Assemblies

What you’ll learn

• Assembly tree: How the hierarchical Assemblies list reflects structure and names from your geometry file.
• Assembly names: How to select volumes and surfaces by name, including when the same name appears in multiple places.
• Assembly paths: How to select a specific instance using its full path from the root of the tree.
• Custom assembly paths: How to write path patterns with wildcards and attributes for flexible selection.

Imported CAD models often contain more than flat lists of volumes and surfaces. Parts are grouped into assemblies, sub-assemblies, and named bodies. Quanscient Allsolve reads this structure from the geometry file and shows it in the Assemblies tree.

Each leaf in the tree corresponds to a geometric entity (volume, surface, curve, or point). Like any other entity, it also has a numeric tag. The assembly tree gives you a second way to find and select entities: by the names and hierarchy defined in the CAD file, instead of by tag number alone.

This is especially useful when:

• The same part name appears many times (for example, repeated bolts or pads).
• You want selections to stay valid when tag numbers change but CAD names do not.
• You need to target a whole sub-assembly and everything inside it.

For background on tags and regions, see Regions.

Where to find the assembly tree

Assemblies are not available in projects that use the legacy Geometry Engine.

In the model view

When your project uses a geometry file with assembly metadata, the Common sidebar shows two lists:

1. Entities — flat lists of volumes, surfaces, curves, and points by tag (see Regions).
2. Assemblies — the hierarchical tree from the CAD files and other geometry objects.

In the Assemblies list you can:

• Click an item to select it in the model view.
• Hover over an item to highlight the corresponding geometry.
• Use the visibility control to hide or show volumes and surfaces (for groups, all hideable descendants are affected).

Folders represent assembly groups. Icons indicate entity types: volume, surface, curve, or point. Items without a name are shown with their entity tag.

In geometry operations

Geometry operations often require you to pick volumes, surfaces, or other entities as targets.

Use Pick with rule in Target. When assemblies are available, the picker includes an Assemblies tab alongside Entities, Text, and Range / Interval.

The Assemblies tab shows the same tree with checkboxes. Selected assemblies resolve to the underlying entity tags used elsewhere in the application.

Materials and physics

The Assemblies tab is not shown when you pick targets for materials or physics. To select by assembly names or other CAD attributes, create a Rule selector under Regions, and use the Attribute section in it’s settings. Then select that region as the target for the material or physics.

Assembly names and assembly paths

Names in the assembly tree come from the name property stored in the geometry file (for example, part or body names from a STEP import). In the application these are referred to as assembly names. They are not the same as entity tags: a tag is a number assigned by Allsolve; an assembly name is text from the CAD source.

There are two ways to select by name in the Assemblies tab.

Select by assembly name

With Select all matching names enabled (default), checking a node selects every tree node that has that name, anywhere in the model.

Example: if three bodies are all named Pad, selecting one Pad selects all three.

Use this when:

• Names are unique in your model.
• You intentionally want every instance of a repeated name.

Select by assembly path

With Select all matching names disabled, selection uses the full assembly path from the root of the tree down to the chosen node. Only that specific instance is selected.

The path is the sequence of assembly names joined from root to leaf, for example:

Assembly / SubAssembly / Pad

Use this when:

• The same name appears in multiple branches and you need one specific instance.
• You want selections to be unambiguous.

Path vs name

If Bolt appears under both Engine and Chassis, select by name to get every bolt, or disable Select all matching names and select Engine / Bolt or Chassis / Bolt to get one branch only.

Selecting a group

When you select a group (folder) in the tree, all geometric entities under that group are included — volumes, surfaces, and other allowed types within that subtree.

Child nodes may appear checked or marked as already included even if you did not click them directly. Hover the info icon on such a node to see which parent selection or path caused it to be included.

Custom assembly paths

The Text tab in the pick with rule tool supports Custom assembly path patterns. These go beyond clicking the tree: you can match many nodes at once using wildcards and attributes.

Switch to Text, choose Assembly path, and enter a path in the input field. Segments are separated by /.

Path syntax

Segment	Meaning
PartName	Matches a node whose assembly name equals PartName.
*	Matches exactly one level in the tree (any name at that depth).
**	Matches zero or more levels at any depth.
key=value	Matches a node that has the given attribute from the geometry file. Plain names are treated as name=PartName.

Examples:

Path	Selects
Engine / Cylinder_1	The node named Cylinder_1 directly under Engine.
**/Bolt_M8	Every node named Bolt_M8, at any depth.
Engine_V6/**/Bolt_M8	Every Bolt_M8 under the Engine_V6 subtree.
Layer=2	Nodes with attribute Layer equal to 2 (when defined in the geometry file).

After entering a path, click Add. Added paths appear as chips and can be edited or removed.

Wildcards

The segment ** cannot be placed directly next to another wildcard (* or **). Invalid patterns are rejected with an error message.

Attributes from the geometry file

Besides the name attribute, CAD files can carry other metadata (material labels, layer IDs, custom properties). These appear as attributes on entities in the entity tree.

In a custom assembly path, match them with attributeName=attributeValue. The name attribute corresponds to the assembly name shown in the tree.

Attribute-based selection is also available in the Attribute section when creating a region rule.

Comparison with other picking methods

Method	Best for
Assemblies (name)	Repeated parts sharing one name; CAD-driven workflows
Assemblies (path)	One specific instance when names repeat
Custom assembly path	Bulk selection with wildcards or attributes
Entities	Picking by tag when names are missing or irrelevant
Range / Interval	Sequential tag ranges
Text → Tag ID	Typing tag lists such as 1, 3, 5-10
Model view	Visual picking of visible geometry

Assembly-based selections are stored as names or paths. They are resolved to entity tags when the model is built, so they can remain stable across geometry changes that preserve CAD naming — unlike raw tag numbers, which can change when the geometry stack changes (see Working with geometries).

Practical workflow

1. Import or build a geometry and click Confirm model changes.
2. Open the Assemblies list in the Common sidebar to inspect names and hierarchy from your CAD file.
3. When defining a geometry operation target, open the Pick with rule tool → Assemblies. For materials and physics, create a region rule first (see the note above).
4. Choose Select all matching names on or off depending on whether names are unique.
5. Check the assemblies or entities you need; use visibility controls to isolate parts if the model is crowded.
6. For complex patterns, use Text → Assembly path with wildcards or attributes.

Unnamed nodes

Nodes labeled Unnamed do not have a name attribute from the geometry file. They cannot be selected by assembly name or path in the Assemblies tab, but can still be selected by tag in the Entities tab or in the model view.

Related topics

• Regions — entity tags, regions, and tag-based picking
• Working with geometries — geometry editing and when entity tags are locked
• STEP files — importing CAD files that carry assembly metadata