Improbable, a developer of virtual reality creation software, has closed a series B round led by SoftBank that will be used to enhance its SpatialOS platform.

Telecommunications and internet group SoftBank led a $502m series B round for UK-based virtual reality development software provider Improbable today that valued the company at more than $1bn.

Venture capital firms Andreessen Horowitz and Horizons Ventures also participated in the round, both having previously contributed to the company’s series A round along with Singaporean state-owned investment firm Temasek.

Improbable will use the funding to further develop its technology, and in particular SpatialOS, the distributed operating system it has built in…