What are they and are they the same thing?
We need a couple of definitions.
A Web Application is a website that provides some sort of substantive functionality other than simply filtering and presenting information. Evernote is a fantastic web app that stores your notes on a server, and allows you to create, group, and annotate your notes. Some folks say that a web app makes it clear that there is an application at the other end of your browser, and not just a bunch of static data. This is admittedly a pretty soft definition, but it’s reasonable. Another way to look at it is that a web app provides what would otherwise be a desktop application, but makes it accessible from a server so that users do not have to install and maintain an application.
Web 2.0 refers to web development frameworks and tools that can be used to create highly responsive websites and web applications. AJAX does this, and the conical example people give is Google Maps. AJAX allows data to be retrieved asynchronously while a prior page is being displayed and manipulated by a user, and minimizes the amount of a web page that must be replaced with the next refresh.
A somewhat newer approach is embodied in Adobe Flex and Microsoft Silverlight technologies; in these cases, a web app is sped up by running more of the application’s logic inside a browser plugin (Adobe Flash or Microsoft Silverlight), rather than making the client machine (which runs the user’s browser) continuously talk to the web server. The overall challenge is to make web pages highly dynamic (meaning the data comes from a database and is not hard-coded in the web page) while giving the user response times that approach those of a desktop application running on a dedicated or near-dedicated machine. While this is intractable at this point, it’s a good thing to hold up as a goal.
The Semantic Web.
This term refers to a still emerging body of software tools whose overall goal is to automate the collection and integration of information gleaned from websites. The idea is to free the Google/Yahoo user from painfully interactive, highly repetitive keyword searches where we continue to hone our queries until we seem to be finding the right stuff.
Semantic Web technology includes namespaces, which try to put more smarts in websites by having data tagged with widely shared, standardized sets of tags. And things like XML Schema and XQuery can be employed to leverage namespace technology to support high-volume, set-oriented queries of data stored on web servers.
First, we create a polygon cube.
Now we choose Proxy -> Subdiv Proxy from the main menu, and we get this:
Now we select Proxy -> Crease Tool from the main menu. This will put us in edge mode.
We select a bottom edge and get this:
Then we push down the middle mouse button and pull to the right. We get this:
Look carefully – you can see that we sharpened the model along that bottom edge of the cube.
If we select all four top edges and then select the Crease Tool and pull to the right, we get:
There… We did a lot of creasing…]]>
Curved line vector modeling for 3D graphics.
In five recent postings, (1, 2, 3, 4, 5), we looked at the simple, powerful mathematical techniques that underly the specification of curved lines in 3D graphics and how they are used to create 3D models.
Straight line vector modeling for 3D graphics.
In the last three postings (6, 7, 8), we turned to straight lines, and how 3D models can be built entirely out of 2D straight lines, using polygons. We also looked at the minimal information a graphics or animation application must manage in order to unambiguously represent a 3D object created with straight line geometry – and we saw that it isn’t very complicated at all.
We left off with a Moai that we were modeling using polygons and a handful of very simple Autodesk Maya tools.
Using edge loops to add geometric detail.
Consider the image below. It shows the Moai statue that we began to build in the last posting of this blog. We have added more edge loops to give us the detail we need for pulling out the features of our Moai from the cylinder with which we began.
We have selected vertices on these edge loops and pulled on them to create the nose and the mouth of our Moai.
Pulling edges to make the facial features.
Consider the image below:
We have continued to mold the facial features out by selecting edges on the object and pulling them out. This way, we turn the very narrow features we created by pulling on vertices into wider features that begin to resemble a face.
There is a general concept here: manipulating vertices, edges, and faces.
With polygon modeling, we create an object out of a mesh of polygons. To craft the model, we can select vertices (where edges of polygons meet), edges (the lines that form polygons), and faces (the surfaces of the polygons themselves) and push/pull them to craft out model from a geometric primitive – in this case, a cylinder that has been sliced in half.
More next time. ]]>