My Research

Abstract: In this paper we discuss the technique of performing Quadruped Motion Analysis from the original video footage of quadruped character in motion. The motion analysis involves calculating the footfall patterns and plotting the diagram, along with generation of Motion Gait Graphs for each leg showing the swing and stance phase of each leg in motion. The developed hybrid system for procedural animation proposes the use of Inverse Kinematics along with Dynamic Controllers .The desired motion control input, comes either from the user or from a higher level motion planning system. A motion planning system uses the gait graph and footfall pattern information to produce the desired animal behavior. In our case, the motion control input consists of the desired values for the body’s velocity, and the heading determined by the yaw angle. The dynamic controller computes the aggregate force Fr and torque Tr that should be applied to the body at the center of gravity. The problem can be formulated as a linear constrained minimization and is solved using the Simplex method for linear programming. The leg subsystem is controlled by the kinematic gait controller. Based on these forces, a forward dynamic simulation is performed to compute the new state of the body.

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Zeeshan Bhatti, Asadullah Shah, "Motion Analysis and Procedural Animation of Quadruped Character using Hybrid Model”, Poster, Proceedings of Third Postgraduate Students Colloquium (PGSC) 2013-2014, at KICT, International Islamic University Malaysia. 3rd October, 2013. (Won BRONZ Medal)

In this paper, a procedural model has been developed for synthesizing cyclic horse motion through trigonometric functions. The system has been developed and implemented using mathematical model derived from trigonometric cyclic equations, along with forward and inverse kinematics, motion dynamics and gait error optimization to produce absolute gait control over the locomotion of horse character. The dynamic motion is calculated independently for each body part with GUI based user interaction and control over the speed, frequency and oscillation during runtime, for high divergence control over the simulation. The user can manipulate the simulation parameters for motion speed, body oscillation, leg impact phases and duration at runtime and our system will automatically adjust the motion of horse and gait transition according to the user input. At preprocessing level a template based horse skeletal rig is generated automatically with inverse kinematics (IK) controllers for the spine, neck and all four legs. The head, tail, and feet’s are controlled with forward kinematics (FK), along with scapula and sternum joints of the legs. Motion cycle is generated using the stance time and leg cycle time. Our procedural model for horse simulation can currently generate various gaits of motion with variable speed and body oscillation with controllable behavior and transaction of gaits at runtime.

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Zeeshan Bhatti, Asadullah Shah, Farruh Shahidi, ”Procedural Model of Quadruped Simulation”, Poster, Proceeding of Invention and Innovation Exhibition (IRIIE 2013) organized by International Islamic University Malaysia (IIUM), held at CAC, IIUM Malaysia 2013. (Won SILVER Medal)

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Zeeshan Bhatti, Asadullah Shah, Farruh Shahidi, ”Procedural Model of Horse Simulation”, Poster, Proceedings of Second Postgraduate Students Colloquium (PGSC) 2012-2013, at KICT, International Islamic University Malaysia. 14th December 2012. (Won BRONZ Medal)

The animation of articulated quadruped (four legged) objects such as Horses or Lions poses a major challenge because of the many degrees of freedom and range of possible movements involved. Key-framing – being the traditional technique provides support only at a low level- the animator tediously creates various control rigs to control and manipulate joint angles or coordinates for each bone type and its degree of freedom. The process of animating a character from pose to pose through key-framing may seem simple in application but in practice is quite tedious, long and grim, especially when animating quadrupeds. Achieving the accurate realistic timing curve is a difficult and daunting task for an animator. The use of Second animation technique - motion capture (mocap) also possesses difficulties and problems. From the cost of the mocap equipment, to technical understanding of the system at hardware level and then implementation issues in an 3D environment, make it a very difficult and tedious process. In my research I aim to work on developing a system which will make animating quadrupeds a very stress-free and automated process through the use of procedural animation. In order to simplify and automate the process of character animation, I purpose the use of higher level technique called procedural animation where mathematical expressions and models can be used to achieve automated movements and animation of these various characters types, hence creating realistic looking animation easily and quickly. Through mathematics exact locomotion of character gaits, knowledge about particular motions or motion processing aspects can be directly incorporated into the control algorithms to achieve accurate timing curves. Then using these algorithms, the entire process of animating a virtual character of various types such as Horses, Lions and Dogs can be simplified and automated.

