When modeling molecular structures, clearly communicating spatial arrangements and transformations is essential. Whether preparing a teaching animation, capturing how molecules interact, or simply visualizing molecular conformations, one common need is to rotate a group of atoms to better convey a concept or result.
Visual clarity is not always guaranteed by a static image or an arbitrary camera move. This is where the Rotate animation in SAMSON can help. It allows you to smoothly rotate a selection of atoms or particles around their centroid, giving you control over molecular visualization while keeping focus centered where it matters.
Why centered rotation matters
Sometimes, rotating the entire view loosely around an object may not be enough. If you’re trying to demonstrate torsion, show relative movement, or inspect a particular group of atoms in stereo or repeated motion, you may want them to rotate precisely around a defined axis — in this case, the Z-axis passing through the group’s centroid.
For example, during a presentation, rotating a bound ligand around its geometric center can help highlight how it fits into a protein pocket. Or, you could be explaining a symmetry concept where a centered rotation provides exactly the insight needed.
How to use the Rotate animation in SAMSON
- Select the particles you wish to rotate. You can use SAMSON’s selection tools to define the group of atoms you’re interested in. Any selection will be rotated around its centroid, so choose carefully.
- Open the Animator. In SAMSON’s Animator, locate the Animation panel.
- Double-click “Rotate”. This inserts a Rotate animation effect associated with the currently selected group of atoms.
- Adjust the keyframes to control the timing and movement. You can freely move the keyframes to change how the rotation unfolds over time.
The rotation is always performed around the Z-axis passing through the group’s centroid, and automatic interpolation is applied between keyframes. The result is a smooth and predictable motion that’s especially helpful for producing consistent visual explanations or animations.
Customizing interpolation: the easing curve
To fine-tune the animation’s feel, you can modify the easing curve. This defines how the rotation progresses over time: constant speed (linear), starting slow and accelerating (ease-in), or any other interpolation shape. Easing control is particularly important for presentation — smoother transitions can increase visual comfort and enhance clarity.
What if you previously used the Animation menu?
If you’ve used older versions of SAMSON, you might remember the Animation menu. That menu has been simplified: now, use the Animator and its Animation panel to access all effects, including Rotate.
Here is a visual example of the Rotate animation in action:
This makes it intuitive to build smoother, more controlled animations, whether you’re building tutorials, preparing figures for publication, or setting up data exploration workflows within SAMSON.
Learn more in the original documentation: https://documentation.samson-connect.net/users/latest/animations/rotate/
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at https://www.samson-connect.net.