Autodesk and NVIDIA continue their effort to create the universal physics simulation system for 3ds Max package – it is known as MassFX.

What has changed in new MassFX version, that comes with 3ds Max 2013, in comparison to the first release? We have tried to answer this question in our review.

One of the main new features of MassFX 2013 is the addition of mCloth – cloth simulation module, which was co-developed with Autodesk. Despite the rumors, mCloth uses PhysX 2.8.4 cloth solver for underlying physical calculations.

In comparison to APEX Clothing tools in PhysX plug-ins, mCloth is clearly oriented on VFX area: “one click” set up (no need to skin the mesh and apply movement constraints, as for APEX), full collisions with MassFX rigid bodies with two-way interaction, vertex group operations (like pin or attach to object), support for dynamic and kinematic cloth, ability to bake the simulation in keyframes.

Desired cloth behavior can be archived by tuning fabric settings, like density or damping, which can be saved and loaded as presets.

Additional parameters include rigid body collision responce and solver precision settings.

mCloth objects support per-vertex tearing.

Interesting option is ability to visualize material tension within given treshold.

Another feature is so-called “ballon behavior” – closed meshes can be inflated with internal pressure to imitate soft body, jelly-like objects or baloons themselves.

However, if hole in the baloon will be detected (as result of tearing, for example), it will deflate and force will be applied to the point of air outflow.

“Hardware acceleration” option can be enabled for cloth simulation, however, we were not able to spot any performance difference between CPU and “GPU” execution. It seems GPU acceleration is not fully operational yet.

To summarize: mCloth is a strong cloth simulation solution with decent pack of features and sufficient artist control over simulation, however, as a new tool it has not avoided some “childish” problems, like nonoptimal baking process (it is significantly slower than sim in viewports), unstable behaviour of baloon objects or overestimated cloth solver settings (they are set automatically, based on mesh resolution, but for real 3-5 times lower values are sufficient).

Another vital new feature – standart Forces (like PBomb, Vortex or Wind) can now affect MassFX objects, both rigid bodies and cloth.

Being developed in Autodesk, Forces interaction feature is not using forcefields mechanism from PhysX SDK, instead, custom forces are applied directly to actors.

Third major addition – stable auto-generated ragdolls from biped skeletons.

Instead of abomination – jiggling mess of rigid bodies and joints – that may be familiar you from original PhysX plug-ins, “create dynamic ragdoll” option now generates fairly adequate ragdolls, usable even without aditional tuning.

Note: unlike latest PhysX plug-ins, MassFX is only using one version of PhysX engine - 2.8.4.

Apart from all the features described above, MassFX 2013 also contains numerous amount of smaller features, interface changes and bug fixes. Here are some examples:

It is now possible to assign gravity to Forces (or even it completely) through MassFX Toolbar.

Convex decomposition (this tool allows MassFX to support concave objects) has been reworked – it is now using simplified interface and operates faster.

Physical meshes can now be displayed not only as wireframe, but as shaded hulls as well.

Multiple constraints can now be adited at the same time via Multi-object Editor tab (previosly only available for rigid bodies).

And.. more !

To summarize: MassFX has grew up, but still not enough to reach level of Reactor’s feature set. However, with continuing support from Nvidia and Autodesk, MassFX will eventually overcome previous solution from Havok.

Finally, NVIDIA has officially presented their new GPU – GTX 680, built on 28nm GK104 chip, which itself is based on next-gen Kepler architecture.

Many rumors were floating around Kepler and its physics acceleration capabilities, some were endowing new GPU with dedicated PhysX blocks, others were claiming ability to run CPU PhysX games in hardware – none of this happens to be true. Nothing special (like NVENC video encoder) for physics calculations, just general improvements to chip architecture, SM clusters, etc.

Nonetheless, we will try to gather all available information regarding PhysX computation performance of the GTX 680, in comparison to previous generation GPUs.

NVIDIA Kepler GPU GeForce GTX 680 Video Card Review by HARDOCP

Interesting results – in this case, GeForce GTX 680 performance is higher than Radeon HD 7970 even with GPU PhysX effects enabled. However, we can not directly compare GTX 580 and GTX 680 due to different resolution settings.

NVIDIA GeForce GTX 680 (Kepler) by HardwareHeaven

At lower resolutions situation is quite different – enabled PhysX acceleration introduces significant penalty to GTX 680 performance.

NVIDIA GeForce GTX 680 Review by Eurogamer

GTX 680 is showing 15% performance improvement over its predecessor, but again on medium PhysX settings only.

Test: Nvidia GeForce GTX 680 by ComputerBase

GTX 680 vs GTX 580: similar results in Dark Void Benchmark (only “PhysX Low” settings are used – simple particle effects) and significant performance difference in Mars Benchmark (which contains more diverse PhysX content like fluids, particles and tearable cloth, but also produces very disputable results).

