When navigating a map using the mouse wheel, the zoom sometimes stops at a scale slightly above or below the expected minimum or maximum limit (for example, stopping at 1:74 instead of the basemap's absolute minimum of 1:71).

This behavior is expected and is controlled by the Snap to Zoom setting, which determines how mouse wheel inputs are translated into map scale changes.

Depending on your application's needs, you can configure this behavior in the Web Designer by navigating to Map > Constraints and toggling the Snap to Zoom setting.

Snap to Zoom: OFF

With Snap to Zoom turned off, VertiGIS Studio Web allows for fluid, continuous zooming.

How it works: The map zooms in fluid increments that are determined by your operating system's mouse scroll speed settings, rather than the basemap's predefined scale levels.

The Advantage: You have the freedom to view the map at any custom scale. For example, if you want to view or manually type in a scale of exactly 1:500, the map will display at exactly that scale.

The Trade-off: Because the zoom operates in fluid mathematical increments rather than fixed steps, a mouse wheel scroll might calculate a final stop just short of the basemap's absolute lowest or highest scale limit (e.g., getting stuck at 1:74 instead of reaching 1:71). It also means that custom Min/Max Scale Constraints configured on the Map component may cut off slightly earlier than the exact number entered, depending on the scroll increment.

Snap to Zoom: ON

If you want to jump from one predefined scale level to another (including the Min and Max scale levels), you must enable the Snap to Zoom setting.

How it works: The map strictly locks to the predefined scale levels defined by your basemap.

The Advantage: Mouse wheel scrolling will always snap exactly to the predefined scales, guaranteeing that users can scroll all the way down to the absolute minimum scale (e.g., exactly 1:71) or maximum scale limit of the basemap.

The Trade-off: You lose the ability to view the map at custom scales between the defined LODs. If a user attempts to manually enter a custom scale like 1:500, the map will automatically snap to the nearest predefined level (for example, 1:564).

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