Auto-fill fixtures to hit a target
Let OpenLumen place and space fixtures across a calculation area to reach your target light level, then tweak the result.
5 steps · 3 min read
Auto-fill is a starting point, not the final word: it gets you a uniform, on-target grid in seconds so you can spend your time refining edges, avoiding obstructions, and trimming fixture count. Because the target and all spacing follow your active unit system, the result reads correctly whether you design in footcandles or lux.
Select an area first
Auto-fill works on a calculation area, so draw or select one before you start. The area's Target light level (footcandles in Imperial, lux in Metric) is what the solver aims for, so set that on the area first.
Open Auto-Place Fixtures
Click the Auto fill area tool (the magic-wand icon) in the toolbar, or use Luminaires ▸ Auto Fill. The Auto-Place Fixtures panel slides in from the right, and ghost fixtures preview live on the canvas as you adjust settings.
Choose the luminaire and mounting
Pick which of your layout's luminaire types to place, then set the mounting height, rotation, and tilt. Height is entered in your active units (feet or meters). The fixture footprint (its physical width and length) is read from the IES file and used to stop fixtures from overlapping.
Pick an arrangement
Choose Auto (best fit) to let the solver decide, or force an In-line grid or Staggered pattern. For wallpacks or strip runs, enable Continuous run (end-to-end) and choose the run axis to place fixtures flush in a line, with an optional max run length.
Fit to target and place
With Fit to Target on, OpenLumen iterates: it lays out fixtures, calculates the resulting average light level, and adjusts spacing until it lands near your area target while keeping uniformity reasonable. Turn it off to use simple heuristic spacing instead. When the preview looks right, confirm to commit the fixtures — then fine-tune individual fixtures by hand if needed.