Nvidia’s GTX 680 arrives! “Faster, Smoother, Richer” by Alienbabeltech.com

Most comprehensive set of PhysX benchmarks comes from Alienbabeltech ! According to their numbers, average PhysX performance difference between GTX 680 and GTX 580 is around 11 %. Not as impressive as one might expect, huh?

Note: surpisingly, from several dozens of GTX 680 reviews we were able to find, only a few are containing actual PhysX benchmarks, majority of the reviewers just leave hardware acceleration disabled.

Update: more benchmarks !

GTX 680: PhysX and CUDA Testing by Playwares.com

First article where GTX 680 is tested as dedicated PhysX card – in this case, framerate is 17% better than with dedicated GTX 580.

(PhysX Test) GTX 680 vs GTX 580 vs GTX 480 in FluidMark by Geeks3D

In a synthetic test like FluidMark, GTX 680 shows decent PhysX performance.

Certainly, many of you will agree that the addition of GPU PhysX effects to PC games has a positive influence on overall gaming experience and immersion in such titles. But how difficult is to attach hardware accelerated physics effects to a game?

Today, with the help of David Schoemehl, Manager of GPU PhysX Content in NVIDIA, and Johnny Costello, Technical Artist, we will try to give you a brief “behind the scenes” view on the process of enhancing games with extra PhysX content.

PhysXInfo.com: Hi, Johnny and David. Can you please introduce yourself?

Johnny Costello: My name is Johnny Costello, I’m 29 years old and am a native to the Midwestern United States. I went to college at Savannah College of Art and Design and received my B.F.A. in game development. I have been a technical artist at NVIDIA for about two and a half years. During that time I have worked on several GPU PhysX titles such as Batman: Arkham Asylum, Batman: Arkham City, Mafia II, Dark Void, and Alice: Madness Returns.

David Schoemehl: My name is David Schoemehl, I joined AGEIA in 2006 as an applications engineer and was the project manager on Warmonger. Since the purchase of AGEIA by NVIDIA in 2008 I have led or supported several shipping GPU PhysX titles and demos including Batman: Arkham Asylum, The Samaritan Demo, Sacred 2, The Great Kulu Demo, and Alice: Madness Returns.

My current title is Manager of GPU PhysX Content and I am responsible for aligning NVIDIA’s engineers and artists to support developers on GPU PhysX engagements. I also work closely with Epic Games to ensure a solid integration of GPU PhysX/APEX features in UE3.

PhysXInfo.com: Johnny, what is your task as a PhysX technical artist?

Johnny Costello: My tasks can change a lot from day to day, but usually I’m working on a game title in some capacity. Our goal at NVIDIA is to provide the tools that developers need in order to add great GPU features to their games. So I spend much of my time working with developers to help guide them as they use our technology to create exciting content.

Depending on the structure of a particular engagement I may also work alongside the developer to create GPU PhysX content. Then there are other days where I help design and review our tools and production workflows.

PhysXInfo.com: So what is in the process of adding GPU PhysX effects to a game?

Johnny Costello: We usually start by getting a build of a game and playing through it in its current state. We also read any available design and art documents to familiarize ourselves with the gameplay mechanics and the aesthetic style. From there, we identify any story events, environment locations, special effects, characters, etc. that could be enhanced with our feature set and make the game more fun to play.

From there, we work with the developer to refine this list and plan out a timeline. After that, it’s all about creating content with our tech that players will enjoy.

Once the content gets in the game, it starts getting reviewed by QA. We usually spend our time at the end of a title engagement addressing any bugs that QA has found and making minor content adjustments.

APEX Toolset helps artists to create content more easily

PhysXInfo.com: Users are often complaining that extra PhysX effects are not optimized properly for CPU execution (not using multiple cores, for example). What is the reason behind this?

David Schoemehl: This is a legacy issue regarding PhysX versions prior to 2.8.4. With proper setup it is possible to achieve some threading on PhysX 2.8.4, for instance running multiple cloth simulations in parallel. However, the overall threading performance issues have been addressed in PhysX 3, which is available today. With PhysX 3 we have improved the rigid body, clothing, and particle pipelines to take better advantage of multiple CPU cores.

PhysXInfo.com: Also, there is an opinion that with disabled GPU PhysX option, minor effects (like sparks or cloth banners) are omitted from the games on purpose, while they can be easily calculated on CPU or substituted with non-physical objects. What can you say about this?

David Schoemehl: When NVIDIA engages with a developer to work on a GPU PhysX title we will offer suggestions for enhancing existing effects and adding entirely new effects. For the existing effects that are enhanced by PhysX you will see original version of the effect with GPU PhysX disabled. For effects that are created new as part of the GPU PhysX effort you will not see a fallback, because it did not exist in the original game.

