Guide images

A guide image is a plan, sketch or photograph you trace over. Calibrate it to a known length and it's to scale.

  1. Open References and its Underlays tab.
  2. Click the plus button (Upload scan or guide image) and pick a file: a .glb or .gltf scan, or a JPEG, PNG, WebP or GIF image up to 200 MB. An image becomes a guide on the current level at 50% opacity.
  3. Select the guide. Its panel has Replace, Delete, Show or Hide, and Lock or Unlock.
  4. Under Reference Scale, click Set Scale. Click both ends of a known distance on the plan.
  5. In Set overlay scale, enter the Real length and its unit (Metres, Centimetres, Feet or Inches).

On confirming, the image is resized and moved so the line you drew equals the length you typed. Quick Actions has Centre, Reset Rotation and Reset Image Scale, and Position, Rotation and Scale & Opacity sections give exact control. Each guide in the list has an eye toggle, a delete button and an Opacity slider.