Direct Modelling Commands in BricsCAD

Quick answer: Direct modelling commands create both solid and surface geometry, and are available in the Pro, BIM, Mechanical, and Ultimate licence levels. Octave’s documentation states that all of them carry a DM prefix, but several genuinely core direct modelling tools, EXTRUDE, REVOLVE, XFACES, ERASE, and UCS, don’t follow that pattern, worth knowing if you’re trying to identify one by name alone.

Creation Commands

Command	What it does
`EXTRUDE`	Creates 3D solids or surfaces by extruding open or closed 2D entities, faces of 3D solids, regions, or closed boundaries; can optionally add or remove volume from solids
`REVOLVE`	Creates 3D solids or surfaces by revolving open or closed 2D entities or regions about an axis
`DMTHICKEN`	Creates 3D solids by thickening surfaces, their faces, faces of 3D solids, regions, and wire entities
`DMCOPYFACES`	Copies a set of 3D solid faces forming a feature (a hole, rib, or protrusion, for example) to a new position on the same or another solid
`DMSTITCH`	Converts a set of region and surface entities bounding a watertight area into a single 3D solid

Modification Commands

Command	What it does
`DMCHAMFER`	Creates equal-distance or variable chamfers between adjacent faces sharing a sharp edge
`DMDEFORMCURVE`	Deforms connected faces of a solid or surface by replacing their edges with curves you specify
`DMDEFORMMOVE`	Deforms connected faces of a solid or surface by moving and rotating their edges
`DMDEFORMPOINT`	Deforms a region, connected faces, or a surface by moving a point on it in any 3D direction, deforming the affected faces as smoothly as possible
`DMFILLET`	Creates a smooth fillet between adjacent faces sharing a sharp edge
`DMPUSHPULL`	Adds or removes volume from a solid by moving or offsetting a face
`DMROTATE`	Rotates solids, faces, edges, or vertices around an axis
`DMTWIST`	Twists a portion of a solid, surface, or region, defined by two points, around an axis

Helper Commands

Command	What it does
`DMAUDIT`	Fixes inconsistencies in ACIS-kernel 3D geometry (solids and surfaces)
`DMAUDITALL`	Same as `DMAUDIT`, but also covers drawings inserted as external references
`DMGROUP`	Creates named, persistent collections of faces and edges from solids and surfaces
`DMSELECT`	Selects edges and faces based on their geometric properties
`DMSELECTEDGES`	Selects the edges of faces and solids specifically
`DMSIMPLIFY`	Simplifies a solid’s geometry and topology: removes unnecessary edges and vertices, merges seam edges, and replaces face and edge geometry with analytic surfaces and curves where possible, within a tolerance you set

Finding the Direct Modeling Tools

The Model tab of the Quad, when the cursor is over an entity or subentity, or a selection set exists.
The Direct Modeling menu.
The Direct Modeling, Fillet, Chamfer, and Deform toolbars.
The Home / Direct Modeling ribbon panel (Modeling workspace).

What Each Tool Applies To

Tool	Applies to
`DMPUSHPULL`	Any face of a 3D solid or surface
`DMMOVE`	Cylindrical, spherical, conical, and toroidal faces; linear and circular edges; whole solids, surfaces, and other entities
`DMROTATE`	Planar, cylindrical, spherical, conical, and toroidal faces; whole solids, surfaces, and other entities
`DMSIMPLIFY`	3D solids, surfaces, and their faces
`DMSTITCH`	Surfaces
`DMAUDIT`	3D solids and surfaces
`UCS` (Face option)	Planar faces of solids and surfaces. When Dynamic UCS is on, the UCS aligns automatically to whichever solid face is under the cursor, with the icon updating accordingly
`EXTRUDE` (Solid mode)	Closed 2D entities and detected closed boundaries (auto-detected if the “Select detected boundaries” option of `SELECTIONMODES` is on); planar faces of solids and surfaces; closed 2D entities and boundaries on a solid’s planar face
`REVOLVE` (Solid mode)	Closed 2D entities and detected closed boundaries; planar faces of solids and surfaces; closed 2D entities and boundaries on a solid’s planar face
`XFACES` (Extract Faces)	Surfaces and faces of 3D solids
`DMCOPYFACES`	A set of 3D solid faces
`DMTHICKEN`	Faces of solids and surfaces; surfaces; wire entities (lines, polylines, circles, ellipses, arcs, helices, and splines)
`DMFILLET` (Constant radius)	Sharp edges of a solid or surface
`DMFILLET` (Variable radius)	Sharp edges of a solid or surface
`DMCHAMFER`	Sharp edges of a solid or surface
`DMCHAMFER` (Advanced mode: constant asymmetrical, constant angular, variable symmetrical, variable asymmetrical, variable angular)	Sharp edges of a solid or surface
`ERASE`	Faces of a solid or surface; whole solids and surfaces; free edges of a surface (an edge with only one adjacent face); edges between coplanar faces
`EXTRUDE` (Surface mode)	2D linear entities and edges of solids and surfaces
`REVOLVE` (Surface mode)	2D linear entities and edges of solids and surfaces
`DMDEFORMPOINT`	Faces of a solid or surface
`DMDEFORMMOVE`	Edges of a solid or surface
`DMDEFORMCURVE`	Edges of a solid or surface
`DMTWIST`	Solids, surfaces, or regions

Frequently Asked Questions

Do all direct modelling commands actually start with “DM”? Not quite. While most do, EXTRUDE, REVOLVE, XFACES, ERASE, and UCS are all core direct modelling tools without that prefix.

Which licence levels include direct modelling commands? Pro, BIM, Mechanical, and Ultimate.

What counts as a “free” edge for the ERASE command? An edge on a surface with only one adjacent face, as opposed to an edge shared between two faces.

How does Dynamic UCS interact with the UCS Face option here? When Dynamic UCS is on, the UCS aligns automatically to whichever solid face is under your cursor, and the UCS icon updates to match.