A molecular structure can be difficult to inspect when a view shows only one side of a group. A short rotation can help reveal its shape and make a presentation easier to follow. In SAMSON, the Rotate animation turns a selected group of particles around its geometric center, giving you a focused way to present that group without manually changing the structure’s position frame by frame.
What the Rotate animation does
Rotate animates the selected particles between two keyframes. The rotation axis passes through the group’s centroid and is collinear with the Z-axis. Because the center of rotation is the group’s geometric center, the selected group turns around its own center rather than orbiting around a point elsewhere in the scene.
That distinction matters when you want viewers to inspect a particular part of a molecular model. For example, a centered turn can help show different sides of a selected group in an explanatory animation. It is also useful when a static view makes the group’s arrangement hard to interpret.
A reliable setup
- Select the group first. Choose the particles you want to rotate. The selection defines the group for the animation, so take a moment to check that it includes the intended particles and excludes anything you want to remain outside the rotating group.
- Add Rotate from the Animator. In the Animator’s Animation panel, double-click the Rotate animation effect. The older Animation menu shown in some instructional material is no longer present; animations are accessed through this panel.
- Position the keyframes. The selected group rotates between the animation’s two keyframes. Move the keyframes as needed to place the motion in the part of your presentation where it will be useful.
- Review the transition. Watch the animation in context. If the change in motion between frames does not suit the presentation, adjust the easing curve, which controls how parameters are interpolated between frames.
Make the motion support the explanation
A rotation is most helpful when it answers a visual question. Before adding one, decide what a viewer should be able to notice: the arrangement of the selected group, a side that is hidden in the initial view, or how the group looks from more than one orientation. That goal can guide where you place the keyframes and how much time you leave for the motion.
Keep the selection and the animation’s purpose aligned. If the intended subject is a small group, rotating a much larger selection may make the motion harder to read. Conversely, a selection that is too narrow may omit the context needed to understand what is turning. Previewing the animation is a practical way to check whether the selected group reads clearly.
Also keep the axis in mind when planning the result: Rotate uses an axis through the selected group’s centroid that is aligned with the Z-axis. The documented effect is not an arbitrary-axis rotation tool. If the resulting orientation is not what you expected, first verify the selection and remember the axis definition before changing the timing or easing.
Use timing to improve readability
Keyframes determine when the selected group rotates, while the easing curve affects how the motion is interpolated between them. These are useful presentation choices, not just technical settings. A transition that is too abrupt may be difficult to follow; one that occupies a suitable portion of the presentation can give viewers time to observe the changing view. Adjust the keyframes and easing, then preview the result rather than assuming the default timing will fit every explanation.
Use the rotation to clarify the structure, not as motion for its own sake. A carefully selected group, a clear purpose, and well-placed keyframes can make a molecular view easier to inspect. Learn more in the Rotate animation documentation.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.