In this work we present a complete methodology for robust authoring of AR virtual characters powered from a versatile character animation framework (SmartBody), using only mobile devices. We can author, fully augment with life-size, animated, geometrically accurately registered virtual characters into any open space in less than one minute with only modern smartphones or tablets and then automatically revive this augmentation for subsequent activations from the same spot, in under a few seconds. Also, we handle efficiently scene authoring rotations of the AR objects using Geometric Algebra rotors in order to extract higher quality visual results. Moreover, we have implemented a mobile version of the global illumination for real-time Precomputed Radiance Transfer algorithm for diffuse shadowed characters in real-time, using High Dynamic Range (HDR) environment maps integrated in our open-source OpenGL Geometric Application (glGA) framework. Effective character interaction plays fundamental role in attaining high level of believability and makes the AR application more attractive and immersive based on the SmartBody framework.