Room lighting preview

How to use the room lighting preview

See how daylight and ceiling fixtures may read in a room before you plan a lighting change. Set the room size, window direction, sun position, fixture settings, and camera exposure, then inspect the room in 3D.

1. Enter the room width, depth, and window width in feet.
2. Set the latitude, date, and direction the window faces.
3. Choose the time of day with the slider.
4. Turn ceiling lights on or off and set the fixture count, lumens, and color temperature.
5. Drag the 3D view to look around the room and adjust Exposure to change the preview brightness.

What to enter

Latitude

Enter a value from -66 to 66 degrees. Use a negative value for locations in the southern hemisphere. The default is 40°N.

Date

Choose the date used for the sun position. The default is the current date on your device.

Window faces

Choose North, North-east, East, South-east, South, South-west, West, or North-west. The default is South.

Width

Room width in feet. The control accepts 8 to 30 ft and defaults to 16 ft.

Depth

Room depth in feet. The control accepts 8 to 30 ft and defaults to 13 ft.

Window

Window width in feet. The control accepts 2 to 14 ft and defaults to 6 ft.

Lights on

Show or hide the ceiling fixtures. The default is on.

Fixtures

Number of ceiling fixtures, from 0 to 9. The default is 4.

Each

Light output for each fixture, from 100 to 3,000 lumens. The default is 800 lm.

Colour temperature

Set fixture color from 2,200 K to 6,500 K in 100 K steps. The default is 2,700 K.

Exposure

Adjust the camera-like brightness from 0.30 to 2.50. The default is 1.00; higher values make the scene appear brighter.

Time of day

Choose local solar time from 4:00 AM to 9:00 PM in 15-minute steps. The default is 3:00 PM.

Preview a south-facing living room

Start with the defaults: a 16 ft × 13 ft room, a 6 ft window, four fixtures at 800 lm each, 2,700 K lights, latitude 40°N, and a south-facing window. Choose June 21 and set Time of day to 3:00 PM. The 3D overlay shows the sun's elevation and compass direction. If the sun is above the horizon and directed through the window, the preview displays “Direct sun through window.” Turn Lights on off to compare daylight alone with the four ceiling fixtures, then drag the view to inspect the room.

How the preview works

The tool builds a 3D room from the Width, Depth, and Window settings. It calculates a sun position from latitude, date, and local solar time, then aims the daylight toward the selected window-facing direction. The preview changes the sky color, sun direction, shadows, and sun color as the sun moves. Ceiling fixtures are placed in a grid across the room. Each fixture uses the selected lumens value and color temperature, while Exposure changes the camera-like brightness of the rendered view.

Reading the results

The overlay shows the sun's elevation in degrees and its compass direction when the sun is above the horizon. When the sun is below the horizon, it shows “Sun below horizon.” A “Direct sun through window” notice appears when the sun is above the horizon and its direction passes through the window. Drag the 3D scene to orbit around the room; panning is disabled.

Limitations and common mistakes

• This is a visual preview, not a photometric simulation. It does not model light bounces, clouds, or neighboring buildings.
• The result does not provide measured lux, foot-candles, fixture spacing guidance, or electrical calculations.
• The displayed time is local solar time, so it may not match clock time for a specific time zone or daylight-saving setting.
• Room dimensions and fixture settings are limited to the ranges shown in the controls.

Frequently asked questions