Logiciels PC Special 5/Logiciels PC HS 5.iso/Logs/Lego/L2p/L2P.DOC

Text File | 1999-01-06 | 13.3 KB | 380 lines

l2p.doc for Version 0.51

1. General

1.0. DISCLAIMER

  LEGO(tm) is a trademark of The LEGO Group (TLG).  I am not related to TLG
in any way. POV-Ray(tm) is a trademark of the POV-Ray Team (tm).


1.1. What is l2p ?

  l2p is a converter from James Jessimans LDraw to POV-Ray.  Models created
with LDraw can be nicely rendered by POV-Ray when converted with l2p.
  l2p is (C) by Lutz Uhlmann 1997,1998.


1.2. What do I need to run l2p ?

  Of course  you need the LDraw package to create the models.  This package
is not  included,  the  most  recent  version is  available for download at
James's  homepage,  "http://silo.riv.csu.edu.au:80/~jjessiman/lego/ldraw/".
To run LDraw, you need DOS or a DOS emulating environment.
  Also  you need POV-Ray 3.0,  which is  available for various platforms at
"http://www.povray.org".
  At last  you need the  "lgeo" package  for POV-Ray.  "lgeo" is an acronym
for  "Lego Geomtrical Equivalent Objects",  this  package  defines LEGO(tm)
compatible objects and colors for POV-Ray.  All objects have are orientated
the same as in LDraw, because it was mainly desgined to work with l2p.


1.3. What should the l2p package contain ?

  This package contains at least nine files:
    go32.exe
        l2p
    l2p.exe
    l2p.doc
    l2p_colr.tab
    l2p_elmt.tab
        l2p_ptrn.tab
    light.dat
        spotlite.dat
  l2p.exe  is a  Win32 console  application version,  which should  work on
Win 95,  Win 98 and Win NT 4.0. L2p.doc is the one you read,  l2p_colr.tab,
l2p_elmt.tab  and l2p_ptrb.tab are  table files specifying  the LDraw parts
and  colors supported  by my lgeo package.  They are  essential  for l2p to
operate.  Any part or color not found in these files will not be converted.
l2p  is the  Linux ELF Binary.  Light.dat and  the spotlite.dat  are  light
sources to be used in Ledit to place lights. So copy these to files to your
LDRAW\PARTS directory and try around. The spotlite has an arrow to indicate
the direction of the light, so try some rotations.


2. How to run l2p

2.1. Location of files

  The only files  needed are l2p_colr.tab,  l2p_elmt.tab  and l2p_ptrn.tab.
They must be located in the directory from which l2p is called.  I just put
all the l2p-files in my LDraw directory.


2.2. Calling l2p

  l2p  is called  via command line  "l2p [options] <source> <destination>".
By default, if not given, a ".pov" suffix is added to the destination.  The
options accepted by l2p are:
  -f    Generate a full scene with a camera
  -h    display help.
  -i    Suffix '.inc' for generated files.
  -l    Convert LDRAW Object "light.dat" to lightsources.
  -t    Print a table of used parts (converted ones only)
  -v    Verbose, print information about piece counts etc.
  -s[n] Generate scene for each step.
        If n is given, generate file only for step n

  Each generated  file will  contain the required #include diectives to in-
clude the parts and colors from  the lgeo package to render the  model. You
just have to set up a camera and perhaps some additional lights.  Of course
you can modify the scene file to your like, perhaps include some fog, halos
or anything you want.

