Topol Manual Page
Contents
NAME
topol.lsp - Export facility from Autocad to the PolyTRIM and CLRview
Interactive 3D GIS & CAD integration and visualization tools.
DESCRIPTION
Software extension for Autocad to export data to the PolyTRIM and CLRview
Interactive 3D GIS & CAD integration and visualization tools from
the Center of Landscape Research at University of Toronto.
Autocad entities can be selected and filtered by a series of options.
Entities will be sorted by one of the three criteria color, layer or
insertion layer of blocks (toplayer) according to your choice.
The sorting results in seperate files written for every layer or color.
Other files created can be eyepoints from autocad views, positions
and masters from autocad blocks, and animation paths from autocad
3d-polylines.
Only the entities that are visible (that is their layer is on and thawed)
will be exported, even when nested in a selected block. This gives you
another method of filtering elements of your drawing especially usefull
when you want to update only part of a scene.
The layername or color number will be part of each respective filename
to make it an unique identifier. The pipe character "|" used by Autocad
within layernames associated with externally referenced blocks, as well
as the dollar sign "$" are replaced by an underscore "_" as they are
illegal or at least confusing characters for filenames on most systems.
INSTALLATION
topol.lsp can be loaded after you have copied the *.lsp, topol.dcl
and topol.mnu/x files to a location on your host which is included in
your Autocad search path. The method to specify or modify the necessary
environment variable ($ACAD) varies depending on the operating system.
You will have to quit and restart any Autocad still running for the
change to take effect.
LOADING
Load the program by entering (load "topol") at the Autocad
command prompt or automatically by activating the topol section in the
screen menu area of the associated menu file.
INTERFACE
The program is called by typing "topol" at the Autocad command prompt
or by selecting the "EXPORT" option in the associated screen menu
section.
There is a dialog box for Autocad 12 or later(?) which controls all
the necessary settings. For earlier versions the same control is
provided by text input or a screen menu section.
There are a number of toggles to switch on or off by entering "Yes"
or "No" in text mode or by selecting toggle buttons in the dialog box.
The file type toggles affect the access to the other settings.
In such a case the respective prompts will be skipped or its input
facilities in the dialog box will be greyed out and so disabled.
The entity sampling and sampling mode options can be preset from the
screen section of the associated menu file. They are remembered for
the current Autocad editing session.
The dialog box looks as follows (in OpenWindows style):
OPTIONS
Write Filetypes
This selection specifies which kind of information to export.
- Geometry
-
This is the default for it is the generic purpose
of the program. The list of sampled entity types and
the sampling mode selection are active.
- Positions
-
the locations of selected blocks will be written into
one or more position files.
- Pos+Masters
-
the locations of selected blocks will be written into
one or more position files.
The content of each selected block type will be written
into a master file.
- Eyepoint
-
This option enables a pop up list which contains the views
that have been saved previously in Autocad and the current
view. The one you select will be written to an eyepoint-file.
- Animation
-
The vertexes of the selected 3d-polyline are written to
a file in animation file format.
Sampling modes
These settings (the lower right boxed column in the dialog box) let
you specify the way the geometrical information will be converted.
- Sample entities by
-
Select the sorting method here out of one of the following.
- Color
-
The Autocad colornumber as visible on the screen.
This is the default and will help you when you organize
your drawing "visually".
- Layer
-
The layer of every subentity (the one which this entity
is created on). Choose this method if you use a conceptual
layering system independently from screen display colors.
- Toplayer
-
As above, except for entities within blocks which will be
treated as if beeing on the layer the block is inserted on.
Nested blocks will end all in the same file associated with
the layer of the outermost block.
This can be useful if you combine the use of (unnested)
block libraries with a seperate layer structuring system.
The concept of floating layers and colors within (nested)
blocks is fully supported. That means a subentity within a
block with the layer "0" and/or the color "byblock" will
appear on the layer and with the color of the containing block.
This continues recursively if the block has those properties as
well until a level with explicitly defined properties or the
top level block is reached. Freestanding entities with the
color "byblock" are drawn with color nr. 7 (white).
