|By Mike Jacobs||
|July 31, 2005 07:15 PM EDT||
We Need More Power, Scotty!
Let's extend our particle system design to incorporate Shape3D particles. We still want to easily add the particle system to the Java3D scene, and reuse as much of what we've done up to this point. Recall that our particle systems use an emitter to control the initial position and velocity of the particles. The point and motion blurred particle systems deal with pixel size particles so we'll have to create a new type of particle system to handle Java3D shapes. So far, the particle systems have been Shape3D objects, so how can particles be any Shape3D object? Java3D supports the aggregation of shapes into a Group.
As you can see from Figure 6, the Shape3DParticle-System is a subclass of the Java3D Group class to allow shapes to be grouped together into a particle system. By implementing the IParticleSystem interface, the Shape3DParticleSystem can use the particle emitter unchanged. To help organize and control the shapes, the shape particle system maintains a scene graph segment for each shape in the particle system. Each shape has a scene graph segment consisting of a branch group to maintain membership in the particle system and a transform group to control the location, scale, and rotation of the shape.
Because particles are born and die during the particle system life cycle, shapes must be added and removed from the scene during the animation. Java3D limits the changes to the content of live scene graphs to branch groups. Provided the group (the particle system) has the ALLOW_CHILDREN_EXTEND and the ALLOW_CHILDREN_WRITE capabilities set and the branch group has the ALLOW_DETACH capability set, the branch group and its children can be added or removed from the scene. For our purposes, the only child of the branch group is a transform group. The transform group maintains the standard Java3D translation, scale, and rotation attributes of its child shape in a Transform3D object. With this structure in place, let's briefly review the Reeves life cycle for our new shape particle system.
Emit New Particles
From Figure 6 you can see that the shape particle system implements the IParticleLifeCycleListener interface. The particle emitter notifies listeners as particles evolve through their lifetime. This notification can be used to create additional effects such as spawning additional particle systems. Just before particles are emitted, the aboutToEmit() method is called on the listener, passing a list of particles to be emitted. The shape particle system reflects the initial particle position in the transform group and adds the branch group, transform group, and shape to the scene.
Bury the Dead Particles
When the particle emitter is ready to bury dead particles, it notifies listeners of their impending demise by calling the aboutToDie() method. The shape particle system takes the news pretty well by removing the branch group for the particles from the particle system, removing the shapes from the scene. To reduce object creation, the shape, transform group, and branch group are recycled for a future reincarnation.
Update the Surviving Particles
While particles are alive, the particle emitter applies the influences and the particles are moved, scaled, and rotated. After the particles have been updated by the particle emitter, it notifies the listeners by calling the updated() method. The shape particle system reflects the new particle position, scale, and rotation in the transform group. We discussed how linear acceleration and velocity of a particle can affect its new position, but how about rotation?
Slicker Than Euler
Realistic rotation of Shape3D particles with Euler angles can be mathematically intensive and computationally expensive. I'll try to keep the math to a minimum but if you are interested in the details, have a look at the references. If you have read much about three-dimensional graphics, you've probably already heard of Euler angles. An example of Euler angles is the yaw, pitch, and roll used to describe the orientation of an airplane. There are a few problems with using Euler angles that make them difficult to use for animation.
The order in which Euler angle rotations are applied can result in different orientations. While applying the rotations, a degree of freedom can be lost to something called a "gimbal lock". Over the course of multiple rotations, numeric corrections are often needed to keep the rotational animation looking good. Too make matters worse, it's computationally expensive to interpolate between orientations. Chris Hecker summed it up pretty well: "It's possible to prove that no three-scalar parameterization of 3D orientation exists that doesn't suck, for some suitably mathematically rigorous definition of suck." I did say that I would try to keep the math to a minimum. While Euler angles are easy to understand, we need something that overcomes the weaknesses of using Euler angles for rotational animation. This is where something called a quaternion can save the day (see the sidebar: Pop Quiz Hot Shot).
A quaternion is an extension to complex numbers consisting of a vector and a scalar. There's no use trying to picture a quaternion because it exists in four-dimensional space. In the spirit of keeping the math to a minimum, let's review the key features of quaternions. A unit length quaternion is perfect for representing a rotational orientation of an object. Java3D supports a unit quaternion with the Quat4f class. As the name implies, it consists of four floating-point numbers to make up the vector and scalar components of the quaternion. It's straightforward to convert Euler angles to a quaternion as shown in Figure 7.
