Keeping Your Focus: Following Atom Groups Without Moving the Camera

When analyzing complex molecular systems, it is often necessary to track the movement of a specific group of atoms—perhaps a binding site, a ligand, or a key structural motif—during a simulation trajectory. However, rotating and translating the camera manually to follow such groups can be both time-consuming and imprecise, especially when creating animations for presentations, publications, or teaching materials.

In SAMSON, the integrative molecular design platform, there is a simple way to automate this behavior: the Look at atoms camera animation. This functionality continuously reorients your camera to follow the geometric center of the atoms you’ve selected, while keeping the camera position itself fixed. That means you’ll always be looking at your region of interest—no drifting, no manual tweaking.

Why This Solves a Real Pain

Molecular modelers often need to illustrate how a molecule (or a part of it) behaves dynamically—how a loop opens, how a ligand stays docked, or how a domain pivots. Yet, when preparing animations, the most common visualization issue is that the point of interest gradually moves out of view as atoms change position over time.

Re-adjusting the camera manually across keyframes introduces inconsistencies and can create jittery transitions. What modelers really want is to stay focused on the atoms, while still appreciating the broader movement of the molecular system.

Enter the Look at atoms animation effect.

How It Works

Here’s how to use it in SAMSON:

  1. Select the atoms you want the camera to look at—this could be any set of atoms you’re interested in tracking.
  2. Position the camera exactly where you want it to stay during the animation.
  3. Open the Animator’s Track view and choose your start frame.
  4. Double-click on Look at atoms in the Animation panel to apply the animation.

From that point on, as you advance the trajectory, the camera’s target point (i.e., the point it’s looking at) will shift automatically to follow the geometric center of those atoms. The camera maintains its position, giving you a smooth, stable view focused on what’s important.

Customization Options

You’re not stuck with a single camera perspective. You can:

  • Adjust the start and end frames for better timing.
  • Move the keyframes to fine-tune the animation without resetting your camera.
  • Inspect and change which camera the animation applies to (ideal if you’re using multiple cameras).
  • Toggle the Keep camera upwards option to choose between grid-based or free-camera orientation behavior.

These features combine to make sure your final animation looks intentional and polished.

Using the Right Tool for the Right Job

It’s worth noting that there’s also the Follow atoms animation, which moves both your camera and its target. That’s useful when you want a “molecular first-person perspective.” In contrast, Look at atoms is more neutral: it keeps you at a fixed distance but always looking where you need to.

Here’s an example to get a better sense of what it looks like:

Example: Look at atoms animation

To learn more and explore additional options, visit the original documentation page: https://documentation.samson-connect.net/users/latest/animations/look-at-atoms/

SAMSON and all SAMSON Extensions are free for non-commercial use. You can get SAMSON at https://www.samson-connect.net.

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