Alfred Hitchcock famously quipped that actors were no better than cattle, but in the future they may be a different breed entirely - pixels.
Talk about using virtual actors has been rife for the past decade, especially as it would mean that Hollywood could make movies without those multimillion-dollar movie star pay cheques.
Avatar gave the idea a boost, but James Cameron's creations were humanoid rather than human. Trying to make a believable virtual human on screen is still way beyond the grasp of today's technology, as examples on the internet show.
Scientific research into virtual acting has shown that our perception of humanity lies in the face, and especially in the eyes. Evolution has led us to be sensitive to the slightest change of facial expression and the most minimal eye movement.
Attempts to replicate these look scary, as the 'Heavy Rain Virtual Actor Demo' (YouTube) shows. This clip features a virtual actor - a 3-D animation - auditioning for a part. The body language is quite good, but the lack of movement in the face and eyes is disturbing. This is a problem that Germany-based Research and Development at the Institute of Animation is trying to solve.
The institute's 'Frapper' software aims to provide animators with the models for basic human face movement. This saves the animators time as they don't have to start from scratch on each virtual actor - they can focus on fine-tuning facial expressions.