When building a molecular scene in SAMSON, lighting plays a key role in making sure that your visualizations are both scientifically clear and aesthetically compelling. But if your project involves multiple light nodes—think of directional lights, spotlights, or ambient light sources—it can be difficult to keep track of what’s turned on, what’s visible, or even which one is which. This blog post explores how you can use the light attribute space in SAMSON’s Node Specification Language (NSL) to efficiently select, filter, and organize light nodes in your molecular design.
Why This Matters
In molecular modeling, visual clarity is essential. Whether you’re preparing publication-quality figures, aligning structural features, or analyzing systems under varying illumination, knowing which lights are active and how to manage them efficiently saves time and reduces errors.
The Node Specification Language (NSL) provides a powerful way to query and manipulate objects in your scene. The light attribute space (abbreviated li) targets only lighting nodes, allowing fine-grained control over your light sources.
Quick Selection Examples
Using NSL, here are a few practical examples you can use to quickly manage your light sources:
- Find all visible light nodes:
li.v - Find all invisible light nodes:
not li.v - Select lights by partial name:
li.n "L*"— this selects all lights whose name begins with ‘L’ - Hide all selected light nodes:
li.selectedfollowed by settinghiddenattribute totrue
Understanding the Attributes
Light nodes inherit several attributes from the more general node attribute space. Here’s a quick guide:
| Attribute | Short Name | Meaning |
|---|---|---|
hidden |
h |
Whether the light node is hidden (not displayed) |
name |
n |
The string name of the light node |
visible |
v |
If true, the light contributes to the rendering |
selectionFlag |
sf |
Indicates selection status, can be used for toggles |
visibilityFlag |
vf |
Controls conditional visibility based on scene state |
selected |
(no short name) | If the node is currently selected |
Helpful Tips
- Use quotes for names, e.g.
li.n "MainLight" - Combine filters to narrow down queries, e.g.
li.vf true and not li.h - If you’re experimenting with light setups, toggle
li.vto quickly test shadow combinations
Use Case: Cleaning Up Lighting Before Export
Before exporting a figure or animation, it’s useful to make sure only relevant light sources are active. A quick query like not li.v allows you to review disabled lights and decide what to remove or reactivate. Similarly, li.selected can help you apply batch settings such as hiding or renaming.
Mastering these simple NSL expressions can help streamline your scene organization and let you focus on designing compelling molecular models.
To explore the full documentation, visit Light attribute space in NSL.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can get SAMSON at https://www.samson-connect.net.