Google already maps the world, but the Internet giant has bigger plans for its next location-based technology. The Alphabet unit wants to digitally map the interiors of buildings in 3D down to a resolution of a few inches and make money in virtual reality along the way through a project named Tango. The company plans a big expansion of the technology this year and ultimately wants to make it ubiquitous, according to a person familiar with the situation. Job postings and recent updates to Tango’s developer software show steps toward this ambitious goal. Google will showcase progress at its I/O developer conference near its Silicon Valley headquarters from May 18 to 20. Tango packs cameras and depth sensors along with other software into Android smartphones and tablets. Fire up the application and point the device at a space, and it sucks in images and depth information to recreate the environment on the screen and locates itself within that new digital realm. Google hopes Tango will support a system for independent developers to create new virtual reality applications and services. Video games could have characters that hide behind real-life furniture. A museum app could show 3D animations when you walk past an exhibit. A grocery store could highlight sale items and guide shoppers to the right shelf. Unlike most emerging virtual reality systems, Tango doesn't need external equipment to recreate the world digitally. And, unlike Google Maps, it can figure out the details of space without additional data sources. "Tango is the indoor extension of their outdoor mapping platform," said Lex Dreitser, a virtual reality developer who builds Tango applications. Tango started in a Google research lab more than two years ago, but the company is trying to take it mainstream this year. It's going into new smartphones from Intel and Lenovo Group, and the software has been updated to let it easily run on more devices. And there are signs Google is working on the most important challenge: making Tango 3D maps shareable so the company can someday patch them together into a single, detailed digital representation of many of the world's buildings, rooms and the stuff inside them.