Sign language is the primary means of communication for the Deaf and Hard of Hearing (DHH) community. As the production of digital media grows, relying solely on human interpreters is not always feasible, creating the need for automated, scalable solutions. Signing avatars offer a promising approach, but present significant challenges due to the linguistic and expressive complexity of sign languages. This thesis presents a prototype system that dynamically generates Italian Sign Language (LIS) sentences on a MetaHuman 3D avatar by smoothly blending individual signs recorded through motion capture. The system was developed at the Rai Centre for Research, Technological Innovation and Experimentation (CRITS), extending their existing platform for generating fixed sentences.