Why serve scale-dependent imagery?

When the imagery is displayed on the map, the map scale determines which imagery sets are visible. Consider the example of a worldwide low-resolution data set that has a smaller image with a higher resolution on top. If users are viewing the map at a small scale, you want to display the low-resolution imagery. If the user increases the map scale by zooming in on a small area, you want to display the smaller, high-resolution image. To set up this switch, you may need to create a LuciadFusion Studio product that contains multiple sets of imagery.

Creating scale-dependent imagery in LuciadFusion Studio

The simplest approach is to add both images to the same product in LuciadFusion Studio. Just make sure that the higher-resolution image sits on top, so that it is not obscured by the world-wide image. Use the Move buttons on the details page of the product to specify the correct order.

Preventing the red hatching pattern on zoom-out

When users zoom out on the map, the red hatching pattern may appear, because the system takes precautions to prevent the loading of too much data.

If that happens for the world-wide imagery, it is best to use the approach outlined in Optimize data services by mixing coverages and native data.

If it happens for the smaller image, you can either use the same approach, or you can hide the image completely when the map is zoomed out, relying on the lower-resolution worldwide image. To do so, associate an appropriate styling definition with the image, such as the one in samples/resources/Data/LuciadFusionSLD/rasterOnlyWhenZoomedIn.sld. It defines a certain scale point for the display of data. For example, the data will be displayed from a scale point of 1:10.000. You may have to edit the SLD file to make it compatible with your situation.