The support of online video streaming

Some of the X3D viewers support video streaming (and some even 3D streaming, for things such as augmented reality).

Which one is the standard and will target a lot of users

X3D is a standardized format, such as JPEG with multiple companies being able to manipulate such data and is even officially recommended by HTML5 specs whereas Unity ties you to a single company. Even if most X3D viewers are plugin-based like Flash, there exists also native implementations such as X3DOM to display/interact with X3D files for any browser that supports WebGL.

Connection to DB, SOA and web services

I would usually recommend using a webservice for interfacing with a DB, and yes, X3D can interact with webservices (XML, JSON). There is even a standard binary format that is fast to transfer and parse large contents faster.

Supporting of multi player

Some X3D-supporting providers offer a multiusers service, such as Bitmanagement s BS Collaborate server, but I ve seen people using Darkstar/RedDwarf to make multiusers 3D environments as well.

the support of online video streaming

Unity 3D does not support video streaming, unless done through textures, which will give you a really slow frame rate.

I don t know for sure about X3D, but I would doubt it was really made for such tasks.

Silver light has good video support, it should be easy to stream with.

HTML only supports streaming video if using HTML 5, for which it gives the best user experience when user s browser supports it.

Flash is the de-facto for video streaming. It is extensively widespread. They use it for YouTube for example.

the budget of using each one

The cheapest of them all is HTML, it is free. Then you can theoretically set up something for free in flash using Flex SDK and server streaming technology such as Red5 (both open source and free). After that, I believe that all others would probably be on par cost wise, Unity3D coming in as the cheapest of the paid alternatives.

Learning Time will be needed to learn the technology

Listed in order of fastest one to learn to slowest (assuming no prior experience in any):

1. HTML
2. Flash/Silverlight
3. Unity3D
4. X3D

Which one is the standard and will target a lot of users

Flash is the most widespread. Its only competitor would be HTML 5, as new browsers tend to support it and its the only possible option on iOS. On the other hand, if 3D is what you want, then Unity3D is the standard for now, might be followed by HTML 5 in the future.

The support if I found any problem

Well, Unity3D would offer you good paid support, flash and silver light also (but only when you pay for streaming server licenses). HTML, X3D will not give you any support, but you can find a lot of information on the internet. There is also extensive information about Flash and Silverlight on the internet, but mostly Flash.

Bugs and security issues

All are pretty secure, I m just not sure about X3D, but all others are comparable in term of security or bug issues.

connection to DB, SOA and web services

Easy to do with HTML, Flash and Silverlight. Harder with Unity3D, and hardest with X3D.

supporting of multi player

Multi-player what? If you are making a game, then clearly I would say your real options are Unity3D if the game is to be in 3D, Flash if it is to be done in 2D. Check out SmartFoxServer for easy multiplayer server.

My 2 cents:

• the support of online video streaming: Some X3D players do support it. Unity does in some ways : http://unity3d.com/unity/features/audio-and-video

• the budget of using each one: X3D and Unity3d are free. You can pay for Unity licenses for extra features and platforms like iOS and Android. If you need to write plugins for Unity, you ll need the $1500 license. There are no costs for distribution of Unity products.

• Learning Time will be needed to learn the technology: Both X3D and Unity3d have active communities and many online resources and offline books. Unfortunately for X3D, the best content creation tool (Vivaty Studio) is no longer supported officially, but X3D is supported in Maya, Max, Blender, and many other 3D programs. Unity s online docs are excellent and the answers.unity3d.com forum (and other forums) are free and fast.

• Which one is the standard and will target a lot of users: Standard Well, HTML is the broadest standard. X3D (if including VRML) is the oldest most widely used 3D standard. HTML you have. HTML5 is coming, real soon now (I m already turning blue). If you mean most readily available the HTML is #1, Flash is #2 (as everyone has a browser, and most computers come with Flash installed already). Flash needs to be installed. Unity needs to be installed too, but it s at least as fast and easy to install as Flash, and it s gotten millions of downloads, so it s getting pretty pervasive. X3D requires a plugin (this should change sometime real soon now with x3dom on HTML5), but the many X3D players are all a little different from each other.

• The support if I found any problem: All have much online community support. X3D has a spec committee but that s not really support per se, you d have to contact the X3D plugin provider (Bitmanagement, Cortona, Octaga, Exit Reality, Fraunhoffer, etc.) Unity has great online community forums, you can pay for premium support, but I d only do that if I needed a serious bug or feature that has no work-around.

• Bugs and security issues: X3D s bugs depend on which player you use. Unity has bugs, but the product is pretty solid (I ve only crashed it once, and I use is all day, every day, for over a year). Both have a mind toward security, but neither of these are totally secure, especially since you can write scripts that are inherently not secure. So you have a hand in how secure YOUR content will be. Some X3D players support encryption. Unity products are compiled.

• connection to DB, SOA and web services: You can use something like AJAX or JSON or whatever in all these platforms, no? So if it s by web service, sure. If by direct local access, I know Unity can do that. Both Unity and Flash require cross-server xml files on the server to allow access cross-domain (in the web player for Unity anyway).

• supporting of multi player: Unity has excellent multi player networking components. X3D (spec) supports it too, but it really depends on which X3D player you go with as to how well it actually works. Worst case, you can use AJAX or JSON or whatever to roll your own.

Which you choose depends mostly on what you want to do with it. Flash is generally the best route right now, unless it s all about 3D, then I d try Unity. But a year from now, HTML5 alternatives will begin to take over. Flash DOES support 3D, there are different ways it can be done. Vivaty had a full-featured X3D player written in Flash, so it can be done. There are several good 3rd party 3d plugins for Flash.

I totally agree with wildpeaks : )

Connection to DB, SOA and web services: easy to do with HTML, Flash and Silverlight. Harder with Unity3D, and hardest with X3D.

Reply: I think X3D is not hardest.

X3D(X3DOM) can interact with webservices (XML) as very easy in this example/tutorial

Flash supports hardware accelerated 3d, and comes out of the box with 3d support. In addition, there is the papervision library for more advanced 3d. Unity3d is also supported as a flash library.

I would consider Flex as a real alternative to Flash. It has the same actionscript language, but uses a tag based syntax called MXML, similar to silverlight. Database remoting is extremely simple. You can access your .Net/Java/Php objects directly on the front end without having to deal with serialisation issues. All of the Flash libraries are accessible.

There is also the X3D player from instantreality.org, supporting video streaming & decoding, XMLHttp request via scripting and its free for non commercial usage.

Flash 3D isn t good 3D for any application of real-time 3D. It is 2.5D with some tricks.

X3D is easy to learn for simple things and harder as complexity goes up. It does have the advantage of being VRML with pointy brackets so the free content, examples and toolkits are easily found. I did comparison tests of the various players. BS Contact is the best for the ability to handle the most complex content with the fastest frame rate and rich color palette. Network support is still non-standard although XMLHTTP and database connections are easy to bolt on. As others have said, Instant Reality is coming on fast and supported by people with a deep understanding of the past implementations and future requirements.

The decision comes down to the project type. A simple comparison rating such as you are is misleading at best but thanks for giving it a shot. I ve used VRML through all of its incarnations and now X3D for world building and now as a source for 3D models in video work in combination with Sony Vegas. For cost-benefit without the need to use very expensive modeling toolkits, it is the best of all the choices.