A molecular presentation can look right at one moment and feel unexpectedly different after you scrub to another frame. Camera positions may have shifted while you edited the document; atom positions or visibility may not be defined where you expect them. These small inconsistencies can interrupt a scientific story just when you want the audience to focus on the structure.
A useful way to avoid surprises is to treat a presentation as a sequence of states. At important frames, make the molecular positions, camera view, and visible objects explicit. In SAMSON, you can build and preview that sequence in the Animator, where each animation appears as a track with keyframes.
Start with the story, then the tracks
Before adding effects, decide what the viewer should understand at each stage. For example: introduce the whole system, move in for a closer view, show a structural change, and finish with a clear view of the result. This simple outline helps you place effects intentionally instead of adding animations without a clear purpose.
Create a presentation through Visualization > Add > Presentation, or open the Animator and add animations from its Animation panel. Double-click a presentation in the Document view to edit it. The Track view shows animation tracks and keyframes, and lets you preview the presentation by choosing a frame directly.
Make molecular motion predictable
Motion animations can assemble or dock structures, move atoms, play trajectories, or create other molecular motion. A common source of uncertainty is what happens at frames where no motion animation is active. The documentation recommends using Hold atoms at frames where no other motion animation is being used for the relevant structural nodes. This is optional, but can help preserve the intended positions when you work in the document or switch between presentation frames.
Think of this as defining a stable starting point for the next part of the story. Add the motion you need, then consider where the structure should remain fixed. Preview the transitions by moving through the Track view, not only by watching the presentation play from beginning to end.
Give the camera a defined job
A carefully chosen molecular view can be lost if the camera changes while you edit. Camera animations include options such as Orbit camera, Move camera, Zoom camera, and Follow atoms. If you do not need a complex camera path at a particular point, the documentation suggests using Hold camera to define a static view. Preferably, specify a camera animation at each frame where you need the camera position to remain reliable.
Camera controllers appear in the viewport for supported animations and let you adjust positions, orientations, and target points. While editing camera positions, thumbnails for nearby keyframes can help you compare shots and keep framing consistent. If controllers are not visible, zooming out in the viewport may help.
Make visibility changes deliberate
Entrance, exit, and highlighting effects can progressively reveal or conceal nodes, change visibility, or adjust transparency. For example, Appear and Disappear affect nodes that have the transparency attribute, while Show and Hide change visibility at a frame. If a node should stay visible or hidden at a point where no other such effect applies, explicitly setting its state can help prevent unexpected results after editing or changing frames.
To add an effect, select the relevant node in the Document view, then double-click the animation in the Animator’s Animation panel. You can reposition keyframes in the Track view to change when the effect begins and ends. Animation order matters too: animations are applied in presentation order, and you can rearrange them by dragging nodes in the Document view.
Preview before exporting
Use the Animator controls or the Track view to inspect key moments: the opening frame, transitions, pauses, and ending. Check that the molecular position, camera, and visibility all match the intended story. If needed, adjust animation options in the Inspector. When the sequence is ready, use Save movie in the Animator and choose an available format, such as MP4, GIF, or WebM. Export behavior can depend on the global Presentation options.
This approach is useful whether you are preparing a short visual explanation or a longer presentation: define important states, make transitions purposeful, and review the result frame by frame before exporting.
For more details on the Animator, animation types, camera controllers, and movie export, see the SAMSON presenting and animating documentation.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.