Ubuntu Manpage: arch2rad - convert Architrion text file to RADIANCE description

Provided by: radiance_4R1+20120125-1.1_amd64

NAME

       arch2rad - convert Architrion text file to RADIANCE description

SYNOPSIS

       arch2rad [ -n ][ -m mapfile ] [ input ]

DESCRIPTION

Arch2rad converts an Architrion text file to a RADIANCE scene description. The material names for the
surfaces will assigned based on the default mapping or the mapping rules file given in the -m option. A
mapping file contains a list of materials followed by the conditions a surface must satisfy in order to
have that material.

For example, if we wanted all surfaces for blocks with RefId "thingy" and Color 152 to use the material
"wood", and all other surfaces to use the material "default", we would create the following mapping file:

default ;
wood (RefId "thingy") (Color 152) ;

All surfaces would satisfy the first set of conditions (which is empty), but only the surfaces in blocks
with RefId "thingy" and Color 152 would satisfy the second set of conditions.

Each rule can have up to one condition per qualifier, and different translators use different qualifiers.
In arch2rad, the valid qualifiers are Layer, Color, Face and RefId. A condition is either a single value
for a specific attribute, or an integer range of values. (Integer ranges are specified in brackets and
separated by a colon, eg. [-15:27], and are always inclusive.) A semicolon is used to indicate the end
of a rule, which can extend over several lines if necessary.

The semantics of the rule are such that "and" is the implied conjunction between conditions. Thus, it
makes no sense to have more than one condition in a rule for a given qualifier. If the user wants the
same material to be used for surfaces that satisfy different conditions, they simply add more rules. For
example, if the user also wanted surfaces in blocks with RefId "yohey" with Colors between 50 and 100 to
use "wood", they would add the following rule to the end of the example above:

wood (Color [50:100]) (RefId "yohey") ;

Note that the order of conditions in a rule is irrelevant. However, the order of rules is very
important, since the last rule satisfied determines which material a surface is assigned.

By convention, the identifier "void" is used to delete unwanted surfaces. A surfaces is also deleted if
it fails to match any rule. Void is used in a rule as any other material, but it has the effect of
excluding all matching surfaces from the translator output. For example, the following mapping would
delete all surfaces in the Layer 2 except those with the color "beige", to which it would assign the
material "beige_cloth", and all other surfaces would be "tacky":

tacky ;
void (Layer 2) ;
beige_cloth (Layer 2) (Color "beige") ;

If neither the -m nor the -n options are not used, arch2rad uses the default mapping file
"/usr/share/radiance/lib/arch.map". This file simply assigns materials based on color, using the
identifiers "c0" through "c255". Appropriate materials for these identifiers are contained in
"/usr/share/radiance/lib/arch.mat".

The -n option may be used to produce a list of qualifiers from which to construct a mapping for the given
Architrion file. If the -m option is used also, only those blocks matched in the mapping file will be
added to the qualifier list.

DETAILS

       Architrion blocks are divided into about 6 polygons.  The reference, opposite and end faces must  all  be
       quadrilaterals  (ie.   four-sided polygons), though one or more faces may disappear in certain degenerate
       cases.  The bottom face will usually be a quadrilateral, though it may be written out as two triangles if
       the face is non-planar or one triangle if there is a degenerate side.  The top face is treated  the  same
       as the bottom face.

       Openings  are  currently  handled  using  the  antimatter  material  type.  An antimatter material called
       "opening" is defined that "clips" all faces for the current block, and patches the edges of the hole with
       the material defined for the face "sill".  If no rule is given specifically for the sill face,  then  the
       most  specific  material  (ie.  the  material  in the latest rule) for this block is used.  An antimatter
       opening will not function properly if there is another surface intersecting it, or rendering is attempted
       from within the opening.  Overlapping openings or openings with shared boundaries will also fail.   There
       is currently no support of Architrion "frame" libraries.

       Naming  of  the  output  faces is based on layer number, reference id and output block number (sequential
       from 1 to the total number of output blocks).  If there is no reference id name, the layer name  is  used
       (if available) instead of the layer number.  If there is a reference id number but no name, that is added
       as  well.   Names are truncated to the first 12 characters, so the ends of long names may be lost.  Also,
       spaces in names are replaced by underscores ('_').  Finally, the face id is added to the end of the block
       name for each output polygon.  An example identifier for a polygon is:

            l3.window_overh.3155.ref

       This would be the reference face of output block number 3155, reference id  name  "window  overhangs"  in
       layer number 3.

EXAMPLE

       To create a qualifier list for building.txt:

         arch2rad -n building.txt > building.qual

       To translate building.txt into a RADIANCE file using the mapping building.map:

         arch2rad -m building.map building.txt > building.rad

       To create an octree directly from an Architrion file using the default mapping and materials:

         oconv source.rad /usr/share/radiance/lib/arch.mat '\!arch2rad building.txt' > building.oct

FILES

       /usr/share/radiance/lib/arch.map /usr/share/radiance/lib/arch.mat

AUTHOR

       Greg Ward