Perceived rigidity is not enough to explain why shape from specular flow in 3D-rotating objects is difficult

Nahide Dicle Dövencioglu, Maarten Wijntjes, Ohad Ben-Shahar, Katja Doerschner

Research output: Contribution to journalArticlepeer-review


Surface reflectance and motion characteristics affect the perceived shape of 3D dynamic objects.
Results from our group (Doerschner, 2013; Dovencioglu, 2015) suggest that the perceived local
and global shape of specular objects substantially differ from that of matte objects. This is possibly
due to the fact that shape from specular flow is somewhat more difficult to solve for the visual
system. For example, observers frequently report perceiving non-rigidity when judging the shape
of moving specular objects. Here we explored this idea formally. We used low, mid and high
amplitude, matte and specular bumpy objects that rotated around either the vertical or viewing
axis. Observers compared these test objects to a mixed material (half-specular, half-diffuse) object
of the same bumpiness and they picked which object looked more rigid. Here, we found that
specular objects were perceived as less rigid for all levels of bumpiness magnitudes, there was no
effect of rotation axis on the rigidness judgements. In previous bumpiness judgements, specular
objects appeared flatter when rotating in-plane. Current results combined with our previous
58 Perception 45(S2) reports suggest that it is difficult to retrieve shape from specular flow but this cannot be solely explained by perceived rigidness from specular flow.
Original languageEnglish GB
Pages (from-to)58-59
StatePublished - 2016


Dive into the research topics of 'Perceived rigidity is not enough to explain why shape from specular flow in 3D-rotating objects is difficult'. Together they form a unique fingerprint.

Cite this