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name: raster-dem-and-basemaps description: "Use BlenderGIS raster, DEM, ASCII grid, web elevation, basemap, cache, and image-engine workflows." disable-model-invocation: true metadata: disco-role: operating license: GPL 3.0

Raster, DEM, and Basemaps

Use this sub-skill when a task involves BlenderGIS georeferenced raster import, ASCII grid import, raster-as-DEM terrain creation, web DEM download, or the interactive basemap tile viewer.

Load This First

1. For concrete operator sequences, read references/workflows.md.
2. For operator IDs, class/function surfaces, option names, and engine behavior, read references/api-reference.md.
3. For raster, world-file, ASCII grid, web DEM, tile-service, and GeoPackage cache formats, read references/data-formats.md.
4. For failures and recovery, read references/troubleshooting.md.
5. To preflight an image/world-file pair outside Blender, run scripts/inspect_georaster.py. It uses Pillow when available and does not require GDAL.

Covered Workflows

• importgis.georaster import modes PLANE, BKG, MESH, DEM, and DEM_RAW.
• importgis.asc_file ASCII grid modes MESH and CLOUD.
• importgis.dem_query web DEM download and follow-on DEM import.
• view3d.map_start, view3d.map_viewer, and view3d.map_search basemap viewing, search, export-to-mesh, and tile caching.
• Optional raster/image/projection engines: GDAL, Pillow/PIL, ImageIO FreeImage, pyproj, and built-in fallbacks where BlenderGIS supports them.

Route Elsewhere

• Generic scene CRS/origin repair, custom CRS presets, GeoScene, SRS, and reprojection engine selection: ../georeferencing-and-crs/.
• OSM vector query/import and Overpass tag filters: ../vector-data-and-osm/.
• Terrain triangulation, terrain-analysis material nodes, drop-to-ground, and earth-sphere/curvature transforms after data import: ../terrain-mesh-and-analysis/.
• Georeferenced camera render output and world-file render export: ../geocameras-and-rendering/.
• Cross-cutting add-on enablement, logs, optional dependency checks, and privacy guidance: ../../references/addon-overview.md and ../../references/troubleshooting.md.

Quick Decision Guide

• Need a flat georeferenced image in the scene: use importgis.georaster with importMode='PLANE'.
• Need a non-rendering viewport reference image and the raster is not rotated/reprojected: use importMode='BKG'.
• Need to drape an image onto an existing georeferenced mesh: use importMode='MESH'.
• Need elevation as a displacement modifier: use importMode='DEM' and decide fillNodata, subdivision, step, and demOnMesh deliberately.
• Need actual DEM vertices/point cloud: use importMode='DEM_RAW' or ASCII importMode='CLOUD', usually with step > 1 for large rasters.
• Need online context imagery: use view3d.map_start; verify image engines and cache folder before blaming the map service.
• Need OpenTopography SRTM/GMRT elevation: use importgis.dem_query; confirm scene georef, extent size, latitude range, network, and OpenTopography API key requirements first.