Editing Early Raytracing History

Even though the BRL-CAD computer aided design package has a very long development history by the standards of most modern software, it is actually the latest in a line of raytracing systems dating back to the 1960s.  Much of that history is documented in technical reports from the Ballistic Research Laboratory (later the U.S. Army Research Laboratory.)  A first hand account of Richard Hoyt's earliest work on vehicle shotline calculations by Davidson C. Hardison can be found in [http://www.arl.army.mil/arlreports/1999/ARL-SR-90.pdf ARL-SR-90], starting at the bottom of page 29.  Although the report does not explicitly date Hoyt's work, from context it appears to have taken place in the mid to late 1950s.  This account details what may very well be the first true raytracing of a geometric model, done quite literally ''by hand!''  Although not computerized, this work appears to be the original foundation on which all of the Ballistic Research Laboratory's subsequent computerized raytracing systems were designed - if anyone knows more about this very early work and whether any records of it still survive, the BRL-CAD developers would be quite interested to see it!


= MAGIC =

The very first computerized raytracer at BRL was the MAGIC system, developed by 
Mathematical Applications Group, Inc. (MAGI) in the mid 1960s for the Ballistic Research Laboratory.  Richard Hoyt is listed as BRL's technical supervisor on the project.  MAGI later went on to play a [https://design.osu.edu/carlson/history/tree/magi.html significant role] in the commercial development of CGI.  The seminal report detailing this work is "A Geometric Description Technique Suitable for Computer Analysis of Both the Nuclear and Conventional Vulnerability of Armored Military Vehicles," published in 1967.  It was not approved for public release until much later, and hence is relatively obscure despite its historical importance in the field of computer graphics.

The other significant sources of information known to exist about the first MAGIC system are a set of manuals prepared by the Joint Technical Coordinating Group for Munitions Effectiveness (JTCG/ME) in 1970-71 and the proceedings of the first (and apparently last?) conference held for the users of the MAGIC and SAM-C codes in 1971.  

{| border=1 
!Report Title
!Number
!Date
|-
|[http://brlcad.org/... A Geometric Description Technique Suitable for Computer Analysis of Both the Nuclear and Conventional Vulnerability of Armored Military Vehicles]
|MAGI-6701
|1967
|-
|[http://brlcad.org/... MAGIC Computer Simulation - Volume I. User Manual]
|61 JTCG/ME-71-7-1
|1970
|-
|[http://brlcad.org/... MAGIC Computer Simulation - Volume II. Analyst Manual Part 1]
|61 JTCG/ME-71-7-2-1
|1971
|-
|[http://brlcad.org/... MAGIC Computer Simulation - Volume II. Analyst Manual Part 2]
|61 JTCG/ME-71-7-2-2
|1971
|-
|[http://www.dtic.mil/dtic/tr/fulltext/u2/728124.pdf The First Conference of Users of the Magic and SAM-C Programs]
|AD728124
|1971
|}

(Note:  Subsequent reports mention something called the SHOT GENERATOR Computer program that appears to date to around the same period as MAGIC, but I currently have no information about this code, the JTCG/ME reports that document it, or what role it played - it is referenced as an influence in the GIFT code design, so more information (if available) would be interesting.)


= GIFT =

Geometric Information for Targets (GIFT) succeeded MAGIC as BRL's primary raytracer.  By 1975, the first volume of a GIFT user manual had been published documenting the new system.  The second volume followed in 1979.

{| border=1 
!Report
!Number
!Date
|-
|[http://brlcad.org/... The Gift Code User Manual. Volume I. Introduction and Input Requirements.]
|BRL-1802
|1975
|-
|[http://brlcad.org/... The Gift Code User Manual. Volume II. The Output Options.]
|ARBRL-TR-02189
|1979
|}


Unlike MAGIC, which apparently lasted only a couple years, GIFT was in production use at BRL for a long period of time.  Consequently, there are a significant number of reports that detail uses of the GIFT system and the development of solid modeling at BRL during the GIFT years.

{| border=1 
!Report
!Number
!Date
|-
|[MIFT: GIFT Combinatorial Geometry Input to VCS Code.]
|ADA037898 
|MAR 1977
|-
|[http://www.dtic.mil/dtic/tr/fulltext/u2/a161828.pdf A Combinatorial Geometry Target Description of the High Mobility Multipurpose Wheeled Vehicle (HMMWV)]
|BRL-TR-2686
|October 1985
|}

= BRL-CAD =

The final transition from GIFT to BRL-CAD was accomplished in (??).  A number of reports in this era deal with solid modeling as a technique more than the specifics of BRL-CAD vs. GIFT, and so may reasonably be regarded as applying to both.

{| border=1 
!Report
!Number
!Date
|-
|
|
|
|}


= Other Early Computational Analysis Efforts =

== The Air Force's MAGIC System ==

Although it is not a direct ancestor of BRL-CAD, Bell Aerospace was also developing an early computer based analytical system in the late 1960s and early 1970s for the Air Force Flight Dynamics Laboratory called MAGIC:

{| border=1 
!Report
!Summary
|-
|[http://www.dtic.mil/docs/citations/AD0685190 MAGIC: An Automated General Purpose System for Structural Analysis. Volume 1.]
|Engineer's Manual
|-
|[http://www.dtic.mil/docs/citations/AD0691893 MAGIC: An Automated General Purpose System for Structural Analysis. Volume 2.]
|User's Manual
|-
|[http://www.dtic.mil/docs/citations/AD0685191 MAGIC: An Automated General Purpose System for Structural Analysis. Volume 3.]
|Programmer's Manual
|-
|[http://www.dtic.mil/docs/citations/AD0726564 MAGIC II: An Automated General Purpose System for Structural Analysis. Volume 1.]
|Engineer's Manual (Addendum)
|-
|[http://www.dtic.mil/docs/citations/AD0726565 MAGIC II: An Automated General Purpose System for Structural Analysis. Volume 2.]
|User's Manual
|-
|[http://www.dtic.mil/docs/citations/AD0726566 MAGIC II: An Automated General Purpose System for Structural Analysis. Volume 3.]
|Programmer's Manual
|-
|[http://www.dtic.mil/docs/citations/AD0755368 MAGIC III: An Automated General Purpose System for Structural Analysis Volume 1.]
|Engineer's Manual
|-
|[http://www.dtic.mil/docs/citations/AD0755369 MAGIC III: An Automated General Purpose System for Structural Analysis. Volume 2.]
|User's Manual
|-
|[http://www.dtic.mil/docs/citations/AD0755370 MAGIC III: An Automated General Purpose System for Structural Analysis. Volume 3.]
|Programmer's Manual 
|}