From: mott@clamato.asd.sgi.com (David Mott)
Newsgroups: comp.sys.sgi
Subject: Re: FAQ on Inventor
Date: 2 Oct 1992 17:48:07 GMT
Organization: Silicon Graphics, Inc., Mountain View, CA
Distribution: world
NNTP-Posting-Host: clamato.asd.sgi.com

In article <miguel.717758477@lilly> miguel@lilly.gris.informatik.uni-tuebingen.de (Miguel Encarnacao) writes:
>
>Is there any FAQ available about Inventor? If so, where?
>

The FAQ on Inventor is short enough at present to simply post right here.
It will grow as more questions are asked frequently.

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DATE
    August 27, 1992

TITLE
    Frequently Asked Questions On IRIS Inventor

KEYWORDS
    3-D, 3-D graphics, C++, GL, computer graphics, file format,
    interaction, objects, picking, object-oriented

QUESTIONS TABLE OF CONTENTS

    Q1  Is IRIS Inventor replacing GL?
    Q2  Is there a performance cost using a software layer on top of GL?
    Q3  Is IRIS Inventor a user interface toolkit?
    Q4  What are GLworks and Scenario?
    Q5  How is IRIS Inventor related to IRIS Explorer?
    Q6  Does Inventor have a Fortran or Ada api?
    Q7  Does Inventor require C++?
    Q8  What operating systems does Inventor require?
    Q9  How can I order Inventor documentation?
    Q10 How can I learn IRIS Inventor Programming?

QUESTIONS AND ANSWERS
--------------------------------

    Q1  Is IRIS Inventor replacing IRIS GL?

        No. GL will always have its place as a lean and mean
        rendering library that provides low-level, immediate-mode
        access to the frame buffer. Some applications will
        prefer the GL frame buffer model to work. However, if you
        are writing 3-D applications that require intensive user
        interactivity, a 3-D database, 3-D data exchange, picking,
        3-D object printing, or a common "look-and-feel", IRIS
        Inventor can save an enormous amount of time.

    Q2  Is there a performance cost using a software layer on top of GL?

        Sometimes. Note that few GL programs achieve peak graphics
        performance. This is because most applications have
        natural application overhead (CPU limited), and also
        because many programmers lack a solid understanding of
        the details and eccentricities of GL. If you are writing
        a simple display-only, immediate-mode GL program, then it
        will run faster using straight GL, but not much.
        However, if your program has scene traversal,
        interactivity, picking, bounding box calculations, and
        other object space tasks, then Inventor will perform
        better for you. This is because Inventor is specially
        tuned to make optimal use of GL on each SGI machine.
        Furthermore, Inventor supports render caching which
        results in 100% GL peak performance in most cases.

    Q3  Is IRIS Inventor a user interface toolkit?

        Yes and no. IRIS Inventor contains mostly 3-D objects.
        There is little in the way of conventional user interface
        objects such as buttons, dialogs, and menus. However,
        Inventor includes a full-fledged event model, a framework
        designed for 2-D or 3-D user interaction, and some manip-
        ulator objects for 3-D user interface building. Note that
        the IRIS Inventor Xt Component and Utility Library
        includes some traditional 2-D user interface widgets.

    Q4  What are GLworks and Scenario?

        GLworks was one of the many names that was considered for
        the product. It was unfortunately used in an Iris Universe
        article, but later shelved. Scenario was the internal
        project name.

    Q5  How is IRIS Inventor related to IRIS Explorer?

        IRIS Explorer is an application creation system and user
        environment that provides visualization and analysis
        functionality for scientists and engineers. IRIS Inventor
        is an object-oriented toolkit for 3-D application
        programmers. Explorer's 3-D geometry file format is
        Inventor's 3-D file format. Explorer's Render Module was
        written using IRIS Inventor, and custom Explorer rendering
        modules can be written using Inventor.

    Q6  Does Inventor have a Fortran or Ada api?

        No.

    Q7  Does Inventor require C++?

        No. You can use the C api and never see or use C++.

    Q8  What operating systems does Inventor require?

        Irix 4.0.1 or greater.

    Q9  How can I order Inventor software and/or documentation?

        Call your local SGI sales representative or
        1-800-800-4SGI to order products:

          SC-Inventor-1.0 (Software on a CD, Prog. Guides, poster)
          ST-Inventor-1.0 (Software-only on 1/4" mag tape)
          M4-Inventor-1.0 (Programming Guide Vols. 1 and 2, poster)
        
    Q10 How can I learn IRIS Inventor Programming?

        SGI Technical Education offers a week-long course in
        IRIS Inventor Programming.  Call 1-800-800-4SGI to 
        sign up.  Here's the course description:

        The Inventor Programming course helps applications
        programmers master a sophisticated library of object-
        oriented 3-D building blocks designed to take advantage
        of Silicon Graphics hardware features with minimal
        programming effort.  Through extensive hands-on exercises,
        students learn to write graphics applications using a
        library of objects that can be reused, customized, and
        extended to meet new needs.

        Topics Covered:
                C++ Introduction
                Object Oriented Programming
                Inventor Database Library
                Scene Graphs
                Shapes 
                Texture Mapping
                Text - 2D and 3D
                Actions applied to Scene Graphs
                Printing from Inventor
                Interaction Library in Inventor
                X event model
                Manipulators
                Components Library for reusable modules
                Node Kits to build custom groups of objects

        Prerequisties:
                C Programming Experience
                Basic Unix and editor experience with vi or emacs

--
   David Mott mott@sgi.com (415)390-1668 Silicon Graphics Inc. (ASD) 7U-545