Naming and Selecting Cameras in SAMSON’s Node Specification Language

Molecular modelers working on complex simulations often need fine control over their visualization settings. One common hurdle is identifying and manipulating camera nodes precisely when scripting or setting up selections. In SAMSON, the Node Specification Language (NSL) provides a powerful way to interact with camera nodes, allowing you to search, filter, and automate tasks efficiently.

But here’s the challenge: if you use multiple cameras in a molecular design project — say one for a top-down protein view and another for ligand binding sites — how do you quickly distinguish and access them via scripting without clicking through the graphical interface?

This is where understanding camera attributes in NSL becomes useful. NSL enables camera-specific querying through the camera attribute space, abbreviated as ca. Let’s break down how you can streamline your workflow by mastering three key attributes: name, selected, and selectionFlag.

1. Naming Your Cameras for Easy Access

The ca.n attribute lets you identify camera nodes by name. Strings must be enclosed in double quotes, and wildcard naming helps if you follow naming conventions consistently. For instance:

This selects the camera node named “OverviewCamera.” Want all cameras starting with “L”? Try:

This can be especially handy when creating scripting workflows for different viewing perspectives.

2. Checking Camera Selection Status

The ca.selected attribute checks if a camera node is currently selected. This can be useful, for example, when exporting views or performing actions on active cameras during automation.

Note that ca.selected has no short name in this case. Being able to identify which camera is currently selected helps avoid accidentally running operations on the wrong viewport.

3. Using the Selection Flag

The ca.sf attribute (short for ca.selectionFlag) allows you to query the camera’s selection flag — useful in structured NSL queries or when handling many scene elements. Set it like so:

This returns cameras whose selection flag is enabled. It can often be paired with other attribute filters for deeper logical queries.

Tips for Better Project Organization

• Start using consistent names for your cameras (e.g., “LigandView”, “ActiveSiteView”).
• Use wildcards in ca.n "name* queries to process groups of related cameras.
• Check ca.selected in automated scripts to adapt behavior depending on user-selected views.

By mastering these attributes, you can start crafting accurate, contextual camera-related queries for better control in your molecular models. Whether you’re generating publication-ready figures or modeling dynamic simulations, a streamlined interaction with cameras makes a noticeable difference.

To learn more about camera attributes in NSL, visit the official documentation page: https://documentation.samson-connect.net/users/latest/nsl/camera/

SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at https://www.samson-connect.net.