I asked Perplexity with “What is the scifi book from the 90s that had “ractors,” where a person would act in front of a camera and a computer would animate a CG model?”and got (what other commenters are saying) is the correct answer:

The science fiction book from the 90s that featured "ractors," where a person would act in front of a camera and a computer would animate a CG model, is not directly mentioned in the provided search results. However, based on the description of "ractors" and the context of computer animation and CG models, it seems you might be referring to "The Diamond Age" by Neal Stephenson, published in 1995. In this novel, the term "ractor" (short for "interactive actor") is used to describe performers who participate in interactive theater through virtual reality environments, which could align with the concept of acting in front of a camera to animate a CG model. However, since this specific detail is not found in the search results, this answer is based on existing knowledge outside of the provided sources.