Our goal is to work with developers to enhance their original game to take advantage of the latest hardware NVIDIA has to offer. We want to provide gamers that select NVIDIA a superior play experience for these games. We would not want to raise the min recommended specs for a game determined by the developer by adding additional default effects to the original game.

PhysXInfo.com: You work closely with developers – is exclusivity of GPU PhysX content to NVIDIA some kind of a barrier for PhysX adoption? In other words, are developers interested in OpenCL / DX Compute version of PhysX engine?

David Schoemehl: No, we have not seen this as a blocker for PhysX adoption in general. PhysX provides a strong set of core physics engine functionality across a wide array of platforms including PCs, consoles, and mobile devices. PhysX powers game engines such as UE3 and Unity, and can be found in many of the AAA titles that are shipping today.

PhysX 3 addresses memory, threading, and performance concerns, which should further increase the adoption rate of PhysX. In addition to this core functionality, PhysX and APEX offer hardware acceleration for certain features, such as particles, cloth, rigid bodies, and turbulence, through CUDA. This is a powerful value add but does not interfere with developers using core PhysX and APEX features.

PhysX engine can be found in many AAA titles

PhysXInfo.com: What is your impression on NVIDIA APEX toolset? Is it really simplifying process of adding PhysX effects to games?

Johnny Costello: I definitely think so. For example, look at where we’re heading with APEX tools like PhysXLab and the Clothing plug-in for 3dsMax and Maya. They are becoming more robust with each release and are definitely making it easier to create APEX content for games.

One of my favorite things about PhysXLab is the Playground Mode where you can preview how your mesh is going to fracture in real time before bringing it into a game engine and placing it into a map. This saves valuable time between making parameter changes and seeing those changes visually affecting the fractured mesh.

PhysXInfo.com: You have probably already worked with the new clothing simulation engine, introduced in PhysX 3. How well does it performs in comparison to current one?

Johnny Costello: The PhysX 3 clothing engine gives us a stronger set of features. More attributes allow the artists and animators to make better aesthetic choices regarding their cloth. One of these new features is the ability to created tapered capsule collision shapes. These shapes allow the artists and animators to create a collision representation that is more true to the characters silhouette.

The new system also allows for more reliable behavior during intense, fast-moving, animation sequences. In addition to these features, overall performance has been improved allowing developers to use clothing across more platforms.

PhysXInfo.com: What additional features you would like to see in APEX, as a technical artist?

Johnny Costello: As a technical artist, I spend a lot of time trying to decompose exciting artistic ideas down into their components so they can be created in games. What I’m looking forward to in the future with APEX is seeing various features come together for a combined effect.

What happens when turbulent dust is spawned when a destructible is fractured? Can a character’s clothing move when it gets hit with particles? I can’t wait to see all these things come together to make games even more dynamic and intense for players to experience.

Unreal Engine 3 includes robust PhysX Particle System

PhysXInfo.com: We have noticed that recent GPU PhysX titles, like Alice: Madness Returns or Batman: Arkham City are not using APEX Particles but built-in PhysX particles system instead – why is that? Isn’t the Particles module more effective?

David Schoemehl: Both of these games are built using UE3, which already had a robust particle editor using NVIDIA’s GPU PhysX particles. APEX provides some great features for particle systems but for these cases UE3 was already providing the functionality we needed.

APEX Particles are a win if you are stepping into project that doesn’t already have an existing PhysX particle pipeline or if you are interested in doing some simulations, such as turbulence, which require a great number of particles that don’t require the high-fidelity collision of PhysX particles.

PhysXInfo.com: Dark Void was the only title to impress us with awesome Turbulence smoke, why much newer games are still using good old SPH method for smoke and fog simulation?

David Schoemehl: The turbulence in Dark Void was added as a one-off feature for that specific game so that we could see how it would show in a game. While we feel that turbulence was an awesome feature we have been focused on improving APEX Clothing and Destruction, because that is what developers were telling us they needed.

However, we are pleased to say the APEX Turbulence module is now scheduled for the APEX 1.2 release in Q2 of this year. So we hope to see it appear in many games in the future.

PhysXInfo.com: Mafia II was the first title containing APEX Clothing engine. Do you think this “benefice” was successful? What difficulties have you faced during development?

David Schoemehl: Yes, the work done in Mafia II was invaluable for clothing. We learned so much about how to improve the tools and features for clothing from the work done on this game. The payoff was visible in later titles such as Batman: Arkham City where the time to create clothing and get it in game was drastically reduced.

Mafia II: first game to utilize APEX Clothing module

PhysXInfo.com: Batman: Arkham City also seems to be using APEX Clothing pretty extensively. Is it true that Clothing module is utilized not only as part of PhysX effects, but also for non-GPU accelerated clothing simulation, even on consoles?

