Table of contents

Layer types

In PlexMap there are different layer types, which have influence on the kind of presentation and the loading behavior in the viewer. For example, there are layer types that can only be presented in the 3D viewer or only in the 2D viewer.

PlexMap always tries to find the appropriate Layer for a dataset when creating layers (this depends on the data type, but also on other factors such as the number of elements). However, for the PlexMap user, a basic understanding of layer types is helpful so that Views can be set up optimally (in terms of appearance, loading behavior, and performance).

The layer types are described below.

MapProxy (Raster data) Anchor

If a Layer of the type "mapproxy". is available, it provides rasterized 2D data. PlexMap uses the free software MapProxy for this purpose. MapProxy Layers can receive different data, these are e.g.:

  • Grid : Raster images (orthophotos, shading, shadowing, etc.) 
  • Feature : 2D features including style 
  • WMS : WMS services 
  • WMTS : WMTS services.

MapProxy Layers can also consist of combinations of the above mentioned types. For example, it is possible to overlay custom 2D features such as municipality boundaries on top of an existing WMS and create a Layer that contains both datasets rasterized.

All data passing through a MapProxy Layer is cached. This means that they are quickly available when the same tile is called up again and do not have to be queried again from the data source (i.e. WMS service, the database or the GeoTIFF file).

This cache is reset as soon as the Layer is saved again. This happens because the data can change when it is saved again.

Seeding

By "seeding" is meant the complete caching of an entire Layer. MapProxy is also functional without seeding, but the Seed MapProxy ensures that the individual tiles of a Layer can be delivered without delay.

Configure zoom levels Anchor

For MapProxy layers, display and loading zoom levels can be set in the layer settings.

The maximum loading zoom level defines until when a MapProxy layer is loaded. In this zoom level range data is actually reloaded. Normally, a layer should provide data up to at least loading zoom level 20 or 21.

The maximum display zoom level can be set differently from the loading zoom level. Example: A layer was created with loading zoom level 21. If the display zoom level for this layer is set to 24, users can still zoom up to level 24 in the viewer. Although no new data is loaded from zoom level 22 and the display becomes pixelated, a high display zoom level can be useful for measurements, for example.

The minimum loading zoom level defines from which zoom level data should be loaded. If the value is set to 0, data is always loaded. Setting higher values causes the layer to be displayed in the viewer only from a later zoom level. The behavior of the minimum display zoom level is identical. Thus, the minimum display and loading zoom level should be set to the same value.

 

Note: Defining high loading zoom levels is very memory intensive. So make sure you have enough disk space available and do not set loading zoom levels above 20 for layers that do not have high importance in the viewer.

zoom levels

2D features Anchor

A layer of the type "2D features", delivers 2D geometries. It can contain lines, points or polygons.

Since the 2D geometries are not optimized for WebViewing, the use of "2D Features" is only recommended for relatively small amounts of data.

If you want to publish larger amounts of 2D geometries with high performance, please use the "MapProxy" layer type for this purpose.

3D Tiles Anchor

A layer of type "3D Tiles" contains 3D geometries. For example, it can contain a 3D city model in CityGML format or a 3D mesh that is to be displayed in PlexMap 3D.

Technically, PlexMap uses the OGC standard 3D Tiles, which you can find more information about here.

The layer type "3D Tiles" is suitable for the representation of massive data sets on the Internet. In principle, you can store 3D datasets of any size in the "3D Tiles" layer type and publish them with PlexMap 3D.

Address Search Anchor

The layer type "Address Search", contains address data prepared for the address search in PlexMap. To learn how to correctly prepare address data for address search in PlexMap, see the tutorial "Address Search in Viewer".

Billboard (Cesium) Anchor

The layer type "Billboard (Cesium)", contains billboards for display in PlexMap 3D.

Billboards are, by definition, textured rectangles used in 3D computer graphics to simplify models. They are created by planar projection of the model to be simplified onto a rectangle.

Since this projection breaks down a model that may consist of several thousand polygons to just 2 polygons needed to represent the rectangle, billboards are of interest in the context of PlexMap 3D for performance-optimized web rendering of 3D symbols.

In PlexMap, billboards consist of the simplest possible symbol and a geo-coordinate at which the symbol is to be displayed. You can create billboards in the PlexMap Switchboard using the Billboards from 2D Objects function.

Billboard Tiles (Cesium) Anchor

Der Layertyp "Billboard Tiles (Cesium)“, enthält 3D-Texte zur Darstellung in PlexMap 3D (vgl. auch Beschreibung des Layertyps "Billboard (Cesium)“). 

In PlexMap bestehen "Billboard Tiles (Cesium)“ aus einem Text und einer Geokoordinate an der Ihr Text angezeigt werden soll. Sie können Billboards im PlexMap Switchboard über die Funktion 3D Text from 2D Objects erzeugen.

Files for Download Anchor

The "Files for Download" layer type lets you store any files that you want to make available for download through PlexMap.

You can create corresponding download layers in the PlexMap Switchboard using the Publish as Download function.

