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PDF Terrain — Survey to 3D Terrain Generator

Part of: FederatedModel Spatial Database · Bonsai addon for Blender

Paper survey plans become 3D terrain meshes via OCR. 689 elevation points extracted from real civil survey — the bridge between land survey and spatial MRP.

Status: POC complete. 689 elevation points extracted from real civil survey.

What It Does

Converts survey drawings (PDF/PNG) into 3D terrain for BIM workflows:

PDF survey → Google Vision OCR → elevation points → 3D point cloud → IFC + DXF

A civil engineer's survey plan — the paper document with handwritten elevation numbers — becomes a 3D terrain mesh that the BIM Compiler can place buildings on. This is the bridge between land survey and spatial MRP.

PDF Terrain — 689 elevation points extracted from civil survey, rendered as 3D terrain in Blender
689 elevation points extracted from real civil survey. 294m × 229m site. Rendered in Blender/Bonsai.

Why It Matters for the ERP Paradigm

In iDempiere, a C_Project groups C_Orders on a site. But a site is not flat — it has topology (slopes, ridges, drainage paths). The terrain mesh provides the physical surface that M_Locator plots sit on. Without terrain, plot placement is 2D grid arithmetic. With terrain, it becomes real-world site engineering:

  • Cut-and-fill volumetrics — how much earth to move
  • Grading strategy — which plots need fill, which need cut
  • Infrastructure routing — drainage follows terrain slope
  • 4D scheduling — earthworks before foundations

Key Features

  • Automatic elevation point extraction via Google Vision API
  • API caching — one-time call per survey, no repeat charges
  • IFC export (IfcGeographicElement per point, under IfcSite)
  • DXF export for AutoCAD/Civil 3D compatibility
  • Orthographic camera view for technical review
  • Reference image overlay in Blender viewport

Proof of Concept

Metric Value
Points extracted 689 from real civil survey
Survey area 294m × 229m
Elevation band 20m (40m–60m)
Coordinate accuracy Affine-transformed from pixel to world
Exports IFC + DXF verified in Revit and AutoCAD

How It Connects

Dimension Role
3D Terrain mesh — the physical site surface
4D Earthworks sequencing (cut before fill, grade before foundations)
5D Cut-and-fill volumes × earth-moving rates = site preparation cost
Infrastructure Road/rail alignment follows terrain topology

Source

Repository: red1oon/IfcOpenShell (branch: feature/IFC4_DB)

See INFRA_DESIGNER_SRS.md for the infrastructure designer that consumes terrain data (4 snap modes: ON_SURFACE, ABOVE, BELOW, PIER).