Performing successive rotations with quaternions is as easy as multiplying them together. When compared to the traditional rotational matrix approach, quaternion multiplication (the details of which we won't cover here) and orientation interpolation is much more efficient, making it ideal for animating our rotating particle shapes. To animate the rotation, we need to specify the angular velocity in the vector portion of a quaternion. The angular velocity quaternion used to calculate the time differential of a quaternion is shown in Figure 7. The time differential can be used to interpolate quaternions, which helps us spin objects. That was probably the world's shortest description of quaternions, so be sure to review the references if you need more detail. Let's put this new knowledge to work in our shape particle system.
When shape particles are about to be emitted, the orientation is assigned through the use of Euler angles. The angular velocity is also assigned using the now familiar central value and variance approach discussed above. The orientation and angular velocity is converted into quaternions by the particle. When the particle is updated, the quaternion differential is calculated using the time interval of the particle system manager as described in Figure 7. Finally, the new orientation quaternion is set on the Transform3D of the shape along with the new position and scale and Java3D rotates the shape.
Vector3f translation = new Vector3f();
|mnjacobs 09/05/11 03:04:00 PM EDT|
The commercial version of this particle system is now available free including the source. Visit here.
|indie technologies 08/31/05 06:26:58 PM EDT|
http://www.indietechnologies.com now has this Java 3D technology available as a commercial product.
|indie technologies 08/06/05 07:05:33 PM EDT|
This technology is being commercialized for Java 3D game developers. Visit www.indietechnologies.com for more information.
|Java Developer's Journal 07/31/05 06:45:05 PM EDT|
Star Trek Technology for Java3D. The Star Trek universe has inspired many technology ideas but I'm disappointed I don't have a transporter yet. One Star Trek technology that has been available for sometime is the particle system. No, this is not an exotic propulsion system for your flying car. The particle system was invented to animate the Genesis effect in Star Trek II: The Wrath of Khan. While the Genesis device was used to transform a barren planet into one full of life, we can adopt this technology for more modest effects in Java3D.
|Mike Jacobs 07/11/05 09:04:30 AM EDT|
If you are looking for the source it is at the following link (my previous comment had a period at the end of the link).
|David Morris 07/01/05 09:25:29 AM EDT|
Mike, the stated link to the source code is invalid. Could you please update this link.
|Mike Jacobs 06/30/05 10:13:20 AM EDT|
The web editor decided to do things a bit different than the past. The first mention of the listings (Listing 1) is a link to all of the code. The link is http://res.sys-con.com/story/jun05/99792/source.html.
|Michael Yankowski 06/29/05 09:57:32 PM EDT|
I can't find any links to the source code.
|Mike Jacobs 06/16/05 11:32:10 AM EDT|
The source code is now current.
|Mike Jacobs 06/16/05 09:20:07 AM EDT|
It looks like the source for this article is slightly down level. JDJ is working on it.
SYS-CON Events announced today that MobiDev will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. MobiDev is a software company that develops and delivers turn-key mobile apps, websites, web services, and complex software systems for startups and enterprises. Since 2009 it has grown from a small group of passionate engineers and business managers to a full-scale mobile software company with over 200 develope...
May. 27, 2016 06:15 AM EDT Reads: 2,504
WebRTC is bringing significant change to the communications landscape that will bridge the worlds of web and telephony, making the Internet the new standard for communications. Cloud9 took the road less traveled and used WebRTC to create a downloadable enterprise-grade communications platform that is changing the communication dynamic in the financial sector. In his session at @ThingsExpo, Leo Papadopoulos, CTO of Cloud9, will discuss the importance of WebRTC and how it enables companies to fo...
May. 27, 2016 05:15 AM EDT Reads: 2,478
Companies can harness IoT and predictive analytics to sustain business continuity; predict and manage site performance during emergencies; minimize expensive reactive maintenance; and forecast equipment and maintenance budgets and expenditures. Providing cost-effective, uninterrupted service is challenging, particularly for organizations with geographically dispersed operations.
May. 27, 2016 05:00 AM EDT Reads: 1,893
SYS-CON Events announced today that MangoApps will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. MangoApps provides modern company intranets and team collaboration software, allowing workers to stay connected and productive from anywhere in the world and from any device. For more information, please visit https://www.mangoapps.com/.
May. 27, 2016 05:00 AM EDT Reads: 696
SYS-CON Events announced today TechTarget has been named “Media Sponsor” of SYS-CON's 18th International Cloud Expo, which will take place on June 7–9, 2016, at the Javits Center in New York City, NY, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. TechTarget is the Web’s leading destination for serious technology buyers researching and making enterprise technology decisions. Its extensive global networ...
May. 27, 2016 04:45 AM EDT Reads: 3,112
SYS-CON Events announced today that EastBanc Technologies will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. EastBanc Technologies has been working at the frontier of technology since 1999. Today, the firm provides full-lifecycle software development delivering flexible technology solutions that seamlessly integrate with existing systems – whether on premise or cloud. EastBanc Technologies partners with p...
