# Edit Drawing
Note
VJMap supports editing CAD drawings: adding, modifying, deleting, and copying entities. However, VJMap focuses on CAD GIS display and visualization; editing capabilities are relatively limited.
# Principle
For a complete example with delete, modify, add, and export to CAD, see: https://vjmap.com/app/visual/#/draw?mapid=p5ff2aa38c0f&version=v1&mapopenway=GeomRender&vector=true&theme=dark (opens new window)
https://vjmap.com/demo/#/demo/map/comprehensive/05drawcadedit (opens new window)
CAD editing works as follows:
Modify the original CAD drawing. You can add, modify, or delete entities. After saving, the backend creates a new version. Example: https://vjmap.com/demo/#/demo/map/service/05zfrommap (opens new window)
Use style modifications to change how the CAD drawing is displayed without changing the underlying data. This only affects frontend display and is more performant. Example: https://vjmap.com/demo/#/demo/map/service/05zgmodifymap (opens new window)
The main idea behind modifying display via style:
(1) The backend controls rendering through styles. You can use the expression syntax to show/hide specified layers or entities and change colors. This creates a new style name on the server. When opening the map, specify this style name so the generated tiles reflect your custom display.
(2) The frontend can add a draw layer to draw points, lines, polygons, and other shapes. Combine backend style control with frontend drawing to achieve the desired result.
# Video Tutorial
Online Demo (opens new window)
Note
Due to data security, the trial version cannot download the generated DWG file. You can only view the generated drawing online. The full version allows download in the backend settings.