A molecular scene can contain all the right structural information and still be difficult to read. Ribbons overlap, neighboring components blend together, and it becomes hard to tell which parts are closer to the viewer. This is a common visualization problem: the 3D structure is on screen, but the cues that help our eyes interpret depth are weak.
In SAMSON, three real-time rendering effects can help: ambient occlusion adds shading in less accessible regions, shadows clarify relative positions, and silhouettes outline regions at different depths. They solve related but different problems, so it is often more useful to adjust them deliberately than to switch on every effect at once.
Start with ambient occlusion
Ambient occlusion darkens areas that are less exposed to light, helping reveal depth within a molecular structure. In a dense view, this shading can make folds and neighboring parts easier to distinguish. SAMSON offers screen-space and object-space ambient occlusion. Screen-space ambient occlusion is efficient, though its appearance depends on camera distance; object-space ambient occlusion is more realistic but slower.
For a quick first test, switch on screen-space ambient occlusion from Visualization > Options. Compare the same view with the effect off and on before changing other settings. This makes it easier to see whether the extra shading clarifies the structure or simply makes the image darker.
Use shadows to understand placement
Ambient occlusion helps with depth within a structure; shadows are especially useful when you need to judge the position of one object relative to another. For example, a protein near a graphene sheet can be difficult to place visually if there are no shadows. Enabling shadows adds a cue that helps separate the objects and interpret their relative positions.
Shadows can be toggled in Visualization > Options, with more detailed controls in Preferences > Rendering > Shadows. If you are working with an older graphics card, the documentation recommends disabling shadows or choosing a lower preset. In practice, test the effect on your current view and system rather than assuming the highest setting is best.
Add silhouettes when boundaries disappear
When neighboring regions merge visually, silhouettes can make their separation clearer. They are particularly useful when you want to emphasize changes in depth without relying only on shading. You can toggle silhouettes in Visualization > Options and adjust their settings in Preferences > Rendering > Silhouettes. One documented example uses the Ribbons visual model for 1YRF with silhouette thickness set to 1.
A simple troubleshooting order
- Check the view first. Make sure the molecule and any neighboring structures are framed so their spatial relationship is visible.
- Try screen-space ambient occlusion. Look for improved depth in folds and closely packed regions.
- Enable shadows if the main difficulty is judging where separate objects sit relative to one another.
- Try silhouettes if boundaries between regions still blend together.
- Reassess after each change. Effects can reinforce one another, but a clearer view is not necessarily one with every option enabled.
For detailed parameters, open the Rendering section of Preferences. Quick switches and presets are available under Visualization > Options. For a broader guide to choosing visual models and visibility, see Visualizing. For final-quality offline images, use Rendering.
Read the SAMSON rendering effects documentation to learn more.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.