Abstract: In one aspect, a method for augmenting a physical environment with projected media content from a virtual environment, using a handheld spatially aware mixed reality projection platform, includes the step of providing a handheld spatially aware mixed-reality projection device. The method includes the step of with a mapping application in the handheld spatially aware mixed-reality projection device. The method includes the step of relocalizing the handheld spatially aware mixed-reality projection device based on a virtual three-dimensional map of a physical environment. The relocalizing generates pose information of the handheld spatially aware mixed-reality projection device in the physical environment with respect to the virtual three-dimensional map. The method includes the step of sharing the set of three-dimensional pose information with a game engine application of the handheld spatially aware mixed-reality projection device.