The rise of gestural interaction led artists to produce shows, or installations based on this paradigm. We present the first stages of the " Sculpture numérique " (Virtual Sculpture) project. This project was born from a collaboration with dancers. Its goal is to propose bi-manual interactions in a large augmented space: we aim at giving dancers the possibility to generate and manipulate virtual elements on stage using their hands. The first set of interactions we present in this paper is 3D painting, where the user can generate 3D virtual matter from his hands. The movement of the hand defines a stroke, which shape is controlled by the shape of the hand. Changing the shape and orientation of the hand allows switching between three interaction modes to produce volumes, surfaces or curves in space. We explore the applicative case of dance, with the goal of producing a plastic creation from choreography.