May. 27, 2016 04:30 AM EDT Reads: 2,150
SYS-CON Events announced today that Tintri Inc., a leading producer of VM-aware storage (VAS) for virtualization and cloud environments, will exhibit at the 18th International CloudExpo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, New York, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
May. 27, 2016 04:15 AM EDT Reads: 2,267
SYS-CON Events announced today that BMC Software has been named "Siver Sponsor" of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2015 at the Javits Center in New York, New York. BMC is a global leader in innovative software solutions that help businesses transform into digital enterprises for the ultimate competitive advantage. BMC Digital Enterprise Management is a set of innovative IT solutions designed to make digital business fast, seamless, and optimized from mainframe to mo...
May. 27, 2016 01:45 AM EDT Reads: 2,091
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, wh...
May. 27, 2016 01:30 AM EDT Reads: 1,953
SYS-CON Events announced today that Alert Logic, Inc., the leading provider of Security-as-a-Service solutions for the cloud, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Alert Logic, Inc., provides Security-as-a-Service for on-premises, cloud, and hybrid infrastructures, delivering deep security insight and continuous protection for customers at a lower cost than traditional security solutions. Ful...
May. 27, 2016 12:45 AM EDT Reads: 2,717
The IoT is changing the way enterprises conduct business. In his session at @ThingsExpo, Eric Hoffman, Vice President at EastBanc Technologies, discuss how businesses can gain an edge over competitors by empowering consumers to take control through IoT. We'll cite examples such as a Washington, D.C.-based sports club that leveraged IoT and the cloud to develop a comprehensive booking system. He'll also highlight how IoT can revitalize and restore outdated business models, making them profitable...
May. 27, 2016 12:45 AM EDT Reads: 2,781
The essence of data analysis involves setting up data pipelines that consist of several operations that are chained together – starting from data collection, data quality checks, data integration, data analysis and data visualization (including the setting up of interaction paths in that visualization). In our opinion, the challenges stem from the technology diversity at each stage of the data pipeline as well as the lack of process around the analysis.
May. 27, 2016 12:15 AM EDT Reads: 1,361
SYS-CON Events announced today that Commvault, a global leader in enterprise data protection and information management, has been named “Bronze Sponsor” of SYS-CON's 18th International Cloud Expo, which will take place on June 7–9, 2016, at the Javits Center in New York City, NY, and the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Commvault is a leading provider of data protection and information management...
May. 27, 2016 12:00 AM EDT Reads: 3,053
Designing IoT applications is complex, but deploying them in a scalable fashion is even more complex. A scalable, API first IaaS cloud is a good start, but in order to understand the various components specific to deploying IoT applications, one needs to understand the architecture of these applications and figure out how to scale these components independently. In his session at @ThingsExpo, Nara Rajagopalan is CEO of Accelerite, will discuss the fundamental architecture of IoT applications, ...
May. 27, 2016 12:00 AM EDT Reads: 1,159
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York and Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty ...
May. 26, 2016 11:30 PM EDT Reads: 2,577
As cloud and storage projections continue to rise, the number of organizations moving to the cloud is escalating and it is clear cloud storage is here to stay. However, is it secure? Data is the lifeblood for government entities, countries, cloud service providers and enterprises alike and losing or exposing that data can have disastrous results. There are new concepts for data storage on the horizon that will deliver secure solutions for storing and moving sensitive data around the world. ...
May. 26, 2016 11:00 PM EDT Reads: 1,254
18th Cloud Expo, taking place June 7-9, 2016, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Meanwhile, 94% of enterprises are using some...
May. 26, 2016 10:45 PM EDT Reads: 3,116
SoftLayer operates a global cloud infrastructure platform built for Internet scale. With a global footprint of data centers and network points of presence, SoftLayer provides infrastructure as a service to leading-edge customers ranging from Web startups to global enterprises. SoftLayer's modular architecture, full-featured API, and sophisticated automation provide unparalleled performance and control. Its flexible unified platform seamlessly spans physical and virtual devices linked via a world...
May. 26, 2016 10:15 PM EDT Reads: 2,093
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, will provide an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life ...
May. 26, 2016 10:00 PM EDT Reads: 1,896
In his session at 18th Cloud Expo, Bruce Swann, Senior Product Marketing Manager at Adobe, will discuss how the Adobe Marketing Cloud can help marketers embrace opportunities for personalized, relevant and real-time customer engagement across offline (direct mail, point of sale, call center) and digital (email, website, SMS, mobile apps, social networks, connected objects). Bruce Swann has more than 15 years of experience working with digital marketing disciplines like web analytics, social med...
May. 26, 2016 09:00 PM EDT Reads: 1,269