  New for version 0.2 is the submodel feature. For each part which does not
apply to the standard part names,  beginning with a number, a #include line
will be generated. The whole included file will be bound to one object by a
union or merge  command and textured with the color given.  So if there are
any parts in the included model with color 16, they will be colored in this
color, like in LDraw. Color 24 is not supported. Of course you will have to
convert the included models themselves, with the -i switch set to generate
".inc" suffixed files.
  There are two example files, "test_inc.dat" (submodel) and "inc_test.dat"
zipped for download iavailable at my homepage.  Main file is "inc_test.dat"
which places three of the submodels in  different partial colors on a green
baseplate.  Check these files  to get the  idea how this works.  I have not
tested it, but it should also work recursively,  with submodels in the sub-
model. I also am not sure how the results for transparent colored submodels
will be,  as I can not determine which color will be used if a part is used
with color number 16. In this case, the whole submodel is merged instead of
using a union.
  Another problem may occur with people making their own parts,  and naming
them.  They may be misinterpreted as a LDraw part when the names first char
is a digit (0-9) and not will not converted at all,  or otherwise they will
be interpreted as a submodel,  which is not available,  because it is not a
real submodel.  I have to set a break here,  so l2p will support only parts
with official LEGO(tm) parts numbers, or 'unknown' numbers given to them by
James Jessiman, the author of LDraw.  All parts not apllying to this rules
may be misinterpreted, until I rewrite l2p from scratch (maybe never).
  New for version 0.3 is the ability to work with moved part numbers. So if
you still use for example part 9 (1x8 plate) in your model, which has moved
to 3460, l2p will count and include this part as 3460.  So do not be afraid
when you use L2P with the -t table option get some part numbers you did not
use in your model.  The parts moved  are deleted from the LGEO Library with
their old numbers and only  used with the new numbers.  You should not need
to worry about  your older models,  but for the  future better  use the new
numbers.
  New for version 0.31 is the ability of generating a printout of parts not
in the LGEO Library yet. Use the "-m" option to see the missing parts.
  New for version 0.4 are patterned parts.  Therefore, a new data file with
the actually implemented patterns called "l2p_ptrn.tab" is needed.  Because
of the  limitations to a 8.3  file name,  the patterns have a file name not
matching the pattern name.  The pattern include files for POV-Ray are to be
located is the "patterns" subdirectory in your LGEO directory. If a pattern
is not available, an undecorated version of the part is used, if available.
  New for Version 0.5 is the camera  generating feature using the "-f" com-
mand line switch. Read section 2.2.7. for details.
  Version 0.51 fixes  some minor bug  in the default  camera generating and
adds the feature of directed lights.
  Version 0.52 fixes a bug  with submodels in submodels using color 16, re-
ported by Jacob Sparre Anderson.  L2P also does  not give  a table with the
stupid %NaN number when processing a file completely using submodels and no
real parts.
  Version 0.53 adds the feature for  multiple used part number or subparts,
like 3709 (Technic Plate 2x4) and 3709a (Brick 2 x 4 with holes)  as an ex-
ample for multiple parts and 89 (Technic Universal Joint),  which has to be
used separately  with 89a and 89b if a specific  angle is needed as example
for subparts.


2.2.1. -i command line switch

  If "-i" or "-I" is  specified in the command line,  instead of the ".pov"
suffix,  a ".inc" suffix is added to the  destination file name.  Note that
even "l2p -i mymodel.dat mymodel.pov" will generate a file "mymodel.inc".


2.2.2. -l command line switch

  If  you  specify  "-l" or "-L" in  the  command line,  the  LDraw  object
"light.dat" will be converted to a light source. Currently the color of the
object is not converted,  l2p just will create a white light.  This will be
changed in future  probably.  If this option is not given,  the "light.dat"
objects will not be converted.
  New in version 0.51 is the conversion of the  LDraw object "spotlite.dat"
to directed Light sources. These Lightsources emit a cone of light into the
direction of the arrow, but these lights are not as bright as normal light-
sources,  so I think a scene  just with directed  lights will be to dark in
any case.


2.2.3. -t command line switch

  The "-t" or "-T" switch will generate a table which lists the LDraw parts
converted by l2p:

  Used parts in quantity:
   Part        Part        Part        Part        Part
     28:  11    101:  12    148:  11   2431:   2   2445:   9
   3001:   2

  If more  steps of a model is converted (see -s command line switch), the
table contains the quantities of the last generated step.


2.2.4. -v command line switch

  If "-v" or "-V" is given as an option, l2p will print some general
informations about the conversion, as shown below:

  Converting mymodel.dat to mymodel.pov.
  Generating each step.
  Total Number of Steps:  1
  Total Number of Parts:  36
  Total Number of Lights: 0


2.2.5. -m command line switch

  This option lets l2p print a (unsorted) list of the parts used in your
model, which are not in LGEO now. I fear this to be a shot in my knee, as
people now will mail me for needing this one special part...


