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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 What is IRIS Inventor?
- Q2 Is IRIS Inventor replacing GL?
- Q3 Is there a performance cost using a software layer on top of GL?
- Q4 Is IRIS Inventor a user interface toolkit?
- 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?
- Q11 Will Inventor use OpenGL?
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- QUESTIONS AND ANSWERS
- --------------------------------
-
- Q1 What is IRIS Inventor?
-
- IRIS Inventor is an object-oriented 3-D toolkit offering
- a comprehensive solution to interactive graphics programming
- problems. It presents a programming model based on a 3-D
- scene database that dramatically simplifies graphics
- programming. It includes a rich set of objects such as
- cubes, polygons, text, materials, cameras, lights, trackballs,
- handle boxes, 3-D viewers, and editors that speed up your
- programming time and extend your 3-D programming capabilities.
-
- IRIS Inventor:
- . introduces a simple event model for 3-D interaction
- . defines a standard file format for 3-D data interchange
- . provides high performance object picking and rendering
- . is window system and platform independent
- . supports PostScript printing
- . encourages programmers to create new customized objects
- . is fun to use
-
- Q2 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.
-
- Q3 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, and also because many
- programmers lack a thorough 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 peak GL performance in most cases.
-
- We have found that in many cases, Inventor programs run
- FASTER than the original GL program, and that the
- programmer productivity increases easily outweigh the
- overhead of the toolkit.
-
- Q4 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.
-
- 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?
-
- IRIS Inventor 1.0 and 1.0.1 requires 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-1.0.1 (Software on a CD, Prog. Guides)
- ST-Inventor-1.0.1 (Software-only on 1/4" mag tape)
- M4-Inventor-1.0.1 (Programming Guide Vols. 1 and 2)
-
- Q10 How can I learn IRIS Inventor Programming?
-
- SGI Technical Education offers a week-long course in IRIS Inventor
- Programming. 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.
- Call 1-800-800-4SGI to sign up.
-
- 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
- Interaction 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
-
- Q11 Will Inventor use OpenGL?
-
- IRIS Inventor 2.0 (due out Q3-Q4 CY`93) will use OpenGL.
-
- --
- Gavin Bell <gavin@krypton.asd.sgi.com>
-