OCTOBER 1993
             
 This is version 1.0 of RRTRACER for the IBM, an easy to use ray tracing
 program.
 Requires a 386,486 with a VGA card
 Pictures generated can be saved as 640 x 480 16 colour PCX files.
 The following file needs to be in the same subdirectory as RRTRACER.EXE
 for the program to run: (They are in included in the ZIP files)
 GFABAS03.OVL      386
 GFABAS73.OVL      386 with 387 or a 486
 
 RRTRACER is written in GFA BASIC for DOS. I originally wrote this program
 for the ATARI ST which had a very nice graphic user interface which 
 GFA BASIC for ATARI used very well. I converted this for the IBM with
 minor changes, mostly to deal with the different resolutions.

 Pictures can be reviewed with any 16 colour PCX viewer. I have included
 a simple viewer PCXVIEW in the zip files.

 GENERAL OPERATION

 The opening screen presents you with a side view and top view of an empty
 room. You then proceed to add objects and lights in this space. 
 You can give the objects the properties of colour, reflectivity and/or
 transparency.When you are happy with the scene you proceed to generate 
 the 3-D ray tracing.
 This may take a long time - up to a few hours. The more objects,reflections
 and transparency the longer it takes. But the result is worthwhile. You
 can ask for a small preview picture to be produced beforehand in a shorter
 time to check the overall look of the tracing.

 NOTES ON REFLECTIONS

 Reflectivity is adjusted by a slider, values 0 (matte) to 8.
 If you want a total mirrored look, eg. a steel ball, you set the colour
 to black, and the reflectivity to 8

 NOTES ON COMPOSITE OBJECTS
 You can make a composite object out of overlapping objects. The only 
 exceptions are you cannot overlap transparent objects and you cannot have
 a light source inside an object or fatal error occurs.
 
 
 NOTES ON COLOURS

 The VGA is restricted to 16 different colours on the screen at one time.
 To ensure realistic image colouring involving reflections and transparency
 I have restricted the palette to shades of one colour (red or green or blue)
 and shades of grey and mixtures thereof.

 
 NOTES ON THE MENU


 FILE - NEW  starts a new room and erase anything done so far
 ADD  - add a sphere,light,floor,ceiling,wall,solid cylinder,hollow cylinder
        cone, or cuboid.
        Maximum 20 objects, 3 lights
 REMOVE - Remove anything added so far
 OPTION - DEEP PERSPECTIVE - makes vanishing points closer
          VIEW FROM ABOVE  - view scene from an angle above
                    LEFT/RIGHT - view scene from an angle left/right
          LOW AMBIENT LIGHT - no complete shadows
          HIGH AMBIENT LIGHT - hardly any shadows at all

 EDIT   - Edit any parameters of objects added so far   
        - PALETTE - change colours of standard palette

 GO     - START - Start the ray tracing process.
        - XYZ   - If this option is checked before START a screen is
                  displayed allowing you to modify the x,y,z coordinates
                  of the objects and lights in the picture. This is useful
                  for lining objects up vertically or for making composite
                  objects. The floor is at y=-34.4, ceiling y=+34.4
                  back wall z=-398.1, left wall x=-47.4, right wall 
                  x=+47.4


 RRTRACER IS SHAREWARE. IF YOU LIKE THIS PROGRAM PLEASE SEND $15 TO

 CLIVE PROBERT
 250 SPRINGDALE BLVD
 TORONTO, ON
 M4C1Z9
 CANADA
 416 425 6011

 I CAN ALSO BE CONTACTED ON GENIE AS C.PROBERT