Browse Prior Art Database

New Data Flow to Three Dimensional Graphics Adapters

IP.com Disclosure Number: IPCOM000117066D
Original Publication Date: 1995-Dec-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 76K

Publishing Venue

IBM

Related People

Aranda, M: AUTHOR [+3]

Abstract

This article describes a new data flow for 3D graphics adapters. Contrasts between the current 3D data flow and the one proposed in this article are discussed as well as advantages to the new data flow. The change in the data flow although simple provides a much higher degree of modularity and significant performance gain over the current 3D data flow.

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New Data Flow to Three Dimensional Graphics Adapters

      This article describes a new data flow for 3D graphics
adapters.  Contrasts between the current 3D data flow and the one
proposed in this article are discussed as well as advantages to the
new data flow.  The change in the data flow although simple provides
a much higher degree of modularity and significant performance gain
over the current 3D data flow.

      The current paradigm for transferring 3D graphics data is for
the host CPU to send rendering commands to the graphics processor of
GP via a system for I/O bus.  The GP does the lighting and
transformation and sends the vertex and drawing commands and data to
the raster processor or RP via a private bus.  The RP does the
drawing and sends the results to the frame buffer.  Refer to Fig. 1.

      The problem arises when the host CPU needs quick access to the
frame buffer to perform pixel transfers which is very common in X. X
is the windows system used in the unix environment.  In this case,
the GP acts as a hinderance instead of an accelerator.  The host CPU
must access the RP via the GP which now is nothing more than a layer
of latency.

      Another problem with this type of data flow is the inability to
provide 3D graphics product that allow the GP as a feature.  For the
high end 3D graphics user, the lighting and transformation is
accelerated
in hardware.  For a less demanding 3D user, this operation could be
done
in software on the host CPU.  Typically, two distinct products are
needed
since the RP interface requires change.  Thus the software for the
new
stand alone RP versus the GP/RP product is often time radically
different
causing two distinct design efforts.

      Often, the I/O bus or the system bus offers a tremendous
ba...