Daylighting Study

Use this workflow when the main question is daylight performance rather than massing variety.

TODO screenshot: show a daylighting study scene with obstruction context and evaluated geometry visible, with the active daylight mode highlighted.

Before you start

Prepare:

• one GeoJSON boundary or a clean site setup,
• OBJ files for surrounding context,
• and either a planned massing model or geometry you will draw or import for evaluation.

1. Build the scene

1. Import the site boundary with Import GeoJSON....
2. Import surrounding context with Import OBJ....
3. For each surroundings object, review these properties:
   • Daylight Obstruction: turn on for geometry that should block daylight.
   • Add Daylight Sensors: turn on for control surfaces you want Urban Massing to evaluate.
   • Material Reflectance: use a realistic reflectance percentage.
   • Translation X/Y/Z: align imported models if needed.

2. Add or prepare the massing to evaluate

You can evaluate daylight on generated massing or imported/planned geometry.

If you already have massing in the project:

• keep it visible in the tree,
• make sure the geometry sits inside the correct site,
• and verify its height and orientation.

If you import a design object for shading-angle review, make sure the relevant object participates as a Daylight Obstruction so the daylight solver treats it as blocking geometry.

3. Configure daylighting inputs

In Properties, set these exactly:

• Country: selects the daylighting ruleset.
• North offset: rotates solar north relative to the scene Y axis.
• Direct sunlight target: required exposure in minutes.
• Summary shading angle: target angle for summary shading angle checks.
• Building reflectance: reflectance used for daylighting on building surfaces.
• Precision: Low, Medium, or High.
• Ground sensors: add sensors on the ground plane when you need outdoor daylight sampling.

Recommended workflow:

1. Use Low precision to confirm the setup.
2. Fix wrong north, wrong obstruction flags, or wrong translations.
3. Re-run with Medium or High when you trust the scene.

4. Choose a daylighting theme

Open Themes and enable one mode at a time:

• Direct Sunlight for exposure duration review.
• Daylight Factor for daylight factor review.
• Summary Shading Angle for obstruction-angle review.

These modes are best used one by one, because each answers a different question.

5. Navigate the model deliberately

Use the viewport to inspect:

• facades that are likely shaded by context,
• narrow courtyards,
• north-facing and south-facing edges,
• and areas near tall obstructions.

Useful controls:

• right-drag: orbit,
• Shift + right-drag: pan,
• right-drag with command/control: target zoom,
• mouse wheel: zoom,
• F: fit view,
• T: top view.

6. Read the daylight outputs

In Reports → Site, use these daylight values:

• Facade area under Direct Sunlight Sufficiency: share of facade meeting the direct sunlight goal.
• Facade area under Daylight Factor Sufficiency: average daylight factor performance across facade evaluation.

If you are comparing options, keep country, north offset, direct sunlight target, and precision identical between runs.

7. Iterate

If daylight is poor, change one thing at a time:

• move or edit the evaluated massing,
• change surroundings obstruction flags,
• reduce excessive depth,
• increase spacing from surroundings,
• or change overall orientation.

Then rerun the daylight evaluation and compare reports again.