Visual and haptic rendering pipelines exist concurrently and compete
for computing resources while the refresh rate of haptic rendering
is two orders of magnitude higher than that of visual rendering
(1000 Hz vs. 30-50Hz). However, in many cases, 3D visual
rendering can be replaced by merely displaying 2D images, thus releasing
the resources to image-driven haptic rendering algorithms.
These algorithms provide for haptic texture rendering in vicinity of
a touch point, but usually require additional information augmented
with the image to provide for haptic perception of geometry of the
shapes displayed in images. We propose a framework for making
tangible images which allows haptic perception of three features:
scene geometry, texture and physical properties. Haptic geometry
rendering technique uses depth information, that could be acquired
by a multitude of ways for providing haptic interaction with images
and videos in real-time. The presented method neither performs 3D
reconstruction nor requires for using polygonal models. It is based
on direct force calculation and allows for smooth haptic interaction
even at object boundaries. We also propose dynamic mapping
of haptic workspace in real-time to enable sensation of fine surface
details. Alternately, one of the existing shading-based haptic
texture rendering methods can be combined with the proposed haptic
geometry rendering algorithm to provide believable interaction.
Haptic perception of physical properties is achieved by automatic
segmentation of an image into haptic regions and interactive assignment
of physical properties to them.