In this paper we present a guide for writing use cases for the Declarative 3D for the Web Architecture, use cases where embedding 3D data in HTML using declarative approach provides signi cant bene t. We list components of a use case which we believe are essential when writing use cases and then we walk through a simple use case example. We believe that thanks to properly described use cases, it will be much easier to deduce di erent required dimensions for the Dec3D speci cation.
The Declarative 3D for the Web Architecture W3C Community Group1 has been formed to explore and suggest options for new declarative ways of incorporating 3D graphics directly into HTML to enable its use on any Web page. The core mission of the Declarative 3D Community Group is to determine the requirements, options, and use cases for the declarative integration of interactive 3D graphics capabilities into the Web technology stack which will provide a foundation for future standardization.
Therefore, in this paper we aim to create a guide for writing
e ective use cases for the Declarative 3D [
Dec3D2012 workshop at WWW2012, Lyon, France 2.
There are several components of a use case which we believe
are essential when writing use cases for the Declarative 3D.
In the following we will describe these components [
Paul - math teacher running MathBlog - a blog dedicated to promoting the beauty of Mathematics; knows basic HTML; Peter - scientist who writes web-based articles on his website BioScienceSite, where he discusses proteins, genes, etc; knows HTML and is experienced in using 3D modeling software (Blender, 3DS Max); Patrick - professional web developer working for DevMasters; he has good knowledge of HTML, JavaScript, CSS; currently working on VirtualMuseum and CarCon gurator projects; Penny - museum curator, working with Patrick on a virtual museum exhibition called VirtualMuseum; she has good knowledge of 3D scanning technologies; Ula and Ulrich are typical Internet users; they have good understanding of hypertext-based Web interaction; Ula is an accountant and has little experience with 3D graphics; Ulrich is a math and biology student, who occasionally plays 3D games.
We believe that such short user stories can help to set the stage for use cases by building up the context.
Description: Short and simple (plain English) description
of a use case. The purpose is to e ectively transfer
knowledge from the domain expert to the software developer.
Starting code: Starting sudo-HTML code
Complete code: Sudo-HTML, after declaring 3D scene.
Using the web site: Description of end-user interaction
with a web site (support for Web and 3D tasks [
Screenshot/Demo: Depiction of expected design,
screenshot, or a link to a working demo (created in e.g. [
In the following we describe a very simple use case for Declarative 3D. We hope that such description can be leveraged to create more complex use cases in future.
Title: MathBlog - Adding basic 3D geometry to a post Description: Paul, who maintains a MathBlog, wishes to enrich his new post about geometric gures with 3D representations of those gures. For this purpose, he chooses to use shape nodes and declare them in the HTML. Starting code: Paul's starting HTML (before declaring 3D) is presented on the Listing 1. 1 <html> 2 <head>< t i t l e>Pauls Blog</ t i t l e></ head> 3 <body> 4 . . . 5 <d i v i d="Post2011 07 21 "> 6 <h2>Geometric F i g u r e s</h2> 7 <p> 8 9 10 11 12 . . . 13 </ d i v> 14 </body> 15 </ html>
The cube i s a 3D s o l i d o b j e c t bounded by s i x s q u a r e f a c e s , f a c e t s or s i d e s , with t h r e e meeting at each v e r t e x . </p>
Complete code: Paul's HTML, after declaring 3D scene, is presented on the Listing 2. 1 <html> 2 <head>< t i t l e>Paul ' s Blog</ t i t l e></ head> 3 <body> 4 . . . 5 <d i v i d="Post2011 07 21 "> 6 <h2>Geometric F i g u r e s</h2> 7 <p> 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 . . . 24 </ d i v> 25 </body> 26 </ html>
The cube i s a 3D s o l i d o b j e c t bounded by s i x s q u a r e f a c e s , f a c e t s or s i d e s , with t h r e e meeting at each v e r t e x . </p> <dec3d width="400 px " h e i g h t="400 px "> <s c e n e> <v i e w p o i n t p o s i t i o n="0 0 10 "/> <shape> <appearance> <m a t e r i a l d i f f u s e C o l o r="0 0 1 "/> </ appearance> <box DEF="box " s i z e="1 1 1 "/> </ shape> </ s c e n e> </ dec3d>
Using the web site: Ulrich can see the post with the static 3D box geometry. No interaction is possible.
Derived requirements: This use case leads to the following requirements: Requirement SR01: Simple D3D Syntax. 4.
CONCLUSIONS AND FUTURE WORK In this paper we presented a guide for writing use cases for the Declarative 3D for the Web, use cases where embedding 3D data in HTML using declarative approach provides signi cant bene t. We believe that thanks to properly described use cases, it will be much easier to deduce di erent required dimensions for the Dec3D speci cation. Having a use case catalog, such as at Declarative 3D Community Group Wiki is bene cial, however, a certain problem remain: the size and variety of the use case space and its lack of graphical representations limit its usefulness in the use case discovery, exploration and understanding process. In order to address this issue we propose to employ interactive, visual aids to assist users, allowing nding relevant use cases both e ciently and e ectively. As the human brain enables us to see, explore, and understand large amounts of visual information at once, we want to focus on the creation of an interactive (possibly 3D) use case diagram and elements to visualise information about di erent characteristics of use cases. Data visualisation techniques (e.g., graphs, trees, etc.) in tandem with graphical capabilities of modern browsers, can be used to present use cases in innovative ways. We believe that, as a result, users will be able to easily identify relevant use cases, unearth previously unseen correlations between them, or learn about related requirements. * Visit http://declarative3d.org and contribute with your use cases for the Declarative 3D for the Web. ** This work has been supported by SFI under Grant No. SFI/08/CE/I1380 (Lion II) and by EI under Grant No. PC/2008/353 (Copernicus).