dusk

dusk is an OCCT-based replacement for the legacy dawn detector visualization tool. It reads STEP files (.stp) and produces SVG vector graphics of cross-section and perspective/isometric views.

A companion tool duskcut mirrors the dawncut cutting-plane utility.

Quick start

mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make -j$(nproc)

dusk — render a STEP file to SVG

dusk -d detector.stp [options]

View parameters are read from .DAWN_1.history in the current directory (same format as dawn, so dawn_tweak can be used directly). CLI flags override the history file:

Flag	Description	History line
--theta <deg>	Elevation angle (0=top, 90=side)	3
--phi <deg>	Azimuth angle	2
--mag <float>	Magnification	8
--draw <int>	1=wireframe 2=+hidden 3=outline	9
-x/-y/-z <float>	View target	5/6/7
--light-theta	Light elevation	19
--light-phi	Light azimuth	18
-o <file>	Output SVG (default: <stem>.svg)	—

duskcut — clip STEP geometry by a half-space

duskcut nx ny nz d input.stp [output.stp]

Same interface as dawncut. The plane n·x = d (mm) cuts the geometry; the half n·x ≤ d is retained.

Example — cross-section at x=0 keeping negative-x half:

duskcut -1 0 0 0 detector.stp half.stp

Drop-in replacement for dawn/dawncut

The existing generate_eps scripts in eic/epic/scripts/view*/ can be adapted by replacing:

• dawncut → duskcut
• dawn -d file.prim → dusk -d file.stp
• .prim input → .stp input (from convert-to-step CI job)

The dawn_tweak script works unchanged.

OCCT dependency

Requires OpenCASCADE 7.x (tested with 7.9.1). In the EIC software environment (eic-shell) it is available at /opt/software/linux-x86_64_v2/opencascade-7.9.1-*/.

License

Apache 2.0