Visualization by 100CGI Studio for an interior architecture practice: The Obsidian Forum, a 1,200 sq m corporate headquarters in Riyadh's King Abdullah Financial District. Six stills were delivered in 18 days.

The scheme turns almost every overhead plane matte black, and that is the hardest surface in the room to keep. Polished dark stone fails by turning into a mirror. Matte black fails the other way: it absorbs nearly everything you throw at it.

Underexpose the acoustic rafts and they crush into a hole above the room, with no texture and no edges. Overexpose them and they drift to a washed-out grey that reads as cheap paint. The renders live inside that narrow band.

The dark timber panelling is modelled rib by rib rather than faked with a bump map, so light breaks across it the way it will on site. Shaders were calibrated surface by surface: black acoustic rafts with recessed LED lines, walnut millwork, terrazzo with dark aggregate, cognac leather.

Then four layers of light went in: daylight through full-height glazing, the linear LEDs inside the rafts, shelf lighting in the joinery, and brass lamps in the soft seating.

Rendered in 3ds Max and Corona. Full case study: The Obsidian Forum.