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"Elastic Object Model" started in 1994 and continues. It is the longest running project among other projects in the laboratory. Physically-based methods were very popular for constructing realistic motion animation in the early 90's. Our theme was to apply physically-base methods to real-time interactive applications. Elastic objects were constructed by mass points and springs, and motion was derived by the Eular method, a numerical integration solution. Its advantage is fast computation which is suitable for real-time processing and simple programming implementation is made easily. However, when an object is strongly deformed, the body shape of the object can't be kept consistently or behavior becomes abnormal.
In the first term of the study (1994 - 1997), spring specification was improved from a simple linear elasticity model to a mixtured one with rigidity and elasticity. This model improved shape consistency in the above problem, but this solution was not suitable for soft elastic object expression because it constrained deformation by introducing rigidity.
In the second term (1997 - 2000), springs, that are elastic primitives in mass-and-spring models, are expanded to volumetric elastic primitives. It is a 'local shape maintaining model'. In this model, restoration force was defined to maintain the original shape of the primitive. It has both advantages, simpleness of mass-and-spring model and properness of elastic force definition in the finite element method (FEM).
In the current term (2000 - 2002), our main purpose is acceleration of motion computation by reducing the number of elements. Roughly speaking, small elements are located on the surface of the object and large ones in the center. It generates exact deformation on the surface and reduce computation time in other parts, in return for rough motion generation. Our future works are to develop practical-use applications.
| obstacle.h | wall and manipulator class |
| voxeldata.h | voxel data class |
| vertex.h | vertex information class |
| element.h | elastic element information class |
| joint.h | joint information class among vertices |
| voxelbody.h | fundamental voxel model class |
| gradation.h | gradation model class derived from the voxel model |
| destruction.h | destruction model class derived from the gradation model |
| mainx.cpp | event-driven functions |
| em-gl.zip | OpenGL+ freeGLUT version for VC++.Net and Linux * |
| em-dx.zip | DirectX9 version for VC++.Net (Joystick Version)** |
* Mesa 3D and freeGLUT
have to be installed beforehand.
** DirectX 9.0b SDK has to be installed beforehand.
| em.exe (364k) | Executable for Windows * |
| freeglut.dll (392k) | Save in the same directory as "em.exe". * |
| em (206k) | Executable for Linux |
Manipulator is controlled by dragging a mouse.
* "freeglut.dll" is necessary to execute em.exe.
Modelling and Implementation of Elastic Object Manipulation in Virtual Space
Miyazaki S, Yasuda T, Yokoi S, Toriwaki J
Electronics and Communications in Japan Part 3: Fundamental Electronic Science, pp.1919-1926, 1998.1
A Study of Virtual Manipulation of Elastic Objects
Miyazaki S, Yasuda T, Yokoi S, Toriwaki J
Computer Graphics: Developments in Virtual Environments (Proc. Computer Graphics International'95),
Leeds, pp.381-391, 1995.7
A Study of Virtual Manipulation of Elastic Objects with Destruction
Miyazaki S, Ueno J, Yasuda T, Yokoi S, Toriwaki J
Proc. IEEE International Workshop on Robot and Human Communication '96, Tsukuba, pp.26-31, 1996.11
A Deformable Object Model for Virtual Manipulation Based on Maintaining Local Shapes
Miyazaki S, Hasegawa J, Yasuda, T, Yokoi S
Proc. SCI2001, Orlando, 2001.7
Simulation of Human Motion - Using Tissues Represented by Elastic Object Models
Inaba H, Miyazaki S, Taki T, Hasegawa J
Proc. SCI2001, Orlando, 2001.7
Muscle-driven motion simulation based on deformable human model
constructed from real anatomical slice data
Inaba H, Miyazaki S, Hasegawa J
Proc. AMDO2002, Palma de Mallorca, 2002.11
Acceleration of Elastic Model's Motion Computation Based on Elastic Element Reduction
Miyazaki S, Hasegawa J, Yasuda T, Yokoi S
Advances in Modelling, Animation and Rendering (Proc. Computer Graphics International 2002),
Bradford, pp.239-246, 2002.7
Cooperative Elastic Object Manipulation Performed by Virtual Joystick Operation
Suzuki S, Endo M, Yamada M, Miyazaki S, Hasegawa J, Yasuda T, Yokoi S
Proc. VSMM2004, 2004.11
A Deformable Fast Computation Elastic Model Based on Element Reduction and Reconstruction
Miyazaki S, Endo M, Yamada M, Hasegawa J, Yasuda, T, Yokoi S
IEICE Transaction on Information and Systems, Vol.E88-D, No.5, pp.822-827, 2005.5.
A Deformable Fast Computation Elastic Model Based on Element Reduction and Reconstruction
Miyazaki S, Endo M, Yamada M, Hasegawa J, Yasuda T, Yokoi S
Proc. Cyber World 2004,
Tokyo, 2004.11