Drafting Aids

Drafting aids are helpers that guide where your points land. Left to itself, a mouse click lands wherever your hand was. With these on, the program nudges each point onto a straight line, a tidy angle, a regular spacing, or an exact spot on existing geometry.

There are five, each a button on the status bar along the bottom. Each applies to every drawing, and each is remembered the next time you open the program. A button that is on has an outline round it.

Three of them have a small arrow beside the button that opens their settings: beside Polar, the angle step; beside Grid, the spacing and whether the grid is shown; beside Snap, which kinds of point it catches.

Prerequisites

• You can draw a line — see Drawing Basic Shapes.

Ortho — F8

What it does. Forces every point to be straight across or straight up and down from the previous one. Ortho is short for orthogonal, which means "at right angles".

Why you want it. With Ortho on, drawing a rectangular floor plan becomes: point roughly in a direction, type a length, press Enter. You never aim carefully, and the corners come out exactly square.

The escape hatch. Hold Shift to flip Ortho for that moment — off if it is on, on if it is off. That is how you draw the one diagonal line in an otherwise square drawing, without pressing F8 twice and forgetting to turn it back on.

Polar — F10

What it does. Holds the direction to steps of an angle as you move near one — every 15° unless you pick a different step from the arrow beside the button.

What you will see. A small label names the angle as you draw, so you can tell that you really are on 45° and not on 44.8°.

Ortho and Polar take turns

Turning one on turns the other off. They answer the same question — "which directions am I allowed?" — so Pingendum will not let them disagree.

In effect, Ortho is Polar locked to 90°. Use Polar when your drawing has angles in it; use Ortho when everything is square.

Grid and Grid Snap

These two get confused constantly, because the names are similar and the buttons sit together. They are separate things:

• The grid (F7, or Ctrl+') is what you see — a background of lines, there as a visual reference. View ▸ Grid shows or hides it.
• Grid Snap (F9) is what the cursor does — your points land on steps of a spacing.

They work independently. You can snap to a grid you cannot see, or look at a grid while placing points freely wherever you like. Turning the grid on does not make anything snap, and turning snapping on does not make the grid appear.

Both the spacing and the grid's visibility are set from the arrow beside the Grid button, and also in Preferences ▸ Canvas.

Snap and Snap Tracking

These two are big enough to have a chapter of their own: Precision Object Snaps covers the ten kinds of point you can catch, how to ask for one by name for a single pick, and how to line up with points without drawing anything.

In short: Snap catches exact points on existing geometry, and Snap Tracking draws temporary guides out from points you pause on.

What wins when they disagree

With several aids on at once, something has to decide. The order is fixed, and worth remembering:

1. A typed point beats everything. 1200,400 goes to 1200,400, full stop.
2. An object snap beats Ortho and Polar, so your point lands on real geometry rather than on a tidy angle.
3. Ortho or Polar decide the direction when no snap is within reach.
4. Grid Snap applies when nothing else has claimed the point.

Isometric drafting

What isometric means. A way of drawing a 3D-looking picture on flat paper, with nothing drawn in true perspective: vertical lines stay vertical, and everything else runs at 30°. Pipework diagrams and assembly drawings use it constantly.

View ▸ Isometric Drafting switches the whole drawing into that mode:

• The grid changes to lines at 30°, 90° and 150°.
• Grid snap goes to where those lines cross.
• Ortho now holds the current plane's two directions instead of horizontal and vertical.

Unlike the five aids above, this one is the drawing's own setting — it is a single undo step, and it is saved in the file.

The isometric plane

An isometric drawing has three faces — think of looking at the corner of a box. F5 (on macOS, ⌥⌘I too) steps between them: left, top, right. The status bar says which one you are on.

Everything then follows that face: Ortho's two directions, and two tools in particular.

• Ellipse ▸ Isocircle (I) draws what a circle looks like on the current face, from a centre and a radius. Constructing that by hand is genuinely tedious, so this is the tool that makes isometric work practical at all.
• Text ▸ Isometric writes text lying on the current face.

Drawing an isometric box

1. Choose View ▸ Isometric Drafting, and turn Ortho on (F8).
2. Press F5 until the status bar says the left plane. Draw the left face with Line, typing the lengths.
3. F5 to the right plane; draw the right face.
4. F5 to the top plane; draw the top.
5. For a hole on a face: F5 to that face, start Ellipse, press I, then give the centre and radius.

The video below shows the first part of that — switching isometric on from the View menu, and drawing one complete face on the top plane.

This is still a 2D drawing

Isometric drafting is a drawing convention, not 3D modelling. There is no solid, no camera and no model to spin round. What you have drawn is flat geometry that happens to be laid out at 30° so that it reads as three-dimensional.

Other view controls

These do not change where points land — they change what you are looking at.

User Origin is the one to remember for angled work. It moves and rotates the axes that coordinates are typed and reported in, so you can draw along a skewed wall with a plain @2400,0. See Typing Coordinates and Values.

Next Steps

Next: Selecting Objects