We saw that module inputs and outputs are tersely named and briefly described. But some rather complex and wonderful operations go on inside many modules: I've alluded to some of these operations above. To get more detailed information on a module and its inputs and outputs, we can use the online contextual Help functions in DX.

Bring the VPE to the top. Be sure you can see the Isosurface module in your net. Pull down the Help menu on the top right of the VPE and choose the Context-Sensitive Help function. Your cursor becomes a question mark. Hover it over the Isosurface module and click once. The contextual help on Isosurface should pop open. If you missed and clicked on some other part of the VPE, you got a different contextual help screen. Close it and try again so we can talk about the Isosurface Help.

Virtually all the modules have a similar look to their Help page, though some are shorter and some are far longer. Here you see the module and category name and a brief description of what the module does. The text under Syntax (green on my screen) is an example of the DX Script Language. It shows how you would call the Isosurface routine within a script.

We won't talk about scripting in detail in this workshop, but you might want to note for future reference that you can create textual scripts that duplicate most of the functionality of a network program. This could be useful for batch processing or other needs. But you do have to type text, catch spelling errors, carry the whole program logic in your head, and so on, just like any other text-based language.

The next block shows the same information on inputs and outputs as we found in the CDB. But after that, the gory details begin for each and every input and output, and other technical details you'll someday be glad to know. At the end of this descriptive section, there is generally a paragraph that describes which components are affected by the particular module you are studying. Isosurface is one of the more dramatic in that it modifies virtually every component of its input and produces quite a different object as output. Take a look at the Help page for AutoColor to see an example of a module that does far less internal restructuring of its input.

At the end of the Help page are listed sample programs (from dxsamples-x.x) that illustrate various uses of the module you are reading about. This is a good way to review how the module is used in context. Other related modules are listed under See Also, then finally there's a hyperlink to the Next Topic (generally completely unrelated).

This same information page is what you will find in the html documentation under User's Reference, Functional Modules. The html is more current so you may want to check both versions if you are having problems that need clarification.

Unfortunately, many of the other items on the Help menu are only partially up-to-date. This Help system was created many years ago before a lot of more modern standards such as Adobe's PDF format and html had been invented. At the time, there was no good way to put illustrations and diagrams into the online Help, so you see constant referrals to the "printed manuals" for these. While most of these illustrations do appear in the html documentation, a casual inspection shows that the reference numbers still listed in the old online Help don't appear to match the numbering of the illustrations in the html. So, I'm afraid you are somewhat on your own if you use the other Help features. You are much better off to spend time reading the html documentation and browsing the PDF documentation I mentioned in the introduction. In the html, some portions of the documentation, especially involving typesetting of subscripts, multiline brackets, etc., do not translate correctly, resulting in gobbledygook. In the PDF documents, this all appears correctly.

Using the Context-Sensitive Help system within the VPE, research the following modules: Transformation: Compute Debugging: Print Flow Control: Switch Interactor: Selector You don't need to memorize everything about the modules, just get a handle on what they do. If you like, play with the Samples referenced by each module's Help to see them used in context. To access their Help, you may either place a copy of the module on the net (no need to hook it up), or you can click the Question Mark cursor directly on the Tools section to bring up a help page table of contents to all Tools in that category.