David Schoemehl: It is true that clothing can be run on the GPU, CPU, and even consoles. However, for Batman APEX Clothing can only be seen on the PC running on either the CPU or GPU. It should be noted that APEX Clothing was also used for some hair simulation in the pre-rendered cutscenes that can be seen across all platforms.

Clothing performance on consoles is something which we have been focusing on improving with the PhysX 3 and APEX Clothing effort. We are seeing an increase in the number of developers wanting to get APEX Clothing into their console games so I would expect to start seeing this soon.

PhysXInfo.com: One of the most vibrant effects in both Batman titles – scenes containing GPU Rigid Bodies. How has this technology evolved since Arkham Asylum?

David Schoemehl: To be clear, GPU Rigid bodies were only featured in Batman: Arkham Asylum. They were not used in Batman: Arkham City. However, we have been making great progress with GPU Rigid Bodies with regards to performance and simulation stability.

They were last featured in the APEX Art Gallery demo [link] at GDC 2011, and they will be available to the public in APEX 1.1 very soon.

PhysXInfo.com: Another interesting scene – physically simulated banknotes in a bank vault. Are those all individual cloth pieces? How many of them are there?

Johnny Costello: Yes, those are all APEX cloth. During production, that was a really neat scene to watch come together. Initially we weren’t sure if the player would be able to see the characters interacting with the dollar bills since they are so small, so we added forcefields to Catwoman’s animations, and then the scene came alive in a big way.

It is definitely one of my favorite fights in the game. There were about 500 individual bills in that scene, which adds up to approximately 10,000 simulating vertices of APEX cloth.

Around 500 bills are scattered on the floor

PhysXInfo.com: You have worked on many GPU PhysX games, but which one is your favorite?

Johnny Costello: I have great memories of all of the game engagements that I’ve been involved with, but working on the Batman series has probably been the most memorable experience for me. I’ve been a Batman fan since I was a little kid, and I basically joined NVIDIA in 2009 and immediately started working on Batman: Arkham Asylum. That was pretty amazing.

And then I had the opportunity to work on Arkham City! I feel very lucky to have been involved with both.

PhysXInfo.com: We bet you are already working on PhysX content for future games. Will they be able to surprise us?

David Schoemehl: Yes, we are constantly on the lookout for upcoming titles that can be enhanced with PhysX and APEX features. On each title we work with developers to do something new or better than in previous titles. In addition, we are seeing a growing number of developers independently experimenting with APEX tools. This is particularly true of the UE3 APEX integration.

Our job on the PhysX Content Team is to show developers and gamers what NVIDIA technologies can bring to games and we measure our success by the ease at which developers can add the features and the response we see from gamers when they play games with PhysX effects enabled. We look forward to continuously improving tools for developers and helping them bring more cutting edge PhysX enhanced games in the future.

Our big thanks to PhysX Content Team for the interview !

It is time to summarize what PhysX Technology has achieved in year 2011, recall the most memorable events and releases.

. GAMES

GPU physics acceleration still can not gain enough momentum – only two games with support for GPU PhysX effects were released this year, this is the lowest result since Ageia was aquired.

One may call this an agony, but NVIDIA has told us that it was “conscious decision” – time was taken to develop and improve underlaying technology (PhysX SDK, APEX, DCC tools), thus sacrificing ability to create content and  integrate it into many games.

It was promised that we will see “more GPU PhysX games next year than you did this year” and even “a lot more in 2013″.

Meanwhile, both GPU PhysX titles released this year were pretty interesting by themselves:

• Batman: Arkham City, one of the best games with hardware PhysX support.
• Alice: Madness Returns, which is a decent game too and is certanly worth more than two Darkest of Days.

PhysX SDK as physics engine is still widely adopted by developers – over 45 PC console and games were released this year, according to our database.

. PHYSX SDK & TOOLS

Looking on the SDK Development you can say where all resources were spent – brand new PhysX SDK 3.0, rewritten from scratch, optimized and enhanced with new features, was released in Q2 2011, followed by SDK 3.1 and SDK 3.2 Beta. 6-months release schedule was introduced and so far is impeccably fulfilled.

PhysX 3 is a strong technological foundation, that will ensure further expansion, evolution and success of PhysX as physics engine.

NVIDIA APEX 1.0, high-level scalable framework build on top of PhysX SDK, was also revealed for public along with UDK integration, however it can not boast with same release dynamics – new APEX 1.1, promised to be delivered this autumn is now postponed till 2012. APEX 1.2, fully based on PhysX SDK 3, is also supposed to be released next year.

DCC PhysX plug-ins went throught three versions – 2.6, 2.61 and 2.7 – but during this period several compatibility problems and significant delays of releases were faced.

. MISCELLANEOUS

MassFX – new physics simulation solution, using PhysX SDK engine, was introduced in Autodesk 3ds Max 2012, thus replacing Reactor system, which was based on Havok physics. Rigid Body simulation functionality of MassFX was pretty strong along with better performance, however many users were unhappy with reduced functionality set in comparison to Reactor.

