3D Animation Workshop: Lesson 84: More on MetaStream
Lesson 84 - More on MetaStream- Part 3
The current version of MetaStream is simply a vehicle for examining textured models, and so no animation in MAX is exported in the .mts file. Along the same lines of thought, a MAX scene should be exported as a single object. This means that all of the separate mesh objects in the scene should be attached together (using the Editable Mesh Attach tool) to create one Editable Mesh object.
If you're going to be able to zoom in close to examine objects, you obviously need high-resolution texture maps as much as you need high-resolution geometry. I've really been impressed with how sharp the textured surfaces are on the products MetaStream.com modeled for the Sony Vaio Direct and Sony Xtras Direct sites. But this means large file sizes for the image maps, and therefore longer download times.
Getting MetaStream files into a Web page involves the kind of confusing browser compatibility issues that dog all aspects of Web development. The MetaStream plug-in is available as an ActiveX control or as a set of Java classes. Only Microsoft Internet Explorer (and then only for Windows) supports ActiveX controls. Thus the user has only one of the two types of plug-ins with respect to a given browser. I tested this by first installing the plug-in while in Microsoft Internet Explorer. I then tried to open a page with MetaStream content while using Netscape. Netscape informed me that I needed to install a plug-in, and when I did, the procedure was a little different, requiring me override the default security limit for the use of Java classes.
To deal with the dual plug-in issue, the developer must nest two different tags in the HTML page. The OBJECT tag is used for the ActiveX (Microsoft) version. But within the OBJECT tag, you can include an EMBED tag that calls the non-ActiveX version. The client's browser will pick the one it can use. In either case, the tagged information indicates the size of the 3D viewing window and the name of the .mts file to load. After that, you can choose to include any or all of a wide range of parameter values. This is a very interesting aspect of MetaStream because it provides a great deal of flexibility to Web developers who are implementing 3D content that they did not create themselves.
For example, you can specify a background color or background image. You can set the number of anti-aliasing passes to reduce pixel jaggedness, although any improved image quality necessarily comes at a price in interactive speed. By default, a user can rotate the model in any direction, and can pan or zoom, but you can choose to constrain any of these parameters. You can even specify a link to an URL that will load when the user double-clicks the object.
Even this early stage in the arrival of 3D on the Internet, a couple of major threads seem to be emerging. One, building from the success of games and other interactive media, sees 3D as a vehicle for entertainment, education and advertising. Another, more limited but just as technically demanding, seeks to make photorealistic 3D models of real-world objects for close examination by customers in an e-commerce setting. The first direction is exciting, but still vague. The second is at least clear and direct, and is the thread that MetaCreations and MetaStream.com are following. As I look at the MetaStream work on the Sony sites, I feel that we are very close to something real. Right now, the rendering panels are a bit too small for meaningful examination of products. But over the next year or so, with massive increases in user processing power and the standard installation of 3D hardware on all new workstations, you'll be seeing these same consumer products full-screen and life-size. And when you do, the 3D Virtual Store will no longer be a cool attraction or technological gimmick. It will be as mainstream as the stack of catalogs that clogs your mailbox every Christmas.
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Created: Jan. 17, 2000
Revised: Jan. 17, 2000