[vtkusers] Re: VTK Textbook vs OpenGL Manual

[Scott J. Pearson]

I produce scientific visualization of fiber-spinning for polymers at Clemson
University. We sell an application for academic and industrial use towards
that end. We use both VTK and OpenGL in our interface.

You probably know that VTK is built upon OpenGL. I have read the OpenGL
manual (the "red book"), the VTK textbook, and the VTK user's guide and have
them within arm's reach at the moment. (I have not read the OpenGL reference
guide, the so-called "blue book.") VTK builds upon OpenGL concepts; VTK's
textbook explains enough of these concepts so that you can use it. However,
studying OpenGL will give you a better understanding of why VTK does certain
things and perhaps give you more ideas on how to exploit it. If you study
the OpenGL book closely, VTK concepts will seem easier. You should, however,
study pipelining from VTK as this concept is not present within OpenGL.

Most closely modeling what is going on in your graphics card, OpenGL
provides more flexibility and precision in use. It is also quicker. If there
is something that you want to design with a specific design, OpenGL is best.
However, the development process will be slower since you cannot rely on the
powerful VTK libraries.

VTK is great when it comes to displaying large amounts of data. For example,
I display data from mathematical finite element analyses. It is slow and
memory-intensive because it uses additional libraries.

Were I you and had time on my hands, I would spend the first half of the
semester studying OpenGL concepts. That gives you a solid foundation in 3-D
graphics. Aside from your course requirements, I wouldn't sweat the
nit-picky details of OpenGL calls. Then, I would read through the VTK
textbook. Some chapters will seem extremely easy because of your OpenGL
background.

If you want to start working with VTK right away, just read the VTK textbook
and you should have sufficient knowledge to begin coding. You will lack,
however, precise thinking about what is going on in the underlying
representation. (It's kind of like coding in C++ without knowing C.)

Sorry that this is so long. If you have further questions, feel free to ask.

Scott

---
Scott J. Pearson
Systems Programmer, Center for the Advanced Engineering of Fibers and Films
Clemson University     864.656.6389     scottjp at clemson.edu
10 Riggs Hall, Clemson, SC  29634
http://www.clemson.edu/caeff/