According to yearly survey by Game Developer Magazine, PhysX SDK is preferred physics middleware solution for traditional (big-budget) developers.

PhysX Research Team has showcased some new interesting technologies and prototypes. Some of them will appear in future versions of PhysX engine.

After a long break, new 1.05 version of Hybrid PhysX mod was released to support recent drivers and GPU PhysX games in AMD + NVIDIA configurations.

. . .

Well, that is all for now.

Happy New Year to everybody !

Time to update PhysX performance metrics of NVIDIA GPUs with newest title with Hardware PhysX support – Batman: Arkham City.

In following article we’ve tried to gather all the benchmarks and tests, published on the web.

[25.11.2011] Batman Arkham City im Technik-Test: Grafikkarten-, DirectX-11- und Physx-Benchmarks by PCGamesHardware.de

German article with graphics benchmarks, overview of DX 11 and PhysX features, and a superficial PhysX tests.

[25.11.2011] Batman Arkham City GPU Test by GameGPU.ru

Includes PhysX benchmarks with over 20 GPUs tested, however, only on “High” PhysX settings without Hybrid PhysX or dedicated GPU tests.

[27.11.2011] Preview: Batman Arkham City – výkon grafik pod DX11/DX9 a PhysX by DDWorld.cz

Czech preview article with very basic PhysX benchmarking part (only one GPU tested).

[28.11.2011] Want to play Batman: Arkham City with PhysX enabled? Get ready for some abysmal framerates by DSOGaming.com

Despite of provoking title, measured performance is not that bad. Also, this is the first article with benchmarks of dedicated PhysX GPUs.

[30.11.2011] Waiting for the patch: Batman: Arkham Asylum in DX9 mode by 3DNews.ru

Russian article with some PhysX/DX11 effects overview and decent PhysX testing.

[02.12.2011] Technik-Check: Batman: Arkham City im Benchmark-Test by GameStar.de

Includes some benchmarks with different PhysX settings. Results are interesting – GPU PhysX effects on CPU (AMD card) are faster that GPU PhysX on middle-end NVIDIA cards (in this case, minimum fps would be more meaning than average).

[02.12.2011] Batman Arkham City, DirectX 9 e DirectX 11 a confronto by HardwareUpgrade.it

Technology overview and minor PhysX testing.

[05.12.2011] Batman: Arkham City Gameplay Performance and IQ Review by HardOCP

Once again, disputable benchmarking methodology from HardOCP – NVIDIA cards are tested with GPU PhysX effects enabled and compared to AMD cards with PhysX disabled. Thus, it is shown what GPU PhysX takes – performance, but it is not revealed what it brings – additional effects.

[17.12.2011] Batman: Arkham City Performance Review by Playwares.com

Detailed article from a Korean website, however, PhysX part is most interesting for us.

[17.12.2011] Batman: Arkham City Graphics Breakdown & Performance Guide by GeForce.com

Performance and features overview from NVIDIA itself. Graphs are interesting, for example this one shows ineffectiveness of dedicated PhysX card usage in pair with GTX 560 Ti GPU.

[10.01.2012] Batman: Arkham City — podívejte se na PhysX a DX11 v akci by PCTuning.cz

Good technical review (in Czech) with strong benchmarking part (includes CPU tests, for example). For some reason, PhysX effects were tested only on “Medium” settings though.

– We’ll update this post as more articles emerge –

Batman: Arkham City tests the patience of PC gamers with several release delays, but will try to wheedle them with DX 11 Graphics and PhysX Technology.

Update: GPU PhysX in Batman: Arkham City - review and comparison video.

Recent comparison trailer gave us a glimpse of extra physics effects, and now we want to provide you with some additional details on what to expect from GPU PhysX content. In addition, new comparison PhysX video was released as well.

As usually, it will be possible to adjust level of in-game physics via “Hardware Accelerated PhysX” option in game’s launcher. There will be three settings:

PhysX Off: all GPU accelerated effects are disabled, only standart CPU physics (like ragdolls) is used.

PhysX Normal: enables additional particles effects (debris, volumetric smoke and steam, etc) and destructible environments.

PhysX High: includes all effects enabled withing “Normal” settings as well as realtime cloth and clothing simulation.

PhysX particle effects, most widely used type of content in GPU PhysX titles, will find their place in new Batman game. Scattered across Arkham City, they will consist of:

• Interactive SPH-smoke from fire extinguishers and smoke pellets, dynamic steam and fog.
• Ice particles for Freeze Gun and Freeze Grenade.
• Interactive debris from destructible thrown objects, like stools and vases.
• Environmental specific particles: molten and electrical sparks, coal debris, chunks, etc.
• Extra particles jutting from destructible objects like breakable glass, tiles and walls.
• Forcefields for explosions that will push particles away.

