In molecular modeling projects, visualization is not just an aesthetic choice—it’s a critical part of understanding, analyzing, and communicating your results. Whether you’re fine-tuning the lighting of a molecular scene for publication, or preparing complex renderings for a presentation, managing light nodes efficiently can save time and reduce frustration.
In SAMSON, lights are represented as a specific type of node that can be controlled through the light attribute space (li). This provides a structured and powerful way to filter and control visibility, selection, and even naming of your light nodes using the Node Specification Language (NSL).
Common Pain: Why Are My Lights Not Doing What I Want?
A frequent issue in molecular visualization workflows is difficulty determining what lights are active, hidden, or misconfigured. Did you accidentally hide a light source that was contributing to a render? Are multiple light nodes interfering with each other, causing unexpected shading? These problems are often the result of poor visibility or selection control.
This is where the light attributes in the NSL come in. SAMSON provides several inherited attributes specific to light nodes that allow users to filter, show, and manage these nodes with precision.
A Closer Look at Visibility and Selection
The following attributes are particularly helpful when dealing with light nodes:
li.h(hidden) – Determines whether a light node is hidden. You can find and toggle hidden light nodes using queries likenot li.h.li.v(visible) – Similar tohidden, but sometimes more intuitive. Want to list all visible lights? Useli.v true.li.selected– Lets you identify which light nodes are currently selected. Useful when editing a subset of lights.li.sf(selectionFlag) – Another selection-related flag. You can use it to exclude certain lights from selection operations.li.vf(visibilityFlag) – Controls whether a light should be visible based on global conditions, which is helpful when setting up flexible scene visibility states.
These attributes work in combination to offer powerful control. For example, to find all unselected but visible light nodes, you could use:
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li.v true and not li.selected |
Or, to isolate hidden lights that may need to be deleted or modified:
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li.h true |
When Naming Helps
li.n is another useful tool to search or group lights by custom names. For instance, if you named your key light "MainLight", you can target it specifically using:
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li.n "MainLight" |
Wildcards are supported too: li.n "L*" finds all lights beginning with “L”, some of which might be low-intensity fills or legacy lights you forgot to rename.
Conclusion
Efficient management of light nodes using NSL can significantly streamline your molecular visualization projects. By using visibility and selection attributes properly, you reduce guesswork and enhance control over scene lighting, leading to clearer, publication-ready molecular graphics.
To learn more, visit the official documentation page for light attributes in NSL.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at https://www.samson-connect.net.