Usually, holograms placed in real environments through Microsoft HoloLens do not have a shadow. This is mainly due to technical reasons of the HoloLens display, as I’ll discuss in a later blog post.
However, for the scene perception and to correctly determine the holographic object position in the real-world 3D space, as well as for the “feeling” that the scene looks real, shadow is of tremendous importance.
Study on Shadow in Augmented Reality
To get exact numbers and to better understand the situation, I’ve written my Bachelor Thesis “Benefits and Parameters of Shadow in Augmented Reality-Environments” in 2004. Even though back then the study was done with marker-based Augmented Reality, the general setting is comparable to scenes created with HoloLens.
Using an experimental approach, 23 participants were tasked with conducting tests and filling out a questionnaire, judging different AR situations. The tool to create the AR scenes was ShadowAReality by Stephan Drab et. al.
Why Shadow is Important for AR
Literature research showed that shadows are of significant importance for realistic perception. They allow a correct estimation of the placement of objects in the virtual direction, as well as the distance to the camera. Furthermore, shadow defines the volume of the object. Overall, shadows contain a big amount of additional information, which obviously lacks if shadows are missing. They play an important role in how realistic a scene looks. Continue reading “Benefits and Parameters of Shadow in Augmented Reality-Environments, Part 1”