If your download consists of several files or is relatively large, it is recommended to compress the data beforehand via Zip.

External Terrain Anchor

Im Layertyp "External Terrain“ entspricht grundsätzlich dem Layertyp "Terrain Proxy" und wird eingesetzt, wenn Sie Digitale Geländemodelle (DGM) in PlexMap darstellen möchten. 

Allerdings wird das Terrain bei "External Terrain“ vorgeblich von einem externen Server geladen. Dieser "Trick" verbessert die Ladegeschwindigkeit Ihres Terrains in PlexMap 3D. 

"External Terrain“ kann also eingesetzt werden, wenn Sie ein extrem großes Terrain darstellen möchten.

External 3D Tiles Anchor

The layer type "External 3D Tiles" basically corresponds to the layer type "3D Tiles" and is used to display 3D models (e.g. CityGML or 3D Mesh) in PlexMap 3D.

External 3D Tiles" is used to load 3D tiles from an external server. Thus, "External 3D Tiles" is roughly comparable to a geo service for 3D data.

"External 3D Tiles" can thus be used to display 3D data provided in external software solutions in PlexMap.

Area search Anchor

The layer type "Area search" is used if a specific area is to be found as the result of an address search (e.g. all districts of a city).

Terrain Proxy Anchor

The layer type "Terrain Proxy" is used to prepare Digital Terrain Models (DTM) in PlexMap 3D. To learn how to prepare DTMs for web visualization with PlexMap 3D, click here.

Unlike "Terrain", the "Terrain Proxy" layer type can combine multiple DTMs with different resolutions into one viewer DTM layer (multi-resolution DTM).

Therefore, DTMs stored in "Terrain" are still slightly better optimized for web viewing than DTMs published via "Terrain Proxy".

Spherical panoramas Anchor

The layer type "Spherical panoramas" is used for the preparation of street view images for PlexMap Street360°. A layer of the type "Spherical panoramas" can contain the street panoramas and also possibly point clouds taken in parallel.

To learn how to display "spherical panoramas" in PlexMap 3D, please refer to the tutorial "Publishing 360° road traffic images".

Map Service Relay Anchor

The "Map Service Relay" layer type displays web services (OGC WMTS) from an external server in a PlexMap Viewer (e.g. PlexMap 2D or PlexMap 3D) without storing or caching the service or data of the service in PlexMap (services "looping through").

This can result in improved performance if the external server provides good performance, as external layers always offload the deployed PlexMap server.

The "Tour" layer type is used to store and publish flight tours in PlexMap 3D.  

To learn how to create flight tours with PlexMap, see the tutorial "Setting up POIs and flight tours".

Oblique aerial images Anchor

The layer type "Oblique aerial images" contains oblique aerial images for display in PlexMap Oblique. Learn how to prepare oblique aerial images for web visualization with PlexMap Oblique here.

Terrain Anchor

The layer type "Terrain" is used to prepare Digital Terrain Models (DTM) in PlexMap 3D. To learn how to prepare DTMs for web visualization with PlexMap 3D, click here.

Unlike "Terrain Proxy", the "Terrain" layer type cannot combine multiple DTMs with different resolutions into one viewer DTM layer (multi-resolution DTM).

For this, DTMs stored in "Terrain" are still slightly better optimized for WebViewing than "Terrain Proxy".

Universal JSON Anchor

The layer type "Universal JSON" is used internally by PlexMap to transfer and store sketches in the context of PlexMap Planner.

Users can publish sketches created in PlexMap Planner as layers for PlexMap 3D using Universal JSON. Compared to the layer type "3D Tiles", "Universal JSON" also supports special planner functions (such as cut-out polygons).

The "WFS" layer type provides a Web Feature Service (WFS) for PlexMap or for external viewers. WFS are fundamentally used to access vector data over the Internet, even if the data is on an external server.

The provided WFS service is loaded in PlexMap tiled. The loading behavior in external viewers depends on the individual configuration of the external viewer.

PMTiles Anchor

The layer type "PMTiles" offers the possibility of displaying vector data in PlexMap 2D in a high-performance manner using vector tiles.  

Vector tiles are packets of geographic data that are packaged into predefined, roughly square “tiles” for transmission over the Internet. As with the widely used raster tile web maps (Map Proxy layer type), the map data is requested by the viewer as a set of “tiles”. However, unlike web maps with raster tiles, the server returns vector map data cropped to the boundaries of each tile, rather than a pre-rendered map image.

In contrast to displaying vector data using the "Map Proxy" layer type, when using "PMTiles" your vector data is not rasterized but is actually displayed as a vector data set. This methodology enables very pleasant loading behavior of the data sets (no visible reloading of tiles as with "Map Proxy"). In addition, “PMTiles”, for example, can also be used to use hover effects in the viewer.

In contrast to the “2D Features” layer type, the “PMTiles” layer type can process significantly larger amounts of data.

So use the "PMTiles" layer type if you want to display a large number of features as a vector data set in the viewer.