A mesh can be hard to track down when a scene contains many nodes: perhaps it is hidden, not visible, has an unexpected name, or simply is not the mesh you meant to inspect. SAMSON’s Node Specification Language (NSL) provides a compact way to describe mesh nodes using attributes such as name, visible, and selected.
This guide focuses on a useful first step in troubleshooting: narrowing your attention to meshes and checking the properties that can help explain what you are seeing. The expressions below are examples from the mesh attribute reference.
Start by keeping the search focused
Mesh attributes live in the mesh attribute space, whose short name is me. This space matches only mesh nodes. That makes me a useful prefix when your question is specifically about meshes rather than nodes in general.
For example, the expression me.n "A" uses the full attribute name name to look for a mesh named A. The reference also gives me.n "L*" as an example. When reading or writing an expression, the short name can make it more compact: me.n is the short form of me.name.
Check visibility-related attributes separately
The mesh reference lists three attributes that are especially relevant when investigating what appears in a scene:
visible, with short namev: examples includeme.vandnot me.v.hidden, with short nameh: examples includeme.handnot me.h.visibilityFlag, with short namevf: examples includeme.vfandme.vf false.
These are separate attributes in the reference, so it is useful not to treat their names as interchangeable. If you are unsure what a particular state means in your situation, follow the linked node-level definition for that attribute. The mesh page identifies these properties as inherited from the node attribute space.
A practical debugging habit is to check one condition at a time. For example, inspect me.v, then me.h, and then me.vf rather than assuming that a single visibility-related property explains the issue. This keeps the question precise and helps you distinguish which attribute you actually need to investigate.
Keep selection distinct from visibility
Selection is another useful property to check when the mesh you want is difficult to identify. The mesh attribute reference lists selected, with examples me.selected and not me.selected. It also lists selectionFlag, whose short name is sf, with examples me.sf and me.sf false.
One detail worth remembering: selected has no short name in the mesh attribute space. The reference specifically notes that it is inherited from node.selected without the node short name s. For clarity, use me.selected when expressing this mesh-specific query.
Check material-related properties too
If the question is whether a mesh has or owns a material, the reference provides hasMaterial (hm) and ownsMaterial (om). Examples include me.hm, not me.hm, and me.om. These attributes can help you frame a focused check without relying on the mesh name or appearance alone.
The main takeaway is simple: use me to keep the scope on meshes, then choose the attribute that matches the question—name, visibility, selection, or material. The short names are handy, but the full names can be easier to read while you are learning or reviewing an expression.
For the complete list of mesh attributes and their examples, see the SAMSON mesh attribute reference.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.