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Bypassing the Uncanny Valley with Hands

The Uncanny Valley was introduced by Japanese roboticist Masahiro Mori in 1970, as a term referring to the hypothetical valley in which human-like fascimiles suddenly go from 'cute' to 'vile' with almost no warning.

For decades it has been the bane of creating realistic CG bodies and bodyparts. If you made something too real, it would not be perfect, and thus would enter into the 'so real it is creepy' dip of the valley. Typically, a less realistic body would garner a better response, explaining why so many cartoony VR forms exist - we cannot get to 'real' so cartoony has the added cute factor, to help uptake. However, the ultimate goal of creating virtual bodies that look and feel totally natural has never waviered, and would be a significant force for uptake.

In August 2008, the first hand and forearm pairing was achieved which realistically achieves this, bypassing the uncanny valley for the lower arm.

University of British Columbia animators used anatomical data from medical images to create a physics model of the 17 bones and 54 tendons and muscles of the hand and forearm. It literally is a physical hand turned virtual. The bone structure being laid down first, determining pivot points. The tendons follow that, joining onto the bones and acting as hinges. Each deforms by only a set amount, immediately constraining how the wrist and hand can move, to realistic degrees. Major muscles were added on top of the tendons, adding further strength calculations, and finally the entire thing was skinned with metaballs so the skin would deform completely naturally.

The hand model is barely able to move in real-time currently, but of course we all know that as processing power marches steadilly onwards, that is unlikely to remain a problem.


Initially it will be used to shed light on the mystery of how the tendons and muscles of the human hand interact when we move. The aim of the project is to help surgeons reconstruct damaged hands more effectively. Of course, betyond that, a completely naturallty moving and animating arm, is a part of the completely naturally animating whole body we need, to move beyond the uncanny valley in all avatar based VR, for once and for all.


Virtual hand gets under the skin

Shinjiro Sueda, University of British Columbia

Hand animation project page and paper

Further Reading

Resource List: Fighting the Uncanny Valley

Staff Comments


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