The process of animating a character from pose to pose through key-framing in practice is quite tedious, long and grim process, especially when animating quadrupeds (animals with four legs). Achieving the accurate realistic timing curve is a difficult and daunting task for an animator. Through this research the problem of generating involuntary and accurate animation of quadrupeds with automatic rigging system of various character types will be solved, allowing a two tier animation control curve with base simulation being driven through dynamic mathematical model using procedural algorithm and the top layer with a custom user controlled animation provided with intuitive graphical user interface (GUI). The User will be given various manipulators and attributes to control and manipulate the locomotion gaits of the characters and choose between various types of simulated motions from walking, running, trotting, ambling, galloping, turning, sitting down and standing up, with complete custom controls to easily extend the base simulation as per requirements. For the initial controller based dynamic simulation generation, the mathematical model driven uses internal virtual forces computed through Jacobian Transpose and summation has been applied with Proportional Derivative controllers for gait graphs, independent leg frames with multi joint spine model and neck model.

The major objectives of this research are as follows:

i) To develop an automatic rigging system of various character types with forward and inverse kinematics for advance animation and custom control by the user.

ii) To develop a Procedural system based on mathematical model for generating motion dynamics with multiple gates and locomotion’s involving walking, running, trotting, ambling, galloping, turning around, sitting down and standing up.

iii) To develop an integrated plugin system that provides complete customization of the various simulations through an easy to use Graphical User Interface (GUI).

iv) To develop an auto testing mechanism to test the operational functionality of the characters skeletal and control rigs, along with the accuracy of procedurally generated simulations using gait graphs and timing charts.

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BHATTI, Z., SHAH, ASADULLAH, K. M., AND MAHESAR, W. 2013. Expression driven trignometric based procedural animation of quadrupeds. In Proceedings of the International Conference on Informatics and Creative Multimedia 2103 (ICICM’13), IEEEXplore.

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Bhatti Zeeshan, Shah Asadullah , Shahidi Farruh, “Procedural Model for Horse Simulation”,Proceedings of 11th ACM SIGGRAPH International Conference on Virtual-Reality Continuum and its Applications in Industry (VRCAI 2012), pages 337-340. (Paper Accepted)

Character rigging is a process of endowing a character with a set of custom manipulators and controls making it easy to animate by the animators. These controls consist of simple joints, handles, or even separate character selection windows. In this research paper we present an automated rigging system for a humanoid (biped) character with complete customization and control options according to the need of the character rigger and the animator. The rigging requirements check list has been proposed for each body part by analyzing various live natural human motions and then summarizing them. The system initially provides widgets that represent human skeletal joints, which can be easily manipulated and modified according to the character type and body height. The system takes the widgets positions from the 3D space and creates the joint based skeletal structure automatically using procedural programming and then followed by creating a complete bipedal rig with custom manipulators to satisfy the animators need in a production environment.

Majority of the research successfully generates the skeleton of any given mesh through various techniques and the use that skeleton for animating the character through motion capture data or procedurally driven motion. The problem concerns the real life production environments where the animator uses the manually rigged character with custom controls and manipulators to create the animation, and thus the auto generated skeleton becomes practically unusable by the animator.

In this research work we use a template based skeletal generation mechanism called widgets, for bipedal character based on the actual human anatomy. Then this skeleton is automatically rigged according to the various standards and criteria researched and discussed with custom controls and manipulators. This system of automation will provide a practical solution to the real life problem of character rigging and animation.

The proposed system of automated rigging of biped character with custom manipulators, removes this boredom from the character riggers. This is achieved by producing the bipedal character rig automatically with all custom selection controls with inverse kinematics (IK) and forward kinematics (FK), thus making the process of rigging a stress free and timesaving. This system will facilitate the novice character rigger and animator greatly by simple clicking on few buttons and they will have their rig created and ready for animation.

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Zeeshan Bhatti, Asadullah Shah, 2012, “Widget based Automated Rigging of Bipedal Character with Custom Manipulators”, Proceedings of 11th ACM SIGGRAPH International Conference on Virtual-Reality Continuum and its Applications in Industry (VRCAI 2012), pages 337-340. ACM Press. ACM, New York, USA,. Dec 2-4, 2012. [pdf][Link]

In proposed research work an attempt has been made to develop a Sindhi Word Spell Checker system which transparently checks each Sindhi word (combination of characters and ligatures) for any spelling mistakes as it is entered in a Sindhi software and provide correct spelling suggestions as alternate words in place. The application is integrated as a utility with recent Sindhi word processing developments and as a plug in patch application for other compatible Sindhi word processing software i.e. MS. Office. An auto correction feature is integrated with the system for identifying different patterns of spelling mistakes, most commonly made mistakes and correcting those error automatically without any user action. The system is able to identify and report various types of spelling mistakes for instance the following spelling and typo errors possibly experienced in Sindhi drafting composition:

o Spelling Mistakes

o Letter transpositions

o Inadvertent spaces between parts of words

o Accurate identification and correction of Sindhi ligatures.

o Intelligent treatment of phrases.

Additional features have been investigated for making the system user friendly, need to have options allowing the user to incorporate the words into a database, not already in data dictionary. The undertaken research work as far as we know is a lead in designing an automated Sindhi Word Spell checker.