Exa-MA WP1 - Terrain Mesh Generation for Urban Energy Modeling

Objective

During my internship, I focused on improving the terrain mesh generation process for urban energy simulations as part of the Exa-MA¹ project at Cemosis² a CNRS spin-off.

The goal was to build a C++ application to optimize 3D terrain mesh generation for finite element simulations in urban energy modeling. The pipeline sourced elevation data for any given geographical area using the Mapbox Terrain-RGB API³, processed it and used CGAL⁴ to create a Delaunay mesh constrained to contour lines.

Key Components

1. Terrain Mesh Generation

• Lambda-Generated Meshes:
  • Half-Sphere Terrain:
    • This mesh was generated using a lambda function representing a half-sphere:

• Wave-Like Terrain:
  • Another lambda-generated mesh with a wave-like surface:

• GPS Data-Driven Meshes:
  • Grenoble, France (Zoom Level 16):
    • A real-world terrain mesh generated using elevation data from the Mapbox Terrain-RGB API. This high-resolution mesh captures the detailed topography of Grenoble.

2. Contour Line Generation

• Implemented a method to generate and constrain terrain meshes along contour lines:

3. Re-Triangulation

• Using the CGAL library, the contour-constrained meshes were re-triangulated:

Impact and Future Work

The pipeline developed during this internship successfully reduced mesh complexity making large-scale urban energy simulations more computationally efficient.

Future work could involve merging multiple tiles for broader terrain coverage, optimizing performance for larger datasets, integrating urban elements such as buildings and vegetation to create more comprehensive models.

Read the project report here.

References