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Grasshopper Plugin (Rhino 3D)

USC provides 15 custom Grasshopper components for visual parametric workflows in Rhino.

Installation

Copy all .ghuser files from grasshopper/USC_GHplugin/ to your Grasshopper User Objects folder, or drag them onto the Grasshopper canvas.

Daemon

The plugin communicates with a persistent daemon process that keeps the CUDA context warm for sub-second response times:

urbansolarcarver daemon start       # start GPU daemon
# ... use Grasshopper components ...
urbansolarcarver daemon stop        # stop when done

The daemon binds to localhost only and uses a random authkey for authentication.

Components

All components are prefixed with USC_:

Session management

  • USC_Session -- daemon lifecycle and CUDA initialization. Wire a Boolean True to the start_daemon input to launch the daemon; leaving it unconnected keeps the component idle.

Configuration (Tier 1)

  • USC_Config -- build a pipeline configuration from visual parameters
  • USC_AnalysisPeriod -- define the analysis date/time range
  • USC_GridSettings -- voxel size, ray length, surface sampling
  • USC_RaySettings -- ray batch size, altitude limits
  • USC_BenefitParams -- balance temperature and offset for benefit mode
  • USC_TiltedPlane -- fixed-angle envelope parameters
  • USC_RadCool -- radiative cooling parameters (dew point, Bliss constant)
  • USC_Threshold -- thresholding strategy, score smoothing, and column carve-above post-processing. Connect output to USC_ThresholdStage's threshold_overrides input (not Config) so threshold changes only re-run thresholding.
  • USC_PostProcess -- smoothing and cleanup settings. Connect output to USC_Export's postprocess_overrides input (not Config) so mesh cleanup changes only re-run export.
  • USC_Diagnostics -- enable/disable diagnostic exports

Pipeline execution (Tier 2)

  • USC_RunPipeline -- run all three stages in one go (quick prototyping)
  • USC_Preprocess -- run preprocessing only (ray tracing + scoring). Errors turn the component red.
  • USC_ThresholdStage -- run thresholding only. Accepts threshold_overrides directly. Errors turn the component red.
  • USC_Export -- run exporting only. Accepts postprocess_overrides directly. Errors turn the component red.

Input geometry

Test surfaces must be individual flat panels. If you are using extruded block boundaries or any joined polysurface, explode it into its constituent faces before connecting to USC_Preprocess -- otherwise the planarity check will reject the combined surface and preprocessing will fail with a "No points sampled" error.

Use the decomposed pipeline (Preprocess → ThresholdStage → Export as separate components) rather than RunPipeline. This lets you:

  • Adjust threshold parameters (USC_Threshold → USC_ThresholdStage) and re-export without re-running the expensive ray-tracing step.
  • Adjust mesh cleanup settings (USC_PostProcess → USC_Export) and regenerate the mesh without re-thresholding or re-preprocessing.

Only USC_Preprocess needs to re-run when you change geometry, mode, or the analysis period.