This document discusses haptic technology, which adds the sense of touch to interactions with computers. It describes how haptics works using devices like haptic interfaces and actuators. Key aspects of haptic rendering like collision detection and force response algorithms are explained. Applications of haptics in areas like gaming, virtual reality, robotics and education are presented. Future directions like wearable haptics and using ultrasound for touchless haptics are also covered. The document concludes by describing algorithms for haptic rendering of constructive solid geometry trees.

1. Presented by
Mrs. B.Arulmozhi, M.Sc., B.Ed., M.Phil., SET.,
NET.,
Assistant Professor and Head, Department of
Computer Science and Applications
D.K.M. College for Women, Vellore
HAPTIC TECHNOLOGIES AND
ITS APPLICATIONS

2. HAPTIC TECHNOLOGY

3. Introduction – Haptic Technology
 Haptics is the technology of adding the sensation of
touch and feeling to computers.
 “Haptic”, is the term derived from the Greek word,
“haptesthai”, which means ‘sense of touch’.
 It is defined as the “science of applying tactile
sensation to human interaction with computers”.
 It permits users to sense (“feel”) and manipulate three
dimensional virtual objects with respect to such
features as shape, weight, surface textures, and
temperature.

4. HISTORY
 Haptic- Introduced by 20th century researcher in the
field of experimental psychology to refer to the active
touch of real objects by humans.
 In the late 1980s, the term was redefined to enlarge its
scope to include all aspects of machine touch and
human–machine touch interaction.
 Currently, the term has brought together many
different disciplines, including biomechanics,
psychology, neurophysiology, engineering, and
computer science, as the study of human touch and
force feedback with the external environment.

5. Generation of Haptic
 First Generation – Use of Electromagnetic
Technologies which produce a limited range of
sensations.
 Second Generation – Touch-Coordinates
specific responses allowing the haptic effects to
be localized to the position on a screen rather
than the whole device.
 Third Generation – Delivers both Touch-
Coordinate specific responses and
customized haptic effects.
 Fourth Generation – Pressure Sensitivity, i.e.
how hard you press on a flat surface can affect
the response.

6. KEY COMPONENTS
Haptic Interface
Sensors
Control
Software(MCU)
Drivers
Actuators

7. HOWHAPTICWORKS

8. 1. Cyber grasp
2. Phantominterface
Haptics devices

9. Haptics Feedback
 Haptics is implemented through different type of
interactions with a haptic device communicating
with the computer. These interactions can be
categorized into the different types of touch
sensations a user can receive.
•Tactile feedback
•Refers to a sensations felt
by the skin .
•Allow the user to feel things
such as the texture of
surfaces, temperature and
vibration.
•Force feedback
•It reproduces the directional
forces that can result from
solild boundaries.
•E.g. the weight of virtual
object, inertia etc.

10.  It is the process of generating and
computing forces in response to the
user interaction with the virtual object.
 The software – controlled haptic
virtual objects(HVO) creation process
is called haptic rendering(HR).
 The control computer(CC) executes
HR events (Collision detection, force
calculation and generation when
necessary) at high rate(one KHz or
more).
Haptic rendering

11.  It has 3 main blocks
1. Collision detection
algorithms
2. Force-response
algorithms
3. Control algorithms.
Haptic rendering – continue

12. Haptic rendering – continue

13. HAPTIC RENDERING in CONSTRUCTING 3D OBJECT
 Constructive solid geometry
(CSG) has proven to be a
good metaphor for
constructing complex objects.
 These complex objects are
created by applying boolean
operations on simple,
mathematical objects.
 For instance, a box with a hole
can easily be defined as a
cylinder subtracted from a box.

14. Csg tree
 A CSG model consists of a
series of primitives and
boolean operators, which are
grouped into a tree.
 Most CSG implementations
use the intersection (∩),
subtraction (−) and union (∪)
operators.
 In this CSG tree, the
intersection of a cube and a
sphere is taken, which
results in a rounded cube.
Next a hole is created by
subtracting a cylinder from

15. HAPTIC RENDERING of CSG TREES
 These algorithms either use special hardware
with 2 depth buffers or the stencil buffer
available on standard OpenGL graphics board.
 Our algorithm for rendering CSG trees
calculates a surface contact point (SCP) for
CSG models. A primitive has to provide two
methods in order to be used in a CSG tree:
1. The primitive has to check if a point
lies inside or outside its surface.
2. The primitive has to calculate the SCP if
the point lies inside its surface.
3. The primitive has to calculate the SCP if
the point lies outside its surface.

16. INTERSECTION algorithm
 The intersection of two
objects is formed by the
volume that is shared by
these objects.
 As a result, only the
surfaces that are shaded
black in figure have to be
felt. The rendering
algorithm should ignore
the greyed surfaces.

