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Sunlight

Cumulative direct-sun hours on surfaces, with a live heatmap.

AvailableGuide · 2 min read

Sunlight Hours computes how many hours of direct sun reach a surface over a chosen period, and paints the result as a live heatmap on your geometry.

How it works#

From each tested point, the study casts a ray toward the sun's position at intervals across the period and counts the ones that arrive unobstructed. Context geometry in your group or selection does the blocking. The reference is checked against closed-form solar physics, and every faster way of running the study is checked against it, so the answer doesn't depend on your hardware.

One ray per time step, from the sun to the sensor. The ones that arrive unobstructed add up to the sunlight hours.

Every sensor runs the same count, so the result is a field: one value per point, read as a heatmap. The drawing below runs it over a sample site for one day, 21 June at 52° N. The hatching is where the blocks' shadows fall at the hour shown, and the colour is each point's hours of sun so far.

A sample site through one day. The open ground to the north-west has sun all day; the narrow gap between the slab and the tower, and the strip just north of the slab, get the fewest hours. Move the pointer over the sky to move the sun.

Running an analysis#

  1. Set up geometry. Organize target surfaces and surrounding context into a group, or select them in Rhino.
  2. Open the Sun tab in the Wrengler panel.
  3. Set parameters: location (sync from Rhino or set manually), date range (a single day or a season), and time resolution (the interval between sun positions, e.g. 15 minutes).
  4. Run. The heatmap appears on your geometry in the viewport.

Live Mode#

With Live Mode enabled, the engine stays active in the background: change building heights or setbacks and the heatmap follows.

Tip

Use Live Mode during early massing to read the solar consequence of a move as you make it, rather than waiting on a bake.

Study size#

On Free, one study covers up to 2,500 m² of analysed surface, about 50 × 50 m: a house and its garden, an extension and the neighbouring gardens, a small courtyard. The area is measured from the surfaces you analyse, so the grid spacing does not change it. There is no monthly limit, and any period and resolution runs.

A larger study needs Wrengler Pro. Before one runs, Wrengler checks your subscription online, so it needs a connection. A check is reused for about ten minutes while you work.

Performance tips#

  • Grid resolution: finer grids give smoother heatmaps but cost more compute. Start medium for live feedback.
  • Context complexity: on large urban models, keep the group focused on geometry that actually shades your target.