2.2.6. -s[n] command line switch

  With  the "-s" or "-S" option  specified,  l2p will generate each step of
the models as a single file instead of the complete  model in one file. The
step number will be appended to the destination file name.
  If an additional integer is specified, e.g. "-s4", only this step will be
generated. All parts used until the specified step (inclusive) will be con-
verted.


2.2.7. -f command line switch

  When specifying the "-f" or "-F" switch, l2p generates a full scene ready
to render,  with a camera about the  standard LDraw viewing  angle and some
general lights.  Do not use  this option on submodels,  since then you will
have multiple camera setups.
  When generating such a full scene,  you also cannot forget to include the
"lg_defs.inc" and "lg_color.inc" files,  which seems to  be a common source
of errors.  The camera  position is calculated by  using the maximum ranges
of parts locations,  not including the size of the parts, so it is somewhat
imperfect.  If you do not like the setup,  just use a text editor to change
the location and look_at of the camera in the generated files.
  Not that since this  is a full scene,  the maybe specified "-i" switch to
generate a "*.inc" instead  of a "*.pov" file  will be overridden,  so when
"-f" is specifid you always will get a "*.pov" file.


2.3. Colors

  The colors from LDraw are converted as shown in the list below. Any other
color number not listed will be converted to a color called "lg_undefined".
This is a light  blue with no LEGO(tm) equivalent,  so it should be easy to
detect parts with incorrect colors in your traced picture.  Color number 16
will not be textured at all, to work with the submodel feature (New for l2p
v0.2).

  LDraw Color  LEGO(tm) Color
    0          black
    1          blue
    2          green
    4          red
    5          purple (dark violet, as in Technic set 8277)
    6          brown
    7          gray
    8          dark gray
   13          pink (e.g. in Belville)
   14          yellow
   15          white
   33          clear blue
   34          clear green
   36          clear red
   42          clear neon green (fluorescent yellow)
   43          clear cyan
   44          clear neon orange (fluorescent orange)
   46          clear yellow
   47          clear white (colorless)
  334          gold (reflecting)
  382          tan (beige, desert)
  434          dark cyan (e.g. in New Technic Models)
  503          chrome (reflecting)
  506          mint (e.g. in Belville)
  509          rose (e.g. in Paradisa)
  510          light yellow (e.g. in Belville)


2.4. Parts

  The parts  defined in the lgeo  library for POV-Ray have the same name as
the LDraw parts, with a "lg_" prefix.  They also have the same orientation,
but with a  different unit size.  The scaling is done by L2P.  Just look at
the LGEO directory  to see which parts will be acknowledged by L2P.  If you
have the  latest version  of the  "l2p_elmt.tab" file,  they  should all be
known to L2P.


2.5. Error handling

2.5.1. "Cannot open file <l2p_colr.tab>" and
       "Cannot open file <l2p_elmt.tab>" and
       "Cannot open file <l2p_ptrn.tab>"

  One  of the  convert table  files could not be found.  Make sure they are
present in the directory you are working in.


2.5.2. "Cannot open Input file ..."

  The specified input file could not be opened. Check path and filename.


2.5.3. "Cannot open Output file"

  The current output file could not  be opened.  It may be existant and pro-
tected or the disk may be full.


2.5.4. "Could not allocate memory for ..."

  This may occur  for any  allocations to be made.  Building the converting
tables from  the convert table  files or reading the input file.  Free some
memory and try again.  The memory  needed for one part  from the conversion
table is  a maximum of 32 bytes,  depending on the name of  the part,  each
part from the  input file needs 68 bytes.  The color table needs about 600
bytes maximum.


3. Future plans

  What I want to implement for the future:

  Colored lights

    The color of a light  element will be translated  into a  colored light
  source for POV-Ray.

  Convert Steps without previous parts

    This  option will  only generate  the POV-Ray scene  file containig the
  parts in the  current step,  not all elements  upto this step, as it does
  now.


4. The closing

  Feel free to  contact me for any reason about l2p.  If you have some bugs
detected, describe them as exact as possible. If neccessary, send me a copy
of the LDraw file causing the error.
  Suggestions are welcome too. Also are donations.

  You can contact me by e-mail:

  [e-mail]

  Or take a look at my Homepage for latest news on L2P/LGEO:

  http://titan.informatik.uni-bonn.de/%7Euhlmann/


Have fun,

     Lutz