September 23, 2005 Developer View: Bandai Networks	[Back]
Bandai Networks, a Japanese developer and supplier of mobile phone entertainment content, share some of the steps their development team went through to convert their Japanese Java games developed for the DoJa Platform ("DoJa" for DoCoMo Java) predominantly in Mascot Capsule v3 into MIDP 2.0 and JSR 184 based games for Sony Ericsson phones.

The questions below have been answered by Motomu Watanabe, Manager of Business Development in Europe and US at Bandai Networks.

Full company name
Bandai Networks

Year founded
In 2000, as a subsidiary of Bandai Co. Ltd.

Company description
Bandai Networks have been developing many types of Java applications for mobile, including games, e-mail clients and standby Java applications for more than four years. Java services for mobile started in Japan in January 2001 with NTT DoCoMo as the first mobile Java service in the world. Bandai Networks have consistently supplied NTT DoCoMo with applications, gaining extensive experience in mobile Java technologies in the process.

In order to provide mobile phone users with entertainment content, Bandai Networks have built on our parent company's strength in character merchandising. Bandai Networks have developed a mobile content service that is "easy and fun for everyone". Not being limited to the medium of mobile content, Bandai Networks have also introduced cutting-edge technology to expand the potential of mobile devices, and search for new ways to provide entertainment through internet e-commerce.

Bandai Network's experiences of mobile Java 3D development

Why did Bandai Networks start with mobile Java 3D development?
Bandai Networks believe that 3D games make the mobile phone content industry more attractive to consumers, operators and developers. We put a strong emphasis on 3D as we have developed a 3D graphics engine and a number of 3D titles for mobile phones. We offer our 3D games to operators around the world. Bandai were in fact the first company to provide 3D games for the European mobile phone market through Vodafone Live!

What appealed to Bandai Networks about Sony Ericsson mobile phones?
Sony Ericsson mobile phones have a steady 3D platform with great performance. It's easy to adapt our available 3D games in Japan to Sony Ericsson's GSM/UMTS phones which means that we can quickly bring the latest 3D games to consumers around the world. This is good news for users, operators, Bandai and Sony Ericsson.

Why did Bandai Networks adapt existing Mascot Capsule v3 games to JSR 184?
Although Sony Ericsson phones support both Mascot Capsule v3 and JSR 184, the Mascot Capsule implementation is different between the Japanese platform and the GSM/UMTS phones. At Bandai Networks, we wanted to re-use our successful Japanese Mascot Capsule v3 games to address increased demand from European operators for 3D games, but in order to make our 3D games compatible with as many handsets as possible on the global market, we decided to go with the standard and port our existing games to JSR 184.

What development steps did you take to convert your DoJa Platform games to Mobile Java 3D?
To convert an existing Japanese Java game to a Mobile Java 3D game for Sony Ericsson GSM/UMTS phones, Bandai Networks identified three development steps.

1. Recreate 3D graphic data in JSR 184 format
   The original data was imported to Lightwave in order to create 3D graphic data in the JSR 184 format. Only "Model data" was used as is, but "Animation" and "light source" needed to be created from scratch. As the JSR 184 format is completely different to Mascot Capsule v3, Bandai Networks found this work to be really time consuming. However, a JSR 184 plug-in converter for Lightwave is now available so this stage is no longer a problem for Bandai.
2. Modify the source code from the DoJa Platform and Mascot Capsule v3 API to MIDP 2.0 and JSR 184
   To achieve the modification of the Japanese DoJa and Mascot Capsule v3 source code into MIDP 2.0 and JSR 184, Bandai needed to divide the source code into two parts: the 3D graphics part and the 2D graphics part. The 3D graphics part needed to be reprogrammed from scratch as the Mascot Capsule v3 API is completely different to JSR 184. But the modification of the 2D part was not difficult for Bandai as we simply changed the process into a method. The source code for calling a method is the same for all Java platforms, but processes within a method are customized for each target platform. Bandai Networks have a great deal of experience in the MIDP area and we have many libraries for porting our games from the Japanese DoJa platform to Java ME MIDP 2.0, making the porting easy and fast.
3. Install modified source code to target handset and debug it
   This stage was a phase of trial and error for Bandai. We transferred jad and jar files to the target handset and then debugged the files on the handset. We found using a Bluetooth or IrDA connection extremely valuable as there is no GSM network in Japan. This allowed us to develop 3D games in our home country of Japan.

What challenges did you face adapting your Japanese 3D games?
Bandai Networks faced two big challenges the first time that we developed 3D games for mobile phones supporting JSR 184.

1. The challenge was to obtain a converter tool for JSR 184. There was no converter tool when we started developing, so we had to wait for it from HI Corp who supported us throughout the 3D game development. However, we did not receive the final version until much later and had to debug the converter in parallel to developing 3D games.
2. The other challenge was to make some polygons appear simultaneously. The normal behavior is that if polygons are drawn at the same time, they never appear on the display. Bandai tried to change camera angles and the way that some polygons are drawn to have them appear at the same time. Finally we found a solution by setting center points of the polygons within the Java ME drawing area.

What's your view on the future of mobile Java 3D?
3D technology is very important for Bandai Networks as it helps expand our mobile business. We are now using 3D graphics in a new way for mobile phone screensavers and wallpapers, both in Japan and Europe, even allowing the user to choose the character's pose. Bandai Networks will continue to develop non-gaming 3D applications, as well as 3D games from Japan, and bring them to mobile users around the world.

If you could give one piece of advice to other mobile developers porting games from one platform to another, what would it be?
Have as many libraries as possible - this makes porting easy and fast. Our way of porting games is a source code for calling method and is the same for all Java platforms. But processes in the method need to be customized for each platform, so that's why having access to as many libraries as possible is a huge asset.

What in your view is the next big thing in mobile applications development?
A flat-rate for data traffic and 3D acceleration for mobile phones.

More information:

• Visit Bandai Network's web site>>
• Read Bandai's press release HI and Bandai Networks supply new 3D wireless games for Vodafone Live!>>