Have you ever needed to illustrate a molecular mechanism that includes a clear visual spin or rotation between two states? Whether you’re preparing a presentation, teaching a concept, or documenting conformational changes between two poses, showing how a group of atoms rotates in space can provide essential context.
In many molecular modeling tools, animating such spatial transitions can be unintuitive or time-consuming. But in SAMSON, the Rotate animation makes this simple and precise: it allows you to rotate a selection of atoms or residues around their geometric center, with control over keyframes and easing.
Why Rotate?
Imagine this: you’re modeling a protein loop that swings open and shut, or visualizing how two fragments align during docking. A rotation might not be a physical trajectory, but it helps your colleagues grasp how parts relate spatially across states. This is particularly useful when comparing bound and unbound states, or presenting flexible motion in a protein domain.
The Rotate animation in SAMSON rotates a selected group of particles around their centroid, using the Z-axis as the rotation axis. The result is visually clean and easy to follow—perfect for movies, slides, and tutorials.
How to Create a Rotation in SAMSON
- Select the group of atoms or fragments you want to rotate. You can do this using SAMSON’s selection tools (see selection guide).
- Open the Animator and go to the Animation panel.
- Double-click on the Rotate animation effect.
- SAMSON will automatically insert the animation between the two keyframes you define. You can always move or modify the keyframes after insertion.
Controlling the Motion
The animation is performed between two keyframes. You control the duration (by adjusting the keyframes’ positions) and can shape the animation curve using easing options. For example, you might want the motion to start slow and accelerate, or vice versa.
To change the interpolation curve, go to the properties of the Rotate animation and adjust the Easing Curve. This helps you fine-tune the speed profile of the rotation, making your animations smoother and more natural-looking.
Note for Users of Earlier Versions
If you’ve used SAMSON before and remember using the Animation menu, you’ll notice it’s now integrated into the Animator panel. Access to all animations is streamlined here, and you can still use keyboard shortcuts if preferred (Ctrl+7 or Cmd+7).
Visual Example
Here’s an example of a simple Rotate animation applied to a molecular group:
Such animations bring clarity to which parts of a structure move relative to others and are especially helpful in collaborative or educational contexts.
To learn more about the Rotate animation and view detailed instructions, visit the official documentation page.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at https://www.samson-connect.net.