# Web Map Application
As a map engine, VJMap vjmap can not only load CAD map tiles, but also directly load web map tiles, and supports overlay display of CAD maps and web maps.
# Load Web Map Directly
Load web maps by providing WMTS tile URLs.
Note
VJMap does not provide web map tile data. For offline deployment of web map services, please download web map offline tile data yourself or use third-party tools.
# Web Map and CAD Map Overlay (Web Map as Base)
This scenario uses the web map as the base (web map as coordinate system), calling VJMap CAD map's WMS service to adapt to the web map for overlay display.
If the CAD map has a geographic coordinate system (e.g. CGCS2000), it can be overlaid automatically.
If the CAD map has no coordinate system, you must specify three or more common points for calibration to compute the four parameters (xy translation, rotation, scale) for overlay.
See the Coordinate Transformation document for details.
This scenario suits cases where most business data is web map data and the CAD map is only overlaid for reference.
# CAD Map and Web Map Overlay (CAD Map as Base)
This scenario uses the CAD map as the base (CAD map as coordinate system), calling VJMap's web map WMS service to adapt to the CAD map for overlay display.
If the CAD map has a geographic coordinate system (e.g. CGCS2000), it can be overlaid automatically.
If the CAD map has no coordinate system, you must specify three or more common points for calibration to compute the four parameters (xy translation, rotation, scale) for overlay.
See the Coordinate Transformation document for details.
This scenario suits cases where most business data is CAD data and the web map is only overlaid for reference.
Note
For more on web map overlay display, see the Web Map document.