When visualizing molecular systems and presenting dynamics to collaborators, students, or in publications, clarity and focus matter. One subtle yet powerful tool in the molecular modeler’s toolkit is the ability to rotate a selected group of particles around its geometric center, or centroid. This simple animation can significantly improve the way molecular interactions are perceived and understood.
In SAMSON, the integrative molecular design platform, the Rotate animation allows you to do precisely that. Unlike a global viewport rotation, this animation rotates only the selected particles, providing a focused and controlled view of specific parts of your molecular system. This can be ideal, for example, when you want to examine how a ligand fits into a binding site or explore the geometry of a ring system or a protein domain without changing the orientation of the rest of the structure.
Why Rotate Around the Centroid?
By rotating a group of particles around their centroid, you preserve the spatial relationships within the group while examining it from multiple angles. This is especially useful for:
- Studying conformational changes.
- Inspecting symmetry or chirality.
- Comparative analysis before and after simulations.
- Creating clean and instructive visual presentations.
The rotation is performed around a vertical axis (the Z-axis), centered on the selected group. This consistent frame of reference simplifies visual communications and avoids the distraction caused by rotating the entire scene.
How to Add the Rotate Animation in SAMSON
Here’s how to set up a Rotate animation in SAMSON:
- Select the group of particles you’d like to rotate by using the selection tools. For instance, select a protein domain or a side chain cluster.
- Go to the Animation panel inside the Animator.
- Double-click on the Rotate animation effect.
Your selected particles will now rotate between two keyframes. You can freely move these keyframes to define when the rotation starts and ends in your animation timeline.
Tips for Fine-Tuning
Adjust the easing curve: To change how the rotation accelerates or decelerates between frames, open the Rotate animation’s parameters and modify the Easing curve. This lets you create a smooth transition or a more dynamic spin, depending on your presentation needs.
Move keyframes with freedom: You can always adjust the timing by moving the keyframes. This allows you to synchronize the motion with other elements or narration in your video.
Note: You might come across older video tutorials that reference the Animation menu. It has been replaced with the Animation panel in the Animator, where all current animation features are now located.
Focused Rotation for Better Storytelling
Instead of rotating the entire model and potentially introducing unnecessary complexity into your scenes, the Rotate animation gives you precision. Whether you’re illustrating the behavior of molecular fragments or just creating visually engaging motion clips for presentations, this tool helps you stay focused where it matters—on the molecular region of interest.
To learn more about how to use the Rotate animation effect in SAMSON, visit the official 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.