What Trace Opening Base does
Trace Opening Base is the shared superclass behind Trace Door, Trace Window, Trace Gate, and Trace Ventilator. It handles wall-pair snapping, width input, templates, and marker drawing. Each child tool only changes the label prefix, default width key, color, and template list.
Before you trace
- Turn on Trace tools in Settings (Trace > Enable Smart Trace). The tool will warn you and exit if tracing is disabled.
- Make sure wall edges exist on a recognized wall layer. The tool checks the layers listed in Settings, the Xpress3D trace wall tag, the 'Xpress3D-TraceWalls' layer, 'WAL', 'Layer0', and '0'.
- The tool operates on the ground plane (z = 0), so the traced wall plan should be flat on that plane.
- Markers are created on tool-specific trace layers: trace_doors, trace_windows, trace_gates, or trace_vents.
Setting the marker width
Each tool remembers its last width in the SketchUp configuration. Type a positive value into the VCB to set a custom width. Any length format accepted by LizArk works - 36, 3', 900mm, etc. The value is stored as the default for the current tool.
The effective width shown while tracing is multiplied by the trace scale multiplier when Manual scale mode is active in Settings.
Template widths
- Default window templates: 24" / 36" / 48" / 72".
- Templates are numbered 1-4 by order. Press 1, 2, 3, or 4 to jump to the matching template.
- Press / to cycle forward through templates.
- Each trace tool overrides the template list: doors, gates, and ventilators use their own common widths.
Placing a marker
Hover between two parallel wall edges. The tool searches for valid wall pairs and snaps a preview rectangle centered on the wall line.
The preview stops drawing when the cursor is farther than 24 inches from a wall edge. Move closer and try again.
Click to place: a center line is drawn across the wall pair, a text label is added (for example W36, D30, G96, or V24), and window/ventilator tools also draw a 2D opening symbol.
The normal direction points to the side of the wall pair you clicked on, which guides later 3D generation.
Marker labels and layers
Labels use a single-letter prefix followed by the rounded width: D for Door, W for Window, G for Gate, V for Ventilator.
Selection-role attributes are written on the marker entities so LizArk can select and process them during Generate 3D.
Keep markers on their assigned trace layers. Moving them off those layers can cause the 3D generation pass to skip them.
