Navigation and the inference engine
SketchUp’s inference engine is its secret weapon: it snaps to axes, points and edges while you draw. Learn to navigate and use inference for accurate modelling.
In this lesson you will
- Orbit, pan and zoom fluently
- Read axis colours and inference cues
- Lock inferences with arrow keys and Shift
- Type exact lengths in the Measurements box
Navigation
Orbit: hold the mouse wheel and drag (or O). Pan: Shift + wheel drag (or H). Zoom: roll the wheel, or Zoom Extents (Shift+Z) to see everything. Use standard views (top, front) from the Camera menu, and switch to Parallel Projection for plan and elevation views without perspective.
Axes and colours
The red, green and blue axes are X, Y and Z. When your cursor moves parallel to an axis, the line turns that colour — red along X, green along Y, blue vertically. A magenta line means parallel or perpendicular to an edge. Black means no inference.
Point inferences
Coloured dots show points: green endpoint, cyan midpoint, red on edge, blue on face, black intersection. Hover over a point to 'wake' it, then move away along an axis to find a point aligned with it — like tracking in CAD.
Locking
Press an arrow key to lock a direction: right = red, left = green, up = blue, down = parallel/perpendicular to an edge. Or hold Shift to lock the current inference. Locking stops the line jumping to other snaps.
Typing values
After starting a line or a push/pull, just type a number and press Enter — it appears in the Measurements box. For rectangles type 4000,3000. You can type immediately after an operation to correct it. Set units in Window › Model Info › Units.
Quick reference
| Command / tool | How to start it | What it does |
|---|---|---|
| Orbit | O or wheel drag | Rotates the view |
| Pan | H or Shift+wheel | Moves the view |
| Zoom Extents | Shift+Z | Shows the whole model |
| Lock axis | Arrow keys | Locks inference direction |
Common mistakes
Lines go slightly off-axis.
Watch for the axis colour or lock with an arrow key.
Model seems to vanish when orbiting.
Zoom Extents; check for stray geometry far away.
Exercise
Accurate lines
- Draw a 5000 line along red by typing its length.
- From its midpoint, draw 3000 along green.
- Draw a vertical line 2700 up using the up arrow lock.
- Use a point inference to start a line aligned with an existing endpoint.
You should end up with: Precise lines drawn only with inferences and typed values.
Checklist
0 of 4 checked · saved on this device
Lesson quiz
A line turning green means it's parallel to…
Finished this lesson?
Taking the quiz marks it complete too. Your course page picks up where you stopped.
Free KitWren tools that help
- Length ConverterConvert between metres, centimetres, millimetres, kilometres, inches, feet, yards and miles.
- Area ConverterConvert square metres, square feet, acres, hectares and more.
- Image ResizerResize images to exact pixel dimensions or by percentage, keeping the proportions if you like.
- Image CompressorCompress JPG, PNG and WebP images to make them much smaller — with a before/after preview and the size saved.
- Paint CalculatorWork out how much paint you need for a room’s walls and ceiling, in litres or gallons.
- Flooring CalculatorCalculate how much flooring, timber, laminate or carpet to buy, including waste and boxes.
Free, independent learning material written for KitWren. SketchUp and LayOut are trademarks of Trimble Inc. KitWren is not affiliated with, sponsored or endorsed by Trimble. We never provide software downloads, licence keys or cracks — use the official sources.