When a molecular trajectory plays, a region of interest can drift toward the edge of the screen—or out of view altogether. One way to make that motion easier to follow is to move the camera’s target along with selected atoms while keeping the camera itself in place. In SAMSON, the Look at atoms animation is designed for this situation.
The distinction matters: this animation moves only the camera target point. It does not move the camera position. That makes it useful when you want to watch a selected part of a system travel or change during an animation without having the viewpoint follow it by changing position.
When this approach is useful
Imagine presenting a trajectory in which a particular group of atoms moves across a larger structure. A stationary target may leave that group off-center as the trajectory progresses. With Look at atoms, the target point follows the geometric center of the atoms selected when the animation was created. The camera continues to look toward that moving point, while its position remains unchanged.
This can help keep the visual focus on a region of interest. It is also a useful choice when you want the audience to retain the same camera viewpoint rather than watching the camera travel around the system. The animation does not change the molecular trajectory; it changes where the camera points during that trajectory.
Set it up before playback
- Select the atoms you want the camera to look at. The animation uses the atoms selected when it is created, so make the selection carefully.
- Orient the view and position the camera as you want it to appear. The current camera position is used for the animation’s start and end frames.
- In the Animator’s Track view, choose the start frame. In the Animator’s Animation panel, double-click Look at atoms.
- Set the end frame as needed. You can move the animation’s start and end frames later if the timing needs adjustment.
Between the two keyframes, the camera target moves with the geometric center of the specified atoms. Because the target follows the group’s center rather than a manually chosen atom, the point of focus can shift as the selected atoms move. This is worth keeping in mind when choosing a selection: the atoms should represent the region you want to keep in view.
Keep the camera behavior predictable
By default, camera animations apply to the active camera. If you need to change that behavior, 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.
The Keep camera upwards option is another setting to check if the camera behaves differently than expected. Camera positions can be defined differently depending on whether the grid is on or off. Inspecting the animation lets you control whether its behavior depends on the grid state through this option.
You can also adjust the camera position using the animation controllers. The target remains at the geometric center of the selected atoms, so camera-position adjustments do not replace the atom-following target behavior.
Look at atoms or follow atoms?
These similarly named animations solve different framing problems. Look at atoms moves the camera target while leaving the camera position unchanged. The related Follow atoms animation is worth considering when you want a different kind of camera motion. Choose based on whether you want to keep the viewpoint fixed or have the camera position follow along.
For the complete instructions and animation properties, see the Look at atoms documentation.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.