Tiles, layers, zoom, and 2D/3D presentation
Separate how map data is delivered from how it is grouped and displayed.
Why this matters
A world-scale map is too large to send all at once. Tiling lets an application fetch only the chunks needed for the current view, while layers keep different kinds of information understandable and controllable.
Learn it
A common web-map pyramid divides the world into tiles indexed by zoom, x, and y. Raster tiles contain rendered images; vector tiles contain vector features for client-side styling. Layers group or order content. A 2D record can be displayed with terrain, elevation, camera pitch, or extrusion without changing the identity of the underlying record.
Work through an example
A building footprint can remain the same polygon while a map shows it flat in 2D or extruded upward in a 3D presentation.
zoom z → 2^z tiles per axis
world tile count at z → 4^zPractice
- 1Change zoom in the tile exercise and observe how tile counts grow.
- 2Reorder layers and note how the visual result changes without changing the source features.
- 3Describe one case where 3D presentation adds understanding and one where it adds clutter.
Try it
Tiles, zoom, and layers
Tiles are a delivery and partitioning strategy, not a third data model. Raster tiles carry images; vector tiles carry vector features. Zoom levels divide the world into progressively smaller tiles.
At zoom z, a common web-map tile pyramid has 2^z tiles along each axis and 4^z tiles across the whole world.
What to watch for
Tiles are a delivery/partitioning mechanism. Layers are organizational or rendering concepts. Raster and vector are data models. Keep those ideas separate.
Where this takes you
These ideas matter when designing interactive maps, large datasets, terrain views, and applications that need fast map delivery.