A molecular scene can contain all the right information and still be hard to read. At a glance, overlapping structures may seem to occupy the same space, edges can look jagged, and a dark background may hide important details. The useful fix is not always to change the molecular model or rearrange the scene: a few carefully chosen real-time rendering effects can make spatial relationships easier to see.
This guide focuses on a practical goal: improving depth and separation in an interactive molecular viewport without turning on every effect at once. In SAMSON, quick switches and presets are available from Visualization > Options. For more control, open Interface > Preferences > Rendering and adjust the settings for each effect.
Start with depth, not decoration
When a molecule looks flat, try ambient occlusion first. It darkens less accessible, deeper regions, adding a visual cue that can help distinguish parts of a structure. Screen-space ambient occlusion is a quick approximation and can be sensitive to camera distance; object-space ambient occlusion is more realistic but slower. For interactive work, screen-space ambient occlusion is often a useful first setting to test.
Compare the same view with the effect off and on. The difference is visible in this Ribbons representation of 1AF6:
As you compare, keep the camera position and zoom unchanged. That makes it easier to judge whether the effect improves depth perception or simply makes the scene darker. If you zoom substantially, reassess the result, since screen-space ambient occlusion is sensitive to camera distance.
Separate overlapping regions
For another depth cue, try silhouettes. Their outlines can help distinguish regions at different depths, especially in a Ribbons model. Enable silhouettes from Visualization > Options, or adjust their settings under Rendering > Silhouettes in Preferences. The documentation demonstrates 1YRF with silhouette thickness set to 1.
Shadows can help when the question is not just which parts overlap, but where one object sits relative to another. For example, shadows make the position of 1YRF relative to a graphene sheet behind it easier to perceive. If your graphics card is older, the lower shadow preset or disabling shadows may be preferable.
Keep edges readable
If the structure is spatially clear but its contours look jagged, adjust anti-aliasing. FXAA is described as an efficient option for many recent graphics cards. The example comparison uses multisampling set to 2 with FXAA enabled—the Higher quality preset—versus Best speed, which uses a multisampling factor of 1 and no FXAA. Smoother edges can improve readability, but anti-aliasing asks more of the GPU and may slow visualization for large systems.
A simple tuning order
- Choose a useful view first. Frame the molecular features you need to inspect.
- Test ambient occlusion. Compare on and off at the same camera position.
- Add silhouettes or shadows only if needed. Use silhouettes to separate regions; use shadows to clarify relative positions between objects.
- Finish with anti-aliasing. Choose a quality level that keeps the viewport responsive for your system.
These effects solve different readability problems, so a restrained combination is often easier to evaluate than enabling everything at once. If the result feels too dark or visually busy, switch effects off one by one and compare again.
For parameter details and more examples, see the SAMSON rendering effects documentation.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.