Draw and edit the alignment

What it does

The four commands on this page work on an alignment that is already defined — see the Alignment Manager for how one is created.

A word on terminology. CapCad keeps the distinction its Portuguese makes: the alignment (eixo) is the project's centre line, and an auxiliary alignment (alinhamento) is any other reference line stored beside it. That is why the Manager's button reads Auxiliary alignments….

Drawing the alignment

CAPCAD_ALIGNMENT_DRAW (shortcut EIXO) asks for nothing: it draws the whole active alignment.

• Each segment becomes a polyline on the layer the layer catalogue gives to the alignment (CAPCAD_EIXO-[type-]name in the default style), coloured by type — one-way carriageway = 1, two-way carriageway = 5, access = 93, edge = 4, highway = 2, untyped = 6 — with linetype SETA_CONT_1 at scale 20 and a constant width.
• Every drawn entity gets the DrawnAlignment xdata, and its handle is written back onto the segment. It is that handle the Reread from polyline button of the Alignment Manager uses later to re-read the edited geometry.
• The command line reports how many segments were drawn.
• With no alignment defined, the command asks Não há um eixo definido ou o mesmo é inválido. Favor checar em Gerenciador de Eixos. and offers to open the Alignment Manager there and then.

The sibling command CAPCAD_ROAD_KERB_DRAW does the same with the kerb curves stored on the alignment — left, right and auxiliary kerbs — each on its own style layer. If the alignment carries none of the three, it says so.

Auxiliary alignments

An auxiliary alignment is a curve stored as a property of the main alignment, with a name. That is how kerbs, offsets, right-of-way limits, access alignments and any other reference geometry travel with the project: they live in the .capcad file, not in the drawing.

The form opens even with no alignment defined — in that case the list shows only the three system entries.

The Auxiliary Alignments form (Portuguese render; the layout is identical in every language): the list of the defined ones on the left, the definition and the actions on the right.

Identifying the segment

CAPCAD_ALIGNMENT_SEGMENT_IDENTIFY asks for a point and looks, across the whole active alignment, for the segment (pair of vertices) whose perpendicular foot is nearest. When it finds one it:

1. draws a highlight — a polyline 15 units wide over that segment, on the non-plottable auxiliary layer;
2. shows a box with the segment's description;
3. erases the highlight as soon as you close the box.

The description gives the type (Line or Arc) and the length; for an arc, also the tangent angle at the end of the segment, the radius, the centre and the internal angle. Nothing found: Sub elemento não encontrado.

The command works on the segment, not on the alignment element: in a polyline with several vertices it isolates the stretch between two consecutive vertices.

Road cleaner: trim and break

CAPCAD_ALIGNMENT_TRIM_BREAK uses the alignment as a ruler to cut the drawing's entities over a stretch. It is the road-marking clean-up command: take the lines out of a stretch where an access comes in, break every line at a station, or erase everything outside a stretch.

The form is modeless and hides itself during the clicks.

Alignment tab in Trim mode: the two length boxes, Ext 1 and Ext 2, delimit the stretch. (Portuguese render; the layout is identical in every language.)

In Break mode, Ext 2 disappears, Ext 1 becomes a multi-line box — one station per line — and the "multi" notice (20) appears beside it.

Area tab: a single field, the offset of the area clip.

Util tab: send carriageway and shoulder to the back, now or after every command.

Tab 1: Alignment

Tab 2: Area

Tab 3: Util

Method, affected items and OK

How the options combine

The figures below come from the cut engine itself, run on four parallel lines and two clip points.

In Trim mode the stretch between the perpendicular feet of the two points is removed from each line (shown in light grey where it was), and the two ends remain. Note that the points need not lie on the entities: each one is cut at its own perpendicular foot.

In Trim mode with Inverse ticked, the same clip the other way round — only the middle survives.

In Break mode, a single point, and every open line becomes two independent pieces (blue and green). The geometry does not change; what changes is that there are now two entities.

Remembered between sessions

• The Road cleaner form saves its options on close, under the key FORM_LIMPA_VIA: method, affected items, layer filter, negative, the area offset and the Util-tab box come back as you left them.
• The exception is the alignment choice: an active alignment is always the default option when the form opens, whatever was saved. With no active alignment, Select takes over.
• The Auxiliary Alignments form saves no preferences.

Notes

• CAPCAD_ALIGNMENT_TRIM_BREAK opens with no alignment defined. The form always opens and the Active / Select rule sorts it out.
• The cut works by perpendicular foot on each entity, not by a straight cutting line. Entities that do not reach the stretch are left untouched.
• The multiple break (several stations in Ext 1, in Break mode) re-selects the whole model space for each station and shows a report at the end with OK or FAIL per line. On that path the on-screen check is skipped.
• Editing the polyline drawn by CAPCAD_ALIGNMENT_DRAW does not change the alignment: the alignment is the file. After editing, use Reread from polyline in the Alignment Manager.
• The system entries of the auxiliary-alignment list are recognisable by the capcad prefix in the name — which is what the form itself notes at the bottom.
• Undo (12) only covers the last Draw Selected (11) run; a Draw all (3) has to be undone with the CAD's own undo.
• The prompts and refusals of these commands (Selecione EIXO referência…, Provide value for point 1, Pontos input fora tela - enquadrando, Sub elemento não encontrado, Não definido, the filter and multi hints, and the no-alignment question) read the same in every language; they are quoted above as the software shows them.
• The keyboard alias BORDO is not available in this version; EIXO points at CAPCAD_ALIGNMENT_DRAW.

See also

• Alignment Manager — create the alignment, its segments and its stations.
• Alignment Tools — free chainage and the unifilar diagram.
• Alignment properties — the per-station values.
• Navigating the alignment — zoom, alignment and profile side by side, and driving the stretch.
• Station Navigator — go to a station and identify a point.