These notes describe how to recover the lighting layout of a DIALux
evo .evo project (luminaire positions, aiming directions, photometry and room
shells) from the project file itself, and how to rebuild that layout as a
Radiance scene. The work is interoperability-oriented file format analysis: only saved project files were
inspected, and the program itself was not examined.
The notes state what could be read, what could not, and how this relates to other
public work.
Independent work, not affiliated with, endorsed by or supported by DIAL GmbH. DIALux is a trademark of DIAL GmbH. The name identifies the application that saved the source files.
- Input: a DIALux evo
.evoproject file (observed with evo 5.13) - Output: luminaire world positions and emission directions, photometry as IES LM-63 files (limits in METHOD.md, section 8), and room shells (floor, walls, ceiling), mapped to Radiance
- Not covered: calculation results (
.rsl), the binary scene graph, furniture, textures, daylight. The converter also reads furniture. These notes are deliberately limited to the lighting layout and the room shell
| Topic | Status |
|---|---|
| Container (ZIP) and project record (ISO 10303-21 text) | Described. Also described by earlier public work (see RELATED_WORK.md) |
| Record grammar: field splitting, references, text escapes | Described. Decoded escapes: '', \X2\, \X4\ |
| Luminaire world position and emission direction | Described, including a known pitfall with arrays. The arrangement structure is also documented by evo-builder |
| Luminaire photometry (candela table + lumens -> IES -> Radiance) | Described as a data path, with limits (METHOD.md, section 8): the cd/klm scaling is an interpretation, the opening size is a placeholder, rotation about the light axis and the closing C plane are not written. The candela record layout is also documented by evo-builder. Not compared with DIALux results |
| Room shell (outline + height -> floor, walls, ceiling) | Described for two record variants |
Result files (.rsl) |
Structure observations only, not decoded, no illuminance values extracted |
Binary scene graph (ScenegraphScene) |
Not decoded |
| Light colour / colour temperature | Not validated. Neutral white is used |
- METHOD.md: the method, with the formulas
- RELATED_WORK.md: other public work on the
.evoformat and how these notes differ - PROVENANCE.md: method scope and evidence limits
- LICENSE: MIT OR Apache-2.0
- CITATION.md: how to cite these notes
Method notes. The working Python converter is in
ctlux-core (MIT OR Apache-2.0).
From the core repository root, its EVO command is
python3 -B -m core input.evo output. No sample project files, photometric
data or DIALux application files are included here.
The analysis and the findings are the author's. AI tools helped with wording and
with keeping the text organised.
The main derivation used one real project. Selected photometry checks
and .rsl header observations were repeated on a second project. The
underlying project files are not distributed (see METHOD.md, section 8).
Copyright (C) 2026 James Augustus
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