Geometry Overview & CAD Editing
Build and edit the slope cross-section with the on-canvas CAD geometry editor.
Build and edit the slope cross-section with the on-canvas CAD geometry editor. All model geometry is drawn directly on the canvas: you place and edit entities with the mouse, refine them with snapping aids, and type exact coordinates when precision matters.
Drawable entities
A model is assembled from the entities below. Each is drawn from the Geometry panel, and each has its own dedicated tools and clear command.
| Entity | Geometry | Purpose |
|---|---|---|
| External Boundary | Closed polyline | Defines the outer extent of the analysis domain. One per model. |
| Material Regions | Closed polylines | Partition the domain into regions, each assigned a material. |
| Water Table | Open polyline | Phreatic surface driving pore-water pressure. One per model. |
| Piezometric Lines | Open polylines | Named pressure lines (P1, P2, …) referenced per material. |
| Weak Layers | Open polylines | Thin seams with their own material that the slip surface can follow. |
| Tension Cracks | Closed polygon | Crest cracks, optionally water-filled, that clip the slip surface. |
| Anisotropic Surfaces | Open polylines | Constraint surfaces for surface-based anisotropy. |
| Anisotropic Vector Fields | Control polylines | Define local joint orientation for the Generalized Anisotropic model. |
| Ground Supports | Polylines | Reinforcement elements. |
| Block-Search Polyline | Polyline | Guide path for the non-circular block search. |
| User-Defined Slip Surface | Polyline | A single surface to analyze instead of searching. |
| Soil Profile Boundaries | Polylines | Visual reference only; not used in analysis. |
Soil profile boundaries
Soil profile boundaries are a drafting aid for laying out stratigraphy. They are rendered on the canvas but do not participate in the stability calculation. Convert them to material boundaries when you are ready to analyze.
Drawing an entity
Each entity type has a matching Add / Done pair of commands plus a Clear command in the Geometry panel.
- Click the Add command for the entity (for example, Draw Boundary or Add Weak Layer).
- Click on the canvas to place vertices, or type coordinates in the command input (see below).
- Click Done (or Close for closed shapes) to finish the entity.
To remove every entity of a type, use its Clear command (for example, Clear Material Boundaries or Clear Tension Cracks).
Command input (typed coordinates)
For precise geometry, type into the draw-command field instead of clicking. Two formats are accepted while a drawing tool is active:
| Format | Meaning | Example |
|---|---|---|
x,y | Absolute coordinate | 12.5,4 |
@length<angle | Relative polar offset from the previous vertex | @5<30 |
The polar form requires at least one existing vertex. The angle is in degrees, measured counter-clockwise from the positive X axis.
Editing geometry
Switch to Edit Vertices mode to modify existing geometry. The edit tools are:
| Tool | Action |
|---|---|
| Move Vertices | Drag a vertex to a new position. |
| Insert Vertex | Add a vertex on a segment. |
| Delete Vertex | Remove a vertex. |
| Move Boundary | Drag an entire entity. |
| Delete Boundary | Remove an entire entity. |
| Assign Material | Set the material of a region (see below). |
Editing exact coordinates
To set a vertex to an exact position, open the vertex editor, type the X and Y values, and apply. You can also edit coordinates in the Coordinates tab of the properties pane, which lists every vertex of the selected entity in an editable table.
Assigning materials
Right-click a region and choose Assign Material, then pick a material from the submenu. You can also use the Assign Material edit tool and click the target region.
Undo
Press Ctrl+Z (or Cmd+Z) to undo the most recent geometry change. History is retained for a limited number of steps.
Snapping
Snapping helps you place vertices precisely against existing geometry and reference lines. Each snap mode can be toggled independently:
| Snap mode | Snaps to |
|---|---|
| Vertex | Existing vertices. |
| Segment | Points along existing segments. |
| Orthogonal | Horizontal and vertical alignments from the previous vertex. |
| Grid | Grid intersections. |
An angle snap mode is also available; it snaps the current segment to a list of
preferred angles. The default angle list is 0, 5.71, 10, 20, 30, 37, 40, 42, 45, 65, 70, 80, 90 degrees. Edit it from the Snap Angles editor in the canvas status
bar by typing a comma-separated list of angles.
The grid spacing defaults to 1, and the grid can be shown or hidden independently of grid snapping.
Suppress snapping
Hold Alt while clicking to temporarily suppress all snapping for that placement.
Visibility and locking
Every entity carries independent visible and locked flags, toggled from the inspector layers sidebar. Hidden entities are not drawn; locked entities cannot be selected or edited until unlocked.