Browsing by Subject "Physically-based modeling"

Now showing 1 - 5 of 5

Open Access
Particle-based simulation of the interaction between fluid and knitwear
(2014) Güdükbay, Uğur; Bayraktar, S.; Koca, Ç.; Özgüç, B.
We present a particle-based method to simulate and visualize the interaction of knitwear with fluids. The knitwear is modeled using spring-mass systems and the fluid is modeled using the smoothed particle hydrodynamics method. Two-way coupling is achieved by considering surface tension, capillary, and interparticle forces between the fluid and knitwear. The simulation of fluid and knitwear particles is performed on the graphics processing unit. Photorealistic rendering of knitwear and fluid is achieved by using a hardware-accelerated rasterization-based rendering technique. Our method is able to simulate and visualize the macro- and microstructure of free-form knitwear and reflective and refractive characteristics of the fluid surface. © 2012 Springer-Verlag London Limited.
Open Access
Physically-based animation of elastically deformable models
(1994) Güdükbay, Uğur
Although kinematic modeling methods are adequate for describing the shapes of static objects, they are insufficient when it comes to producing realistic animation. Physically-based modeling remedies this problem by including forces, masses, strain energies, and other physical quantities. The behavior of physicallybased models is governed by the laws of rigid and nonrigid dynamics expressed through a set of equations of motion. In this thesis, we describe a system for the animation of deformable models. A spring force formulation for animating deformable models is also presented. The animation system uses the physicallybased modeling methods and the approaches from elasticity theory for animating the models. Three different formulations, namely the primal, hrjhrid, and the spring force formulations, are implemented so that the user could select the suitable one for an animation, considering the advantages and disadvantages of each formulation. Collision of the models with impenetrable obstacles and constraining model points to fixed positions iii space are implemented.
Open Access
Procedural visualization of knitwear and woven cloth
(Pergamon Press, 2007-11) Durupınar, F.; Güdükbay, Uğur
In this paper, a procedural method for the visualization of knitted and woven fabrics is presented. The proposed method is compatible with a mass-spring model and makes use of the regular warp-weft structure of the cloth. The visualization parameters for the loops and threads are easily mapped to the animated mass-spring model. The simulation idea underlying both knitted and woven fabrics is similar as we represent both structures in 3D. As the proposed method is simple and practical, we can achieve near real-time rendering performance with good visual quality. © 2007 Elsevier Ltd. All rights reserved.
Open Access
Towards practice real-time water simulations : multiphase smoothed particle hydrodynamics (M-SPH)
(2008) Gökdoğan, Göktuğ F.
Simulation of water and other fluid phenomena have always been a popular topic in the computer graphics research area and many solutions provided in this topic covers many fluid simulation aspects. However, with the complex nature of physics of fluid dynamics, usually these solutions are not applicable to the real-time domain, especially interactive applications like computer games. The solutions that both target a realistic behavior and real-time CPU boundaries tend to solve the problem by utilizing Smoothed Particle Hydrodynamics (SPH) technique in the solution of Navier-Stokes equations. In this study, we introduce a novel approach for modeling of the water dynamics with multiple layers of SPH. This approach increases the level of detail in the constructed water surfaces while decreasing the required overall computation time. To achieve this, an extra SPH layer is introduced to use larger particles to fill most of the fluid volume which helps to simulate general fluid behavior in less numbers while utilizing other extra SPH layers with small particles to fill up in-betweens for finer detail in water surfaces. The performance gain can be up to several magnitudes with the increase of the water size while maintaining visually similar or more appealing results.
Open Access
A virtual garment design and simulation system
(IEEE, 2007-07) Durupınar, Funda; Güdükbay, Uğur
In this paper, a 3D graphics environment for virtual garment design and simulation is presented. The proposed system enables the three dimensional construction of a garment from its cloth panels, for which the underlying structure is a mass-spring model. The garment construction process is performed through automatic pattern generation, posterior correction, and seaming. Afterwards, it is possible to do fitting on virtual mannequins as if in a real life tailor's workshop. The system provides the users with the flexibility to design their own garment patterns and make changes on the garment even after the dressing of the model. Furthermore, rendering alternatives for the visualization of knitted and woven fabric are presented. © 2007 IEEE.