17.  When subtracting an object
from another object, the
resulting object is defined by
the volume of the latter object
that is not shared with the
former.
 The inside-outside test of a
subtraction node should
succeed if the left subtree’s
inside-outside test succeeds
and the right subtree’s
insideoutside test fails.
 For our example, the resulting
object that is formed by
subtracting a cube from a
sphere is shaded black
Subtraction algorithm

18.  The union of two objects
is defined as the points
in space that are
enclosed by either of
the objects.
 The grey surfaces in
this figure define the
intersection of the two
objects.
Union algorithm

19.  A CSG tree can be converted to a normal form by
repeatedly applying the following set of production rules to
the tree. These production rules make use of the
associative and distributive properties of boolean
operations:
 1. X −(Y ∪Z)→(X −Y)−Z
 2. X ∩(Y ∪Z)→(X ∩Y)∪(X ∩Z)
 3. X −(Y ∩Z)→(X −Y)∪(X −Z)
 4. X ∩(Y ∩Z)→(X ∩Y)∩Z
 5. X −(Y −Z)→(X −Y)∪(X ∩Z)
 6. X ∩(Y −Z)→(X ∩Y)−Z
 7. (X −Y)∩Z →(X ∩Z)−Y
 8. (X ∪Y)−Z →(X −Z)∪(Y −Z)
 9. (X ∪Y)∩Z →(X ∩Z)∪(Y ∩Z)
Tree normalization

20.  The haptic load is defined as the percentage of the
processor time that is needed to perform the haptic
algorithms.
 This haptic load includes (but is not limited to) the time
needed to read the haptic device’s encoders, to
evaluate the haptic scene graph and to sent force
back to the device.
 The PHANToM device drivers, however, include a
utility that visually shows the haptic load. Since this is
the only way to assess the haptic load, this tool is
currently considered a valid means to measure the
performance of haptic algorithms.
analysis of algorithm

21.  Table 1 compares the
haptic load for empty
scene, object not touched
and object touched by
some pointing device.
 Since an empty scene
requires a haptic load of
±25% and the haptic load
must always be less than
90%, ±65% of the
processor time is still
available for the
calculation of the CSG
Results of algorithm

22. Applications of haptics technology
 Computer and video games
- Haptics feedback is
commonly used in arcade
games, especially racing
video games.
 Mobile Devices – Tactile
haptics feedback is becoming
common in cellular devices.

23.  Personal Computers-
Apple’s Macbook and
Macbook pro started
incorporating a “tactile
touch pad” design.
 Virtual Reality – Haptics
are gaining widespread
acceptance as a key part
of virtual reality systems.
Applications of haptics technology

24.  Medicine – Haptic
interfaces for medical
simulation may prove
especially useful for
training in minimally
invasive procedures such
as laparoscopy and
interventional radiology
as well as for performing
remote surgery.
Applications of haptics technology

25.  Robotics – Haptic
technology is also
widely used in
teleoperations or
telerobotics.
 Arts and Design –
Haptics is used in
virtual arts, such as
sound syntheisis or
graphic design and
animations.
Applications of haptics technology

26.  Hologram with haptic
Using this feedback, the user
receives tactile response from
holograph as if it were a real object.
It is based on using ultrasound
waves thereby creating acoustic
radiation pressure. It is through
tactile response that user percieves
the object.
 Haptic in Biometric
The haptic based biometeric
measure the position, velocity
and force. After these
measurements using
algorithms, unique physical
patterns can be developed
which can be used for
identification.
Future Applications

27.  Haptic in Education
Using this feedback,
the user receives tactile
response from
holograph as if it were a
real object. It is based
on using ultrasound
waves thereby creating
acoustic radiation
pressure. It is through
tactile response that
user percieves the
object.
Future Applications

28. Wearable Haptic Technologies
 Haptic Colthes
 Gripping
Gaming

29.  Doppel smartwatch - is
another slave to the haptic
rhythm, only its vibrations
are used to subtly alter the
wearer's mood with rhythmic
pulses; fast for energetic
spurts, slow for calming
moments.
 Slimming down - Novasentis
introduced with the wafer
thin haptic actuator it created
out of an electromechanical
polymer. "It's like a piece of
Wearable Haptic Technologies

30. Ultra haptic
. Ultrahaptics has developed a unique
technology that enables users to receive tactile
feedback without needing to wear or touch
anything. The technology uses ultrasound to
project sensations through the air and directly
onto the user. Users can ‘feel’ touch-less
buttons get feedback for mid-air gestures or
interact with virtual objects.

31. LIMITATIONS
 Hign cost involved
 Large weight and size of haptic
devices(especially wearable one)
 Haptic interfaces can only exert forces with
limited magnitude and not equally well in all
directions.
 Haptic rendering algorithms operate in discrete
time whereas user operate in continuous time.

32.  Implemented algorithms that are needed for
haptic rendering of a CSG tree.
 These algorithms make use of the same
representation as the graphical rendering
algorithms.
 These algorithms do not make any assumptions
on the primitives, other than that a primitive
renders its surface contact point in a correct
manner.
conclusion