Interactive smoke and debris from Batman’s explosive gel

In addition, PhysX cloth effects are emulating the behaviour of fabric and clothing to make Batman and his enemies more realistic, as well as lend realism to environments. They will include:

• Simulated clothing on characters: coats and hoodies for Penguin, Two Face, and Joker’s thugs; Bruce Wayne’s jacket, pants, and tie.
• Dynamic paper: eviction and office papers, posters, x-ray sheets, museum tickets, etc.
• Money littering the floor of the vault (Sewer level).
• Leaves on the ground.
• Various interactive cloth objects throughout the game: rugs, banners, curtains, flags, ropes, bunting.

Banknotes are simulated as invidial cloth pieces, affected by character and weapon movement

But beauty comes with a burden, performance wise – GPU PhysX effects, especially coupled with DX 11 features like tesselation or HBAO, can bring frame rate to its knees if your GPU is not fast enough.

Various tesselation settings

Following table (based on NVIDIA testing) provides recommended baseline settings for specific GPUs to ensure the comfortable combination of playability and features (average frame rate of 40-55 frames per second and minimum 35 fps).

Batman: Arkham City is set for launch on November 22 in US and November 25 in EU.

Don’t forget to visit PhysXInfo.com soon after game’s release for comparison PhysX video, screenshots and detailed overview.

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.

Metro: Last Light, sequel to Metro 2033 title, is aiming technology throne with DX 11, tesselation and support for GPU accelerated PhysX effects. PCGamesHardware.com had the chance to talk with Oles Shishkovtsov, Chief Technology Officer at 4A Games, about improvements that are planned for PC version of the game.

PC Games Hardware: You keep the support for GPU PhysX in Metro Last Light. If so can we expect some improvements or enhancements compared to Metro 2033 (e.g. soft bodies, debris, and destructible environments)? What graphics card do you recommend for maxed details in Full HD with Antialiasing? An upcoming Nvidia Kepler-based Geforce for example?

Oles Shishkovtsov: Yes, you can expect a lot of improvements, especially in destruction and debris. The upcoming Geforce cards will be fully supported.

PC Games Hardware: When benchmarking Metro 2033 we found out that the engine utilized more than four cores of multicore CPUs if we were using the advanced PhysX effects on CPU, so you are utilizing Nvidias PhysX SDK 3.x? Will all the advanced PhysX effects only be available in PC version?

Oles Shishkovtsov: That’s the common misconception that PhysX 2.X cannot be multithreaded. Actually it is internally designed to be multithreaded! The only thing – it takes some programmer time to enable that multi-threading (actually task generation), mostly to integrate with engine task-model and ensure proper load-balancing. So, 2033 used PhysX 2.8.3, and Last Light uses similar, a slightly modified version at the time of writing. And yes, advanced PhysX effects will be available only on PC.

Read the full interview

Sounds good.

However, we are hoping that this time Metro will be able to surprise us with more than two minor particle effects (as in Metro 2033 – while “debris, smoke and dust” were promised) and it won’t require “upcoming GeForce card” to run those GPU PhysX effects with playble framerate.

Almost four years has passed since NVIDIA aquired Ageia and presented their version of hardware accelerated PhysX Technology. However, anyone who is watching GPU PhysX progress closely can say, that so far it has not shown any significant advancement – but is the fight already lost or is it just taking time to harness up, but will ride fast?

We got a chance to chat with Tony Tamasi, Senior Vice President of Content & Technology in NVIDIA, Ashu Rege, Vice President of Content & Technology, and Rev Lebaredian, Director of Engineering, to clear up these questions, and recieve some insider information on future development plans for PhysX SDK and NVIDIA APEX toolset.

PhysXInfo.com: Over last years, amount of GPU PhysX games is actually decreasing. There were five games in 2009, three in 2010 and so far only one in 2011. How can you explain that?

Tony Tamasi: It was a choice on our part. We had a large amount of resources we could otherwise dedicate to content, but we needed to advance the core technology. We needed to get PhysX 3 done, and we needed to get APEX done to the degree where it is usable by game developers. We had to put a lot of resources there, which meant that some of those resources weren’t directly working on games.

But in the long term, game developers can actually use PhysX and APEX, and make use of the GPU without significant amounts of effort, so that a year or two years from now more games will come out using GPU physics.

Alice: Madness Returns - most recent GPU PhysX title

Rev Lebaredian: When we initially acquired Ageia, we made a big effort to move many games over to GPU PhysX. We learned a lot in that period of time: getting GPU physics into games, what are the problems, what works and what doesn’t. That gave us the opportunity to regroup, refocus, and figure out how to do it correctly.

We made a conscious decision. After we did a bunch of PhysX and APEX games in 2009 and early 2010, we said “Ok, we have learned enough, we need to sit down and focus on finishing APEX and changing it based on what we just learned, as well as PhysX 3”. Doing as many titles as we were doing before was just going to slow us down.

