THINK.FEEL.HAPTICS
Haptic technology is now evolving and coming out of research centers and into real products and solutions. We strongly believe Haptics are rousing the mainstream technology. We in GotouchVR rendered haptics into VR and for the past few years convincing clients to touch the imagination.
Haptic communcation is the way in which one communicates with another in a way of touch. Moreover with VR devices rendering haptics is the next generation methodology and here in GotouchVR we made it more simple and user- friendly. We believe this technology should reach everyone even the people who are not tech savy.
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By using external device called VRTOUCH users can receive feedback from applications with physical touch.
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The detection of collision or penetration is the primary step for most of haptic rendering algorithms. In general, solid objects are rendered by detecting the penetration point on the surface, computing the surface normal vector and scaling according to a given force
Our Haptic Rendering Architecture
Haptic rendering is the process in which the stimuli is imposed to a user to convey information of a virtual haptic object. Such information is the representation of object attributes, i.e. shape, elasticity, texture, mass, etc.
The collision detection block provides the contact information occurring between avatars and virtual objects. Force response block yields the interaction force, temperature, etc. between avatars and virtual objects. The control algorithm computes the force with respect to the capability of haptic devices. For instance, assuming the maximum force that a haptic device can give to a user is 1N, the force calculated by the force response block must be adjusted and restrained to be within 1N.
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Collision Detection
--if, how and when contacts happen
Collision detection is fundamental in VR. It detects whether, where and when a collision or contact occurs. It also determines the number of objects which collides. Collision detection is especially important in haptic rendering since it provides information for the computation of interaction forces.
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x(t) and F(t) are continuous-time position and force signals exchanged between users and haptic devices. x(k) and F(k) are discrete-functions.
Some simple algorithms:
1) Axis-aligned` bounding box: It is computationally expensive to verify if a point is inside an object(e.g. polygonal, polyhedra) by scanning all the coordinates of the object. Rather we compute an axis aligned bounding box (AABB) which encloses an object by its maximum and minimum coordinates on its X, Y and Z axis.
2) Orientated bounding box: The axis aligned bounding box is simple but not the optimum solution. Its edges of the box are parallel to the global coordinate axes making collision detection inaccurate. In orientated bounding box (OBB), the box edges adopt the local coordinate axes of an object, therefore, the box edge are fit to the object. Fig. 3 illustrates the difference between AABB and OBB
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Difference between AABB & OBB
3) Binary space partition: Binary Space Partition (BSP) is useful in terms of collision detection for multiple objects or a single object with multiple triangles. The space can be, therefore, divided into several regions with one region associated with an object or a group of objects. This architecture forms into a binary tree which can significantly decrement the searching time, since detection for some objects can be eliminated when its associated node is not collided .
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Binary space partition for collision detection
Rendering attributes
Texture and Stiffness Rendering
The attributes of objects incorporate temperature, stiffness, texture, etc.. We herein are only concerned with stiffness and texture.
Stiffness is the rigidity of an object which resists to deformation in response to an applied force. Stiffness rendering is widely utilized in medical simulation, such as simulation of soft tissues.
Texture rendering is composed of tactile and kinesthetic rendering. The simplest way to render texture is placing a point-based device in a 3D environment and calculating repulsing forces by varying direction and magnitude.
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One example of texture rendering: record the real-world texture information
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Recorded data: position, orientation, force, acceleration, etc
Frequency Mismatch
Frequency mismatch makes haptic rendering unstable.
•Refresh rate of graphic engine: 30Hz~60Hz
•Haptic device: 1kHz
Solutions:
• Multiple threads/processes
• Interpolation
• Virtual coupling etc.
Virtual coupling
•Intermediate layer between client & server
•Spring-damper system to exchange forces
•One spring-damper on both sides
•Forces computed on both sides
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In our products, frequency mismatch is no longer an issue
Cutting edge technology for VR Touch
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Interactions with your fingertips
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6 haptic devices working simultaneously
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Rendering either stiffness or texture
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Supports unity
We Deliver
•Not limited to fingertips, but can support a complete human body
•Support rendering different stiffness, texture etc. simultaneously
•Support other haptic hardware
•Support different game engines (e.g. Unity, Unreal)
•Provide solutions for haptic products
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