4 results
Search Results
Now showing 1 - 4 of 4
Item Rigid Body Joints in Real-Time Unified Particle Physics(The Eurographics Association, 2018) Lovrovic, Bojan; Mihajlovic, Zeljka; Diamanti, Olga and Vaxman, AmirIn this paper, we propose a physically-based method for a rigid body joint simulation. The proposed solution is based on the unified particle physics engine, a simulator that uses only particles for all the dynamic bodies. Such engines are implemented on the GPU and they simulate fluids, rigid bodies or deform-able materials like cloth or ropes. To support more complex systems like skeletal simulation, we show a joint implementation that is intuitive and unique to this environment. Four types of joints will be shown, as well as the necessary details about the rigid body data structure. This will enable the construction of a popular method called ragdoll. Lastly, a performance measurement and a comparison with alternatives will be given.Item Reduction of CPU-GPU Synchronization Overhead for Accelerating Implicit Clothing Simulator(The Eurographics Association, 2018) Lee, Sangbin; Ryu, Donghan; Ko, Hyeong-Seok; Diamanti, Olga and Vaxman, AmirWhen trying to make the conjugate gradient (CG) method exploit GPU technology, this paper notes that the communication between CPU and GPU to transfer the residual value and waiting for the CPU's decision whether to continue further iterations is a new source of delay that has been overlooked and turns out not negligible. By examining the residual decrease pattern in log scale, this paper proposes so-called the Secant Lazy Residual Evaluation (Secant LRE) method to skip needless synchronization. We experimented the method for a clothing simulator and found that the proposed method reduces the sync overhead significantly, leading to 10 60% performance gain.Item Time-Reversed Art Directable Smoke Simulation(The Eurographics Association, 2018) Oborn, Jeremy; Flynn, Sean; Egbert, Parris; Holladay, Seth; Diamanti, Olga and Vaxman, AmirPhysics-based fluid simulation often produces unpredictable behavior that is difficult for artists to control. We present a new method for art directing smoke animation using time-reversed simulation. Given a final fluid configuration, our method steps backward in time generating a sequence that, when played forward, is visually similar to traditional forward simulations. This allows artists to create simulations with fast turnaround times that match an exact art-directed shape at any timestep of the simulation. We address a number of challenges associated with time-reversal including the problem of decreasing entropy.Item Expressive Curve Editing with the Sigma Lognormal Model(The Eurographics Association, 2018) Berio, Daniel; Leymarie, Frederic Fol; Plamondon, Réjean; Diamanti, Olga and Vaxman, AmirWe describe a practical application of the Sigma Lognormal model of handwriting movements for computer graphics applications that require the interactive or procedural definition of artistic or calligraphic traces. The method allows to easily edit curves with physiologically plausible kinematics that can be exploited in order to generate expressive brush renderings, natural looking stroke animations and easily generate stylistic variations of a trace.