Earlier this year, Matthias Müller-Fischer, PhysX SDK Research Lead in NVIDIA, has presented new universal solver that can be used simulate almost any kind of objects – rigid, plastic, cloth or soft body.

You can familiarize with this work via previously published research papers: Solid Simulation with Oriented Particles and Adding Physics to Animated Characters with Oriented Particles.

Today, interesting video was revealed – it is showcasing impressive 20x performance improvement for this type of simulation running on GPU through CUDA, in comparison to CPU execution (5 “Lionfish” objects on CPU vs 100 on GPU – in real-time).

Sometimes findings of PhysX Research team are incorporated in PhysX/APEX products, and sometimes, for various reasons, they just become a research paper or presentation. We hope that in case with solver there will be only one option – first one.

Another interesting research paper was published by Dr. Matthias Müller-Fischer, PhysX SDK Research Lead in NVIDIA.

Update: Oriented Particles solver through CUDA

It is called Adding Physics to Animated Characters with Oriented Particles and it further expands oriented particles approach with techniques for simulation of clothing on animated characters.

Abstract:

We present a method to enhance the realism of animated characters by adding physically based secondary motion to deformable parts such as cloth, skin or hair. To this end, we extend the oriented particles approach to incorporate animation information. In addition, we introduce techniques to increase the stability of the original method in order to make it suitable for the fast and sudden motions that typically occur in computer games. We also propose a method for the semi-automatic creation of particle representations from arbitrary visual meshes. This way, our technique allows us to simulate complex geometry such as hair, thick cloth with ornaments and multi-layered clothing, all interacting with each other and the animated character.

Two new research papers have landed on a homepage of Dr. Matthias Müller-Fischer, PhysX SDK Research Lead in NVIDIA and NovodeX co-founder.

Fisrst one, called “Real-Time Eulerian Water Simulation Using a Restricted Tall Cell Grid“, presents further impovements to the real-time hybrid fluid solver, that we were able to see in recent demos like Lighhouse and Raging Rapids Ride.

Abstract:

We present a new Eulerian fluid simulation method, which allows real-time simulations of large scale three dimensional liquids. Such scenarios have hither to been restricted to the domain of off-line computation. To reduce computation time we use a hybrid grid representation composed of regular cubic cells on top of a layer of tall cells. With this layout water above an arbitrary terrain can be represented without consuming an excessive amount of memory and compute power, while focusing effort on the area near the surface where it most matters. Additionally, we optimized the grid representation for a GPU implementation of the fluid solver.

To further accelerate the simulation, we introduce a specialized multigrid algorithm for solving the Poisson equation and propose solver modifications to keep the simulation stable for large time steps. We demonstrate the efficiency of our approach in several real-world scenarios, all running above 30 frames per second on a modern GPU. Some scenes include additional features such as two-way rigid body coupling as well as particle representations of sub-grid detail.

We badly want to see this one in further releases of PhysX SDK 3 or APEX.

Read the rest of this entry »

Interesting paper, called “Scalable Fluid Simulation using Anisotropic Turbulence Particles” has appeared at homepage of Dr. Markuss Gross, from ETH Zurich.

As far as we know, same solver is used in APEX Turbulence module.

Abstract:

It is usually difficult to resolve the fine details of turbulent flows, especially when targeting real-time applications. We present a novel, scalable turbulence method that uses a realistic energy model and an efficient particle representation that allows for the accurate and robust simulation of small-scale detail. We compute transport of turbulent energy using a complete two-equation k–e model with accurate production terms that allows us to capture anisotropic turbulence effects, which integrate smoothly into the base flow. We only require a very low grid resolution to resolve the underlying base flow.

As we offload complexity from the fluid solver to the particle system, we can control the detail of the simulation easily by adjusting the number of particles, without changing the large scale behavior. In addition, no computations are wasted on areas that are not visible. We demonstrate that due to the design of our algorithm it is highly suitable for massively parallel architectures, and is able to generate detailed turbulent

In addition, this paper comes with nice video demonstration (92 mb). It is worth to watch.

Thanks to AquaGeneral for the link.

Interesting research project, called pCubee – five-paneled LCD cube that gives users the appearance that virtual objects are inside and product of two years of work by students at the University of British Columbia – has drawn our attention recently. Why ? Because software part of pCubee is based on Open Scene Graph and PhysX SDK.

As you may see, pCubee can handle not only simple rigid bodies collisions, but also more complicated objects, like softbodies (1:20 – 1:27) and particle systems.

Gonna be interesting to see if this project will evolve from concept to something more consistent, like game console or other consumer entertainment product.