Hi everyone,

I am quite new to Houdini, and even though I feel like I am barely scratching the surface of what this amazing software can do, I am absolutely blown away by its procedural power. I am still relatively inexperienced, so please forgive me if this turns out to be a beginner mistake. I did try searching the forums beforehand, but couldn't find a solution that fits my specific case.

I am currently struggling with importing and georeferencing large-scale terrain datasets (Digital Elevation Models) in Houdini.

I have successfully written custom Python SOPs to ingest 2D GeoJSON (roads/splines) and 3D CityJSON (LOD2 buildings). All vector datasets are successfully reprojected and aligned to a strict custom local origin / anchor point (converting UTM Zone 32N coordinates to a native 0,0,0 Houdini space to prevent floating-point precision issues).

Where I am stuck: I need to import the matching terrain, which consists of a large amount of individual GeoTIFF tiles (DGM1, each 1000x1000 pixels). Merging them into a single massive GeoTIFF prior to Houdini is not an option due to RAM and file size limitations of the final dataset.

To solve this, I generated a .vrt mosaic file in QGIS. However, Houdini's native Heightfield File SOP completely fails to load it, throwing the error: Invalid source /obj/.../heightfield_file1/cop2net1 (Error: Failed to open COP network).

This error occurs even when I test it with a tiny subset of just 4 files (each 1000x1000 pixels), so it is definitely a structural/driver issue or an error on my part rather than a system memory overflow.

What is the industry standard / most performant way to stream or sample tiled terrain data (VRT or raw TIFF tiles) directly onto existing geometry points or curves in SOPs?

Are there stable VEX methods that natively support VRT datasets, and how do I map the geographic extents (bounding box) to my already established local UTM offset?

Is there a way to bypass Heightfields entirely and read the metadata/pixel values directly from the .vrt/GeoTIFF file using Python or other nodes?

Any pointers to specific documentation, VEX functions, or workflows for tiled terrain streaming would be highly appreciated.

Specs: Houdini 20.5 & 21.0 / Windows 11

Thanks in advance!