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Layers

Layer management

Nullcad has a robust layer management system. There are 3 types of layers available to the user:

  • Standard Layer
  • Layer Group
  • WMS Layer Pro

Layer properties

Standard layers have:

  • Visibility — Hide or show all geometry on the layer
  • Lock state — locked layers can’t be edited or selected
  • Label visibility — see Annotations & Labels
  • Colour — Set the colour of the layer’s geometry, the full ACI palette is available or pick from a custom RGB value
  • Name — You can use any layer name you like, it is not required that layers have unique names, nullcad stores a unique identifier for each layer under the hood.
  • Line weight — Set the line weight of all geometry on this layer. Uses the CAD standard millimetre denominations.
  • Line type — Set the line type of all the geometry on this layer. Select from built in or custom line types.
  • Delete button — Remove the layer. If the layer contains geometry you will be asked if you want to move the geometry or delete it along with the layer.

Phase-based filtering

Geometry is tagged with the survey phase it was created in (see Survey Phases), and the canvas filters what’s shown accordingly — you generally only see geometry relevant to the current phase, plus anything explicitly composed into a Drafting viewport.

WMS Layer

Pro Feature

WMS Layers allow for background maps to be displayed easily behind geometry. You can manage templates from View -> WMS Templates where you can set the properties of a WMS template, save and edit existing templates.

To add a template WMS layer to the canvas you must have a CRS set in File -> Document Properties to allow the system to understand the required transformation to apply to the fetched tiles.

Transformations are applied on the fly through proj4. It is not necessarily the most robust transformation and so should not be relied upon for survey data.

Fetched tiles are stored in an on-disk cache to speed up viewing and limit the amount of bandwidth use. If you need to clear the cache from stale data you can press the Clear Cache button at the bottom of the WMS Templates window.