One of the defining aspects of Cédric Plessiet and Georges Gagneré’s avatar creations is an expressive responsiveness. These two artists and researchers make use of the techniques and processes of on-set previsualization, which allows directors and performers to control avatars in real time, in a virtual environment that is nearing its final stage. In this paper, Cédric Plessiet uses his series of interactive portraits "Les Double-Autres [The Double Others]" to illustrate Taupipeline, a software architecture that allows him to establish a dialogue with the physical models on which his realistic avatars are based. In turn, Georges Gagneré writes about his work directing shadow avatars in his performance "L’Ombre [The Shadow]", based on H. C. Andersen’s homonymous tale. To conclude, the two artists talk about how their processes complete each other in their next joint research-creation project, "Les Spectateurs [The Spectators]".