cea-external-tools 0.1.0

External tools for City Energy Analyst, mainly containing C++ components e.g. DAYSIM and CRAX

CEA External Tools Build Configuration

This directory contains the CMake configuration for building external tools required by the City Energy Analyst (CEA).

Structure

The build system has been modularized into separate configuration files:

• CMakeLists.txt - Main build configuration file
• DaysimConfig.cmake - DAYSIM-specific configuration and build logic
• CraxConfig.cmake - CRAX-specific configuration and build logic

Components

DAYSIM

Daylighting simulation tool that provides various radiation calculation utilities.

Executables built:

• ds_illum - Illuminance calculation
• epw2wea - Weather file conversion
• gen_dc - Daylight coefficient generation
• oconv - Octree conversion
• radfiles2daysim - Radiance file conversion
• rtrace_dc - Ray tracing for daylight coefficients

CRAX

City Radiation Accelerator for fast urban radiation simulations.

Executables built:

• radiation - Main radiation calculation engine
• mesh-generation - 3D mesh generation utility

Build Options

You can control which components to build using CMake options:

# Build both components (default)
cmake -DBUILD_DAYSIM=ON -DBUILD_CRAX=ON ..

# Build only DAYSIM
cmake -DBUILD_DAYSIM=ON -DBUILD_CRAX=OFF ..

# Build only CRAX  
cmake -DBUILD_DAYSIM=OFF -DBUILD_CRAX=ON ..

CRAX-specific Options

CRAX has additional configuration options for Python wheel builds:

• CRAX_USE_DYNAMIC_ARROW (default: ON) - Enable dynamic Arrow linking to save space in wheels
• CRAX_USE_AUTOMATED_DEPENDENCIES (default: ON) - Use automated dependency fetching

Source Configuration

Both tools support local source directories or automatic fetching from GitHub:

DAYSIM

• DAYSIM_SOURCE_DIR - Path to local DAYSIM source (default: ./daysim)
• DAYSIM_GIT_REPOSITORY - Git repository URL (default: https://github.com/reyery/Daysim.git)
• DAYSIM_GIT_TAG - Git tag/branch to use

CRAX

• CRAX_SOURCE_DIR - Path to local CRAX source (default: ./crax)
• CRAX_GIT_REPOSITORY - Git repository URL (default: https://github.com/wanglittlerain/CityRadiation-Accelerator-CRAX-V1.0.git)
• CRAX_GIT_TAG - Git tag/branch to use

Installation

The built executables are installed to the CEA resources directory:

• DAYSIM tools: cea/resources/radiation/bin
• CRAX tools: cea/resources/radiation/bin

Build Targets

The build system includes a custom target cea_all that builds all required CEA components:

# Configure build
cmake -B build -S .

# Build all CEA targets (recommended)
cmake --build build --target cea_all

# Or build all targets
cmake --build build

# Install to CEA resources
cmake --install build

Compiler Warnings

The build system automatically suppresses common warnings for cleaner output:

• GNU/Clang: Suppresses missing prototypes, unused variables, sign comparison, and deprecated declarations
• MSVC: Suppresses warning C4127 to prevent build failures on Windows