It made more sense to slow down the content pipeline but get the tools right, but that puts us in the position when once those are complete, it is actually less work for us to get PhysX in games.

This slowdown has not been because of any problems. It is something that we have decided to do.

PhysXInfo.com: So NVIDIA APEX is supposed to give developers the tools for easy creation on physical content in games, and you will receive GPU PhysX support as a byproduct. Is this idea working already?

Rev Lebaredian: It won’t be 100% free. Anytime you’re going to change the quality of something, you’re going to have the artists and level designers do a little bit of work to tweak it so it will look right.

Sure, let’s say if you have clothing you can just increase the number of vertices or increase the number of bodies for something with destruction, but most likely they going to want to tune it at different levels.

What we are trying to do with APEX is minimize that work. If you spend 10 hours putting together a set of assets for consoles, it shouldn’t take you another 10 hours to do the GPU stuff, maybe an additional half hour—depending on the developers and game in question obviously.

Tony Tamasi: And  I can actually tell you for sure, when we first started on the GPU PhysX effort, it often took more time to do the GPU physics work than core physics work, which is not the right balance. So we have to get the balance to make it incremental effort.

Ashu Rege: If you compare some games with APEX and GPU PhysX from one or two years ago, with some other games we are working on today, we have improved by 4-5 times in terms of less man-hours of work to get GPU PhysX done.

PhysXInfo.com: So how many GPU PhysX games are we going to see in upcoming years?

Rev Lebaredian: I think you’ll see more GPU PhysX games next year than you did this year, and I would expect to see a lot more in 2013. PhysX 3 and APEX are now just getting integrated–that’s why you see that kind of lag.

Tony Tamasi: We’ve also taken steps to integrate it [APEX/GPU PhysX] in major engines, like UE3—that enables a lot more developers to be able to use it out of the box now. When we did the GPU titles in 2009, essentially we have to do that integration each time. So there should be a large increase in GPU physics content just because it’s easier.

PhysXInfo.com: And for how long are you planning to further develop and use PhysX Technology?

Tony Tamasi: As long as we can see!

Ashu Rege: The interesting thing is that we haven’t even touched, frankly, the surface of the cool new things that can be done in many directions; things like heightfield fluid simulation, better cloth–I mean, there are so many different improvements, for both algorithms and technology as well as improvement for the tools so developers can integrate these features much faster.

So yes, we keep working.

PhysXInfo.com: Is the fact that GPU PhysX is exclusive to NVIDIA some kind of barrier for GPU PhysX adoption?

Rev Lebaredian: It is not a secret that most of game developers are concerned about consoles. PC for them is a smaller SKU usually, so PhysX not running on competitor GPUs  does not really matter that much to them.

Tony Tamasi: For every title we have worked on; for every one that I’m aware, that was never a reason for someone to use or not to use GPU PhysX.

PhysXInfo.com: Do you have any plans to port GPU PhysX to DX11 (Direct Compute) or OpenCL?

Rev Lebaredian: No plans to do it. Maybe if there will be a good reason for that in the future, but there is no current plan.

PhysXInfo.com: So developers are not asking you to port GPU PhysX to OpenCL?

Tony Tamasi: Nope.

Rev Lebaredian: No.

PhysXInfo.com: Are GPU PhysX effects going to be friendlier to multi-core CPUs in the future?

Tony Tamasi: You can use multi-core CPUs in PhysX 2.8, but it requires a lot of extra work to do that.  In PhysX 3 most solvers are parallelized across as many threads as are available.

Rev Lebaredian: It is usually not possible to get linear scaling with increasing numbers of CPU cores automatically. It is not reasonable to expect that if you’ll throw 8 cores at it, it will be 8 times faster.  However, we’ve done a lot of work in PhysX 3 to maximize usage of multiple CPU cores whenever possible.

PhysXInfo.com: What do you think about Hybrid PhysX? Isn’t it for good?

Rev Lebaredian: Good at what cost?

Supporting it would be a huge amount of QA for us, and it would be weird too – if we’ll find a bug in AMD’s drivers, what will we do?

Ashu Rege: For the foreseeable future we will not supporting it officially. If it works- it works, if some guys can figure out how to make it work – great for them.

After discussion of common topics, we have moved to more specific questions regarding PhysX SDK and NVIDIA APEX toolset.

PhysXInfo.com: New PhysX SDK 3. Has it already equals the hopes or was it waste of time, which has created more problems that it has solved?

Tony Tamasi: As far as I can tell, every developer we talked to is happy with it.

Rev Lebaredian: We have had developers demand to use it over 2.8, and that’s actually accelerated our plans for getting APEX working with it.

PhyXInfo.com: So developers now prefer PhysX 3 over 2.8?

