When a molecular trajectory plays, the part you want to inspect can drift toward the edge of the view—or out of it altogether. Repositioning the camera by hand can interrupt the animation and make it harder to compare motion. SAMSON’s Look at atoms animation offers a focused solution: it keeps the camera pointed toward selected atoms while leaving the camera’s position unchanged.
This is useful when you want to follow a region of a system through a trajectory but keep the same camera location. Think of it as changing where the camera looks, rather than moving the camera itself. The animation’s target follows the geometric center of the atoms selected when you create it.
Set up the view before adding the animation
First, select the atoms whose motion you want to keep in view. The selection matters: the target follows the geometric center of those atoms, so choose a group that represents the feature you care about. Selecting a region rather than the entire system can help keep attention on a local motion, while selecting a broader group makes the target follow a broader part of the structure.
Next, orient the view and camera to the position you want. The camera position you have at this point is used at the animation’s start and end frames. In the Animator’s Track view, choose the start frame, then double-click Look at atoms in the Animator’s Animation panel. Set the end frame to cover the interval you want to present.
Between those keyframes, the camera target moves with the selected atoms’ geometric center. The camera position does not change. This makes the effect useful for maintaining attention on moving atoms without introducing camera translation.
A simple way to avoid a common mismatch
If the camera follows the wrong part of the molecule, check the selection used when the animation was created. The target is based on those selected atoms—not on whichever atoms happen to seem visually important later. If you need a different region to guide the view, create the animation with that region selected.
Also distinguish between the target and the camera position. Look at atoms moves the target; it does not move the camera position along with the selected atoms. If you adjust camera positions with the animation controllers, the target remains at the geometric center of the specified atoms. You can change the animation’s start and end frames after creating it.
Check which camera the animation affects
By default, camera animations are applied to the active camera. If you need to change this, inspect the animation and adjust Apply to active camera. The animation’s target point is defined using the active camera’s current target position, which is essentially the current center of the view.
Camera positioning can also behave differently depending on whether the grid is on or off. To control whether that affects the animation, inspect it and review Keep camera upwards. These settings are worth checking when the result differs from the view you expected.
Use Look at atoms when the main challenge is keeping a moving region in view while preserving the camera’s position. For a different camera-following behavior, see the related Follow atoms animation. For the full instructions and properties, learn more in the Look at atoms documentation.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.