When analyzing molecular simulations, it’s often crucial to focus on a specific part of your system — a binding site, an interface, or a reactive center — as atoms move through time. But there’s a common frustration: if you want to keep your eye on a moving target, you usually end up rotating or translating the whole view, which can disrupt spatial orientation, especially in large systems.
This is where the Look at atoms animation in SAMSON can help. It offers a way to anchor your viewing direction to a group of atoms without changing the position of your camera. This prevents disorienting perspective shifts and allows for smoother and more informative animations of molecular motions.
Why fix the camera?
Changing the camera position constantly can make it harder to track movement or compare structural changes over frames. By contrast, keeping the camera in place while only adjusting its target (focus) allows viewers to perceive actual changes in the molecular system, not just in viewpoint.
How it works
With the Look at atoms animation, SAMSON sets the camera to continuously target the geometric center of atoms you initially select — for example, a ligand or a domain in a protein — while keeping the camera location static. This gives the effect of the viewer’s attention “locked onto” the selected atoms as they move.
To use this feature, follow these steps:
- Select the atoms you want the camera to focus on at all times.
- Align the camera the way you like – you can orbit, zoom, or pan to a good starting view.
- In the Animator’s Track view, choose your start frame and double-click on Look at atoms in the Animation panel.
- Set the appropriate end frame—this will define the duration of the focus tracking.
The camera will now track the motion of the selected atoms by adjusting only the target, not the position, resulting in a stable visual frame centered on the action.
When to use it
- Inspecting conformational changes while keeping your eyes on a specific molecule.
- Highlighting local movements without disorienting the viewer.
- Creating educational or presentation material where consistent framing is vital.
Controlling camera behavior
If needed, you can fine-tune the animation in the Inspector panel to:
- Control whether it applies to the active camera or a specific one.
- Decide whether the camera respects the scene’s up direction (based on the grid).
You may also manually adjust the camera position using animation controllers, but note that the camera will still look at the geometric center of the selected atoms.
See it in action
Consistent camera focus is a subtle but powerful tool for molecular modelers who need clarity when interpreting atomic-scale movement.
Learn more in the SAMSON documentation.
SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON here.