A molecular model can be scientifically informative and still be difficult to read at first glance. When every part is visible from the start, viewers may not know where to focus. A gradual reveal can help guide attention: begin with a clear visual baseline, then let the selected nodes appear as the explanation reaches them.
In SAMSON, the Appear animation progressively reveals nodes that support transparency, such as structural models, visual models, meshes, and labels. It is useful when you want the audience to see a component emerge rather than simply switch from hidden to visible. The effect can also help make a presentation easier to follow by separating the act of introducing a structure from the details you discuss afterward.
Build a reveal around the point you want to make
Before adding the effect, decide which part of the model should become visible and when. For example, if your presentation discusses a particular structural model before its labels, you can select the relevant nodes and apply the animation to them as separate steps. This is a presentation-planning suggestion, not a special behavior of the animation: the key benefit is that you control which nodes receive the effect and can move the keyframes to fit your sequence.
To add it, select the nodes you want to reveal, then double-click Appear in the Animation panel of the Animator. The animation uses four keyframes:
- Keyframes 1–2: the selected nodes are fully transparent.
- Keyframes 2–3: they progressively appear as their transparency decreases.
- Keyframes 3–4: they remain fully opaque.
These stages give you a simple way to think about timing: an initial invisible interval, a transition, and a visible interval. Move the keyframes as needed so the reveal begins and ends at useful moments in your presentation. If the transition feels too abrupt or too gradual, SAMSON lets you change how parameters are interpolated between frames by modifying the easing curve.
Choose the right nodes
A common source of confusion is applying the effect to the wrong level of the model. Individual atoms and bonds do not have an opacity attribute; their structural models do. So, if your goal is to change the transparency of atoms and bonds, apply Appear to the structural models themselves. Nodes without a transparency attribute behave more like they do with the Show animation, rather than fading through changing transparency.
This distinction is useful when a reveal does not look like the gradual fade you expected. Check whether the selected node supports transparency, and, for atoms and bonds, check that you selected their structural model. Choosing the correct node is as important as arranging the timing.
Use the reveal to support—not replace—the explanation
A reveal works best when its timing matches what the audience needs to notice. Keep a node fully visible after introducing it if viewers need time to inspect it, and adjust the keyframes if the transition competes with your narration or other presentation actions. The animation does not decide what matters; it gives you a way to control when selected parts become visible.
The animation shown in the example uses an older Animation menu. In current SAMSON, access animations through the Animation panel in the Animator, and use the Animator’s controls for presentation actions.
For the complete instructions, see the Appear animation documentation.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.