Have you ever wondered why statues made from wax or quartz look different to ones made from stone? It could have something to do with the perception of shape and opacity.
Scientists based in the School of Optometry and Vision Science at UNSW recently conducted a research study looking at how our brain perceives the 3D shape of opaque and translucent objects. They found that the perception of bumps on the surface of the same 3D object look less deep and less steep than identical bumps on an opaque object.
The work was innovative, because the researchers were not limited to using graphical simulations; they chiselled out crevices in an actual candle, and then photographed it. They then painted it using an opaque acrylic paint and rephotographed for comparison. Not only did it look more opaque, the surface also looked bumpier.