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Adding layers

Adding a layer is the routine entry point for any new feature group, and the flavor you pick at creation is the most consequential decision about the layer — it determines whether everything you add to it actually drives results. This lesson covers the flavor decision, the most common mistake it surfaces, and how layer removal works. For the click-by-click flow, see Layers → How to add a layer and Layers → How to manage a layer.

Learning objectives

By the end of this lesson you should be able to:

  • Distinguish QD-visible layers from background layers
  • Pick the correct flavor when adding a new layer
  • Recognize the symptom of a feature on the wrong layer flavor
  • Anticipate what a layer removal destroys, and choose hiding when removal is too aggressive

The two flavors​

Layers in Siter come in two flavors: QD-visible layers contain features the analysis engine evaluates, while background layers carry vector reference content (CAD line work, parcel boundaries, contour vectors, transportation overlays) that informs your siting but never participates in calculation. All Siter layers are vector — true raster imagery comes only via the built-in base-map switcher, not as a layer.

FlavorEngine reads it?Typical contents
QD-visibleYes — every feature on a QD-visible layer enters the analysis as either a PES or an ESMagazines, operating buildings, inhabited buildings, public routes, boundaries — anything that should produce or receive QD arcs
BackgroundNo — features on background layers are reference-onlyCAD polylines (often imported from .dwg), parcel boundaries, contour vectors, infrastructure lines (roads, fences) that does not bear QD itself

The two flavors are visually identical on the map by default. The distinction is purely about whether the feature participates in analysis.

Picking the flavor at creation​

When you add a new layer, set the flavor immediately. The flavor is harder to change later than the name or visibility, and a wrong-flavor layer that has accumulated features creates rework.

tip

If you need to change the flavor of an existing layer, you can export the layer (include attributes) and re-import as the other type.

The most common mistake​

A user adds a magazine to a background layer (often imported from a shapefile that landed on a background layer by default), runs analysis, and sees no QD arc for that facility. The feature looks complete — type code, attributes, explosives all entered — but it never appears in results.

The diagnostic is the Requires Analysis view. If a feature you expect to see in results is missing entirely (not even an error), check the layer flavor. Move the feature to a QD-visible layer (see Changing a feature's layer) and re-run.

What removing a layer destroys​

Removing a layer deletes it and every feature it contains. Analysis results referencing those features are invalidated; existing result sets and drawings that captured prior results stay intact but stop matching the live project.

tip

If you accidentally delete a layer you didn't mean to, hit Undo

Hide vs remove​

Reasons to hide instead of remove:

  • Features still need to drive analysis but should not appear on the map for the moment
  • You want to compare a "with" / "without" view by toggling visibility
  • The layer is vector reference data (CAD line work, contours) that may be useful later in the project

Hiding does not affect analysis — a hidden QD-visible layer's features still produce arcs and violations. It only changes what you see.

To exclude features from analysis without losing the data, move them to a background layer instead of removing them.

Try it​

Add a QD-visible layer and a background layer to a project. Add a PES with explosives to each, run analysis, and confirm:

  1. The PES on the QD-visible layer produces a QD arc
  2. The PES on the background layer produces nothing — no arc, no entry in results, no error message

This silent omission is exactly the failure mode the layer flavor protects against once you know to look for it.

Now hide the QD-visible layer and re-run; the arc should still appear in the results panel even though the feature is invisible on the map. Move the PES to the background layer (see Changing a feature's layer) and re-run; the arc disappears.