A crowded molecular scene is hard to work with when the property models you need are mixed in with many others. The first challenge is often not changing a model, but identifying the right nodes reliably. In SAMSON, the Node Specification Language (NSL) provides a way to describe property models using attributes such as name, visibility, and selection state.
This page focuses on the propertyModel attribute space, whose short name is pm. The key practical detail is that pm matches only property model nodes. That makes it a useful starting point when your search should be about property models rather than nodes of other kinds.
Start with a name or a state
If you know a model’s name, the name attribute is a natural first criterion. The documented examples are pm.n "A" and pm.n "L*". The short form n keeps expressions compact, while the full attribute name may be easier to read when you return to a query later.
Property models also inherit several boolean attributes from the general node attribute space. For example, pm.v checks the visible attribute, and not pm.v expresses its opposite. Similarly, pm.h and not pm.h refer to the hidden attribute. These examples are useful when you are trying to distinguish models by their displayed state, rather than by name alone.
Other documented boolean examples include pm.hm for hasMaterial, pm.om for ownsMaterial, and pm.vf false or pm.vf for visibilityFlag. The reference lists these as separate attributes. Treat them as separate criteria rather than assuming that similarly named attributes are interchangeable.
Keep selection and flags distinct
Selection-related attributes can be easy to confuse. The page lists selected and selectionFlag separately. For property models, selected has no short name, so its documented expressions use the full form: pm.selected and not pm.selected. By contrast, selectionFlag has the short name sf, with examples pm.sf and pm.sf false.
That distinction matters when you are reading or writing a query: pm.selected and pm.sf refer to different attributes in the reference. Don’t substitute one for the other just because both involve selection. If a query does not describe the set you intended, check the exact attribute name and whether the example uses a short name or the full name.
A small, dependable query routine
- Confirm the node type. Use the
pmattribute space when the target is a property model. - Choose one documented attribute. Start with a name, a visibility state, or a selection-related attribute that matches what you are looking for.
- Use the syntax shown for that attribute. Names take quoted strings in the examples; boolean attributes are shown with or without an explicit
false, depending on the example. - Check the result before refining. Keeping the criterion simple makes it easier to spot whether the attribute or the intended state needs adjustment.
This method helps avoid a common source of frustration: creating a complicated expression before confirming that each part means what you expect. The reference provides individual attribute examples, so build familiarity with those first. In particular, remember that visible and visibilityFlag are listed separately, just as selected and selectionFlag are.
For the full attribute list and inherited-attribute references, see the Property model attributes documentation.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.