Rotating a group of atoms in a molecular model isn’t just about aesthetics—it can be key to understanding symmetry, motion, and interactions in structures. Whether you’re preparing a presentation, validating behavior, or identifying geometric patterns, cleanly rotating a system around its center is often necessary. But how do you do this efficiently and precisely?
If you’re using SAMSON, there’s a built-in Rotate animation that can help, especially in creating intuitive and informative molecular animations. Here’s what it offers and how it resolves a common modeling pain point: animating molecular rotation without having to manually adjust each frame.
Why rotate atoms around the centroid?
When visualizing molecules, we often want to showcase interactions and alignments between atoms or subunits. A simple rotation around the molecule’s centroid (the average position of its atoms) helps in getting a 360° view without changing the relative positions or losing spatial context. Doing this by hand is tedious and imprecise. SAMSON’s Rotate animation automates this in seconds.
How it works
The Rotate animation in SAMSON is designed to rotate a selected set of atoms or particles around their geometric center, following a vector aligned with the Z-axis. This gives a smooth and systematic rotational effect that can be easily controlled between two keyframes.
To use the Rotate animation:
- Select the group of particles you want to rotate. You can learn more about selection in this guide.
- Open the Animation panel within the Animator.
- Double-click the Rotate animation effect. This immediately creates an animation track for the selected group.
- Adjust the keyframes as needed to define the duration and begin/end rotation states.
You can customize the interpolation of rotation by adjusting the Easing curve, giving you control over how the rotation accelerates and decelerates through time.
Bonus tips for smoother animations
- Use multiple Rotate animations on different groups to create layered motion effects.
- Combine with the Rock or Move atoms animations for more complex molecular behavior.
- If you’re preparing a video, keep note that the Animation menu shown in older tutorials is no longer present. Now everything runs through the Animator’s Animation panel.
SAMSON makes the rotation animation process intuitive and reproducible—ideal for scientific presentations, teaching, or even checking structural geometry from different angles.
Learn more at the original documentation page for Rotate Animation.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at https://www.samson-connect.net.