Interactive 3D map of OB star density iso-surface (1.0, 1.38 and 2.76 × 10^-4 OB star per pc³; visible on a 3D-PDF compatible reader, like Adobe Acrobat Reader). The known stellar groups from Kharchenko et al. (2013) and candidate stellar groups from Platais et al. (1998) are represented by grey points and their names are indicated. The Orion supergiants are represented by green points. The Gould belt ellipse fit of Perrot & Grenier (2003) is represented in magenta. Nearby HII bubbles are represented as red spheres. Features can be toggled using the following buttons: (See PDF).