Raster Caster

A QGIS plugin that casts elevation values onto a raster using surface polygons and elevation points stored in a GeoPackage.

Usage

The plugin adds a Raster Caster provider to the Processing Toolbox with two algorithms.

1. Begin new

Creates an empty GeoPackage in the CRS of your choice (EPSG:28992 by default) and loads its two layers into the project:

• surface (Polygon): the areas to cast.
  • definition_type = 'constant': param_1 holds the elevation value.
  • definition_type = 'tin': the elevation is interpolated from the elevation points inside the surface.
• elevation point (PointZ): supporting points for TIN surfaces. The elevation attribute is used, not the geometry Z value.

2. Cast

Burns the surfaces into a new raster. Constant surfaces are rasterized with their param_1 value; TIN surfaces are interpolated from the elevation points they contain.

• Input GeoPackage: a GeoPackage created by Begin new.
• Input Raster: optional; its pixel size is used for the output.
• Pixel Size: output resolution, required when no input raster is given.
• Snapping distance: search buffer around a TIN surface for elevation points that lie just outside it.

Without an input raster, the output extent follows the extent of the surface layer.

Development

Run the tests in the provided container:

docker compose build
docker compose run --rm qgis pytest

Build an installable plugin zip:

python zip_plugin.py