when you want to:
- Visualize reverse molecular motions such as folding/unfolding cycles
- Create bidirectional animation loops for clarity in presentations
- Synchronize multiple paths retracing the same steps
- Inspect reverse conformational changes
The way it works is straightforward: after selecting a path (or more), you can apply the Play reverse path animation from the Animation panel of the Animator. The animation proceeds from the end of the path back to the beginning. If you add multiple paths, SAMSON automatically synchronizes them.
How to Add It
1. Choose the moving object—typically a path node storing a trajectory.
2. Head over to the Animation panel and double-click Play reverse path.
3. Two keyframes are automatically created. Adjust them on your timeline to control the playback duration and interval.
4. You’re done: the motion will play in reverse between those keyframes.
Fine-Tuning the Reverse Playback
Reverse playback isn’t just about flipping direction. When the number of animation frames and path frames do not match, SAMSON automatically applies smoothing to the path. This may be helpful to produce fluid transitions, but you can always switch off smoothing in the Inspector, where additional adjustment options are offered.
In particular, the Easing curve defines how motion progresses between frames. This lets you choose whether motion appears constant, starts slow and speeds up, or follows any other interpolation behavior.
Used thoughtfully, these tools can help you create scientifically faithful and visually compelling representations of reverse molecular events.
Want to learn more? Visit the full documentation here: 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.