ELSA GLoria-L, User Manual

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All About Graphics
ELSA GLoria-L, -L/MX, -XL, -XXL
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at the two systems hierarchically, the immediate mode is also known as the low-level
mode. The programming interface level is close to the hardware level and permits the
programmer direct access to special functions in the hardware component concerned.
The retained mode (high-level mode) makes it possible, for example, to load a defined 3D
object with textures into a Windows application. Here it can be manipulated and moved
using simple API commands. Translation takes place in real time, without the need to
know the technical structure of the object.
For further information see the Internet WWW site http://www.microsoft.com
Heidi
Heidi is a purely immediate mode interface and does not operate with a display list. This
makes it particularly suitable for application developers who already have access to
graphics libraries. Well-known CAD programs such as 3D Studio MAX/VIZ, Whip by
AutoCAD 13 and Mechanical Desktop use the Heidi system. In contrast to OpenGL, Heidi
is an object-oriented interface and thus simplifies function calls. Hardware acceleration
is achieved through standard interfaces or by means of direct hardware access to special
3D chips. Optimum performance can be achieved in this way. This API is extremely ver-
satile and flexible thanks to the many plug-ins that are available in addition to the defi-
nitions Heidi supports internally.
For further information see the Internet WWW site http://www.ktx.com
OpenGL
Following its success in gaining a good reputation amongst professionals using CAD/
CAM programs, OpenGL is now increasingly penetrating the PC market. OpenGL is plat-
form-independent and makes a distinction between immediate and display list modes. A
display list stores specific sequences that can be recalled again later. The object descrip-
tions can then be taken directly from the list, resulting in very high performance. How-
ever, if objects need to be manipulated frequently, the display list will have to be
generated again from new. In this case, the speed advantage is lost. OpenGL provides
a wide range of graphics features, from rendering a simple geometric point, line, or filled
polygon, to the most sophisticated representations of curved surfaces with lighting and
texture mapping. The some 330 routines of OpenGL provide software developers access
to these graphics capabilities:
For further information see the Internet WWW site http://www.sgi.com