A molecular scene can become difficult to follow when several structures, labels, or visual elements compete for attention. Hiding an object removes it immediately, which may make it harder for viewers to track what changed. A gradual fade offers a more legible alternative: the selected node becomes increasingly transparent, giving the audience a moment to follow the transition.
In SAMSON, the Disappear animation progressively fades nodes that have a transparency attribute. This includes structural models, visual models, meshes, and labels. It can be useful when preparing a presentation or recording in which you want to shift focus from one part of a scene to another without an abrupt cut.
Choose the right node before animating
The most important detail is what you select. Individual atoms and bonds do not have an opacity attribute; their structural models do. So, if the goal is to fade the visible representation of atoms and bonds, apply Disappear to the relevant structural model, rather than expecting to animate individual atoms or bonds directly.
This distinction can prevent a common presentation snag: adding an animation to the objects you can click most easily, then finding that the intended representation does not fade as expected. Before adding the effect, identify the node that owns the transparency you want to change. For other node types without a transparency attribute, Disappear behaves similarly to the Hide animation, rather than producing a gradual transparency change.
Use the four keyframes to shape the fade
To add the animation, first choose the nodes you want to fade. Then double-click Disappear in the Animation panel of the Animator. The effect has four keyframes, which define the transition:
- Between keyframes 1 and 2: the selected nodes remain fully opaque.
- Between keyframes 2 and 3: their transparency progressively increases.
- Between keyframes 3 and 4: the nodes remain fully transparent.
Those phases give you more control than a single instant change. The fully opaque portion can help establish the scene before the fade begins; the changing portion is the transition itself; and the transparent portion leaves the nodes faded out for the rest of that interval. You can move the keyframes to adjust when these phases occur. If the fade feels too sudden or too slow for the moment you are explaining, repositioning the keyframes is a practical place to start.
Make the transition easier to read
Consider what viewers need to notice while the model fades. If the animation is meant to direct attention to another part of the molecular scene, make sure that destination is already understandable when the fade begins. A gradual transition is most useful when it supports a clear change in focus—not when it asks the audience to interpret several changes at once.
You can also change how animation parameters are interpolated between frames by modifying the easing curve. Easing affects the progression between keyframes, so it offers another way to tune how the fade feels. Review the result in context: a fade that reads well in isolation may be harder to follow alongside other visual changes.
For a simple check, play through the animation and ask: does the intended model fade, do the other scene elements remain understandable, and is there enough time to see the transition? If the wrong elements change, revisit the node selection. If the fade itself needs adjustment, try moving the keyframes or changing the easing curve.
To learn more about the animation and its setup, see the SAMSON Disappear animation documentation.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.