
			*******************
			*     CAD2RAD	  *
			*   Version 1.0   *
			*		  *
			*	by	  *
			*   G.Moreillon	  *
			*		  *
			*    July 1992	  *
			*******************



CAD2RAD USER'S MANUAL
=====================


1.  Introduction
    ------------

    Cad2rad is an AutoCad to Rad file converter. It reads a text file in
    AutoCad format and writes out a text file in Rad format.

2.  What is converted
    -----------------

    Not all AutoCad entities are converted by Cad2rad. As a matter of fact,
    only 3D Faces, Solids and Traces are supported. Thus, if you want to build
    a scene using AutoCad, be careful only to use those primitives.
    All other entities are ignored.

    AutoCad Layers are converted to Pure objects. This may not be geometricaly
    interesting, since Layers can be quite independant from geometry (at least
    that's how I understand it), but from the few .dxf files I've seen, Layers
    where the most used grouping entities.

3.  Running Cad2rad
    ---------------

    To run Cad2rad, type:

	cad2rad <infile.dxf> <outfile.rd>

    The first file must be in AutoCad format (.dxf) and the second will be
    written in Rad format (.rd).

4.  The generated file
    ------------------

    The generated file is directly readable by Rad or Preprad, but it is not
    actually usable by Rad:

     - No light sources are defined
     - All objects have the same material
     - Objects are most likely to be too big (one object includes several
       others). It comes from the conversion of Layers into Pures.
     - No hierarchy is defined between the objects
     - Some normals are likely to be facing the wrong way
     - Some polygons are likely to be doubled

    All of this has to be fixed using Preprad, thus, as soon as the conversion
    is done, do not attempt to feed the file to Rad, but prepare it with
    Preprad first.