Rev Lebaredian: Yes.

Ashu Rege: We build it to satisfy all their needs, so it would be really strange if they won’t use it. And we will be continuing to improve it to meet what developers are asking for.

PhysXInfo.com: Will PhysX SDK support next-generation consoles in the future?

Rev Lebaredian: Here is what we can say: we will always support all platforms that are relevant to our developers, so when the next generation consoles will become a reality, we will be on it.

PhysXInfo.com: Will PhysX SDK remain focused on games/game development area only?

Tony Tamasi: The focus is games. People can use it for visual effects or for manufacturing–that is awesome. And if we can do some incremental work to enable them, we’ll do that when we can, but the focus is games.

PhysXInfo.com: Are you thinking about enhancing PhysX/APEX product line with additional middleware packages, for animation or AI simulation, for example?

Ashu Rege: We work closely with our partners, with Natural Motion, with Autodesk, with game engine guys, but we are not interested in participating in that market; making money selling software. So it is not our goal to enter all of these areas.

PhysXInfo.com: What is the current development course for NVIDIA APEX?

Rev Lebaredian: We have decided to currently focus on two modules that have the highest priority for game developers – Clothing and Destruction.

EvE Online: APEX Clothing will make your hair long and silky

PhysXInfo.com: When we are going to see APEX with PhysX SDK 3 support? What are going to be the benefits, in comparison to current APEX with SDK 2.8?

Rev Lebaredian: Internally we already have version that works with PhysX 3. That’s one of the things on the roadmap. APEX 1.2 is going to be the first version of APEX we’ll release that will support PhysX 3.

Essentially, the benefits will be all the benefits that you get from PhysX 3 – better performance, and we’ll have all new features, new solvers, and all that kind of stuff.

PhysXInfo.com: Are you planning to port APEX to mobile platforms?

Rev Lebaredian: Yes.

Ashu Rege: Internally, we already have all of those working.

Tony Tamasi: And as soon as mobile devices will support CUDA, we’ll have GPU computation on mobile devices too.

PhysXInfo.com: APEX Destruction 1.1 will include fully functional GPU Rigid body solver (you were able to see in Art Gallery demo at GDC 11) – can you provide more details about it? Is this already finished technology or first iteration with many improvements to come?

Rev Lebaredian: We’ve done a lot of work on it since the Art Gallery demo last GDC.  It is more robust now, and behavior is better.  It is essentially the same, or maybe in some cases even better quality than the rigid body behavior in PhysX 2.8

Ashu Rege: We are at the point right now where we have three baseline things working–behavior, robustness and performance. We are continuing to enhance and improve it, especially on the performance front. It is using the exact same API [as CPU RB], except some pieces of the API are not implemented yet, so things like joints are not done.

Art Gallery demo was featuring GPU Rigid Body physics with up to 10 000 individual objects

PhysXInfo.com: What other features are planned for future versions of APEX Destruction?

Rev Lebaredian: There are lots of things we want to do with Destruction, real-time fracturing instead of pre-fracturing, all kinds of stuff. There are a lot of things in the plan and we have ideas on how to implement a lot of them, but what ends up driving features is the content. We work with game developers, see what it is they want, and we will change the priority based on demand.

PhysXInfo.com: New clothing solver was introduced in PhysX SDK 3.1. How does it compare to the previous one?

Tony Tamasi: It is faster and more stable, but it is not complete in terms of the feature set that is in PhysX 2.8, but we are adding those in the future.

PhysXInfo.com: Are you going to expand this new solver with all the missing functionality, or add additional specialized solvers in the future?

Rev Lebaredian: For collision geometry and similar features, we’ll expand the same solver. We haven’t decided yet, if we’ll want to introduce tearing for example.  That is a likely candidate for a different solver, because it never quite solved this problem correctly anyway. Sometimes it is better to have different solvers that solve different problems.

PhysXInfo.com: Will it support multi-core CPUs to the full extent?

Tony Tamasi: Yes

PhysXInfo.com: Are you planning to add this new clothing solver to 2.8 PhysX SDK?

Rev Lebaredian: The plan is if the developers are using PhysX 3.1, they can just use the new solver. If the developers are using 2.8 and they can’t switch to 3.1 for whatever reason, we can take the solver and make it build with APEX, so that they can continue to use PhysX 2.8 for all of their normal physics stuff and also use the 3.1 cloth solver with APEX Clothing.

PhysXInfo.com: Is authoring pipeline going to be different for new solver?

Rev Lebaredian: There are some modifications we’ve made. The parameter space is different and there are some new features, like tapered capsules for collision geometry–we obviously had to change DCC plug-in to support that.

PhysXInfo.com: When are we going to see new clothing solver in action?

Tony Tamasi: In games shipping next year.

As for us, all of the above sounds trustworthy enough and yet promising.

And what do you think ? Tell us in comments.

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.