- Segmentation per circle for arcs
-
Arc entities and arc segments of polylines have to be segmented
for the use in Polytrim/Clrview. The value you enter here specifies
how smooth these segments will appear in the visualization.
Higher values will make smoother surfaces. The default of 16
is rather low but is set for reducing filesize. Make tests for
optimized settings because the appearance of the segments will
depend as well on the applied material properties as on the
radius of any specific arc.
Sampled Entities
The following switches (the left boxed row in the dialog box) let
you specify which entity types you wish to extract from your
drawing and what kind of surface they should display. By default
all entities that make up a surface in Autocad (recognized by the
hide and shade/render commands) are switched on.
Others that just simplify modelling but are rendered differentely
in Autocad or in Polytrim/Clrview are off and have to be enabled by the
user explicitly.
All polys should keep their orientation as created in Autocad
determined by the right hand rule.
Entities extruded by thickness will be inverted if their thickness
value (or "PDSIZE" for point entities) is negative.
The current export possibilities and their consequences are the
following:
- Planarized faces of 3DFACEs
-
3dfaces will be split to two triangular polys if not planar.
- Extruded and flat TRACEs
-
Traces will appear as a single poly or as a box if the
thickness is not zero.
- Extruded and flat SOLIDs
-
Solids will appear as a single poly or as a box if the
thickness is not zero.
- Extruded and flat CIRCLEs
-
Circles will appear as a flat poly
or as a cylinder built from a sequence of poly segments
according to the given number of segments and a flat poly
at either end if their thickness is different from zero.
- Extruded faces of ARCs
-
Arcs with a thickness different from zero will be segmented
according to the given number of segments per full circle.
- Extruded faces of LINEs
-
Lines with a thickness different from zero will appear as a
single poly.
- Extruded faces of 2D-PLINEs
-
2d-polylines with a thickness different from zero will appear
as a set of polys.
- Constant Width of 2D-PLINEs
-
2d-polylines with a starting width different from zero set in
their header entity (not the vertexes!) will appear as a
poly following the trace of the polyline with a constant
width. This option will override the following one for poly-
lines that match both categories (see below).
Together with a thickness and the respective option set this
will will result in a kind of a quadrilateral worm.
- Closed 2d-polys as POLYs
-
2d-polylines with the closed flag set in their header entity
will appear as a poly of the shape of the polyline.
polylines with a width will not follow this rule if the
previous option is chosen as well (see above).
Together with a thickness and the respective option set this
will result in a prismatic volume of the shape of the polyline.
This option is off by default.
- Faces of 3D-MESHEs
-
The Faces of 3d-poly meshes will appear as a set of
polys ignoring spline fits of any kind. Nonplanar faces
will be split into two triangles.
- Faces of POLYFACEs
-
The faces of polyface meshes (from Autocad version 11 on) will
appear as a set of polys. Nonplanar faces will be split
into two triangles. This option has no effect in environments
older than Autocad 11.
Filename prefix
The names of all output files (excluding the makefile) will start
with the string entered here. Default is the name of the drawing
file. The tilde "~" in a path name will be substituted for the
home directory ("$HOME" if present).
OK/Cancel buttons
The OK button starts the exporting after you have selected the
entities you wish to extract. The Cancel button discards all the
setting you have made and terminates the program.
In the text dialog mode you can press -C to exit any time.
DETAILS
topol.lsp is optimized for speed and memory usage as far as possible
without losing the functionality of sorting entities to seperate files.
Therefore just the entity names are stored for sorting and geometry is
ignored until later. The drawback is that entity data has to be
extracted twice, once for sorting and once for writing (and maybe
even more for nested blocks).
The geometrical transformations are executed in one pass out of an
unlimited number of nested blocks as long as no multiple inserts are
involved.
DIAGNOSTICS
Error messages and alert boxes are meant to be self explanatory.
ENVIRONMENT
Autolisp variables of global scope
- *exportnsegs*
- Number of segments per circle for arcs [int].
- *exportsmode*
- Sampling mode ["Color"|"Layer"|"Toplayer"].
- *exporttruelays*
-
Currently visible layers [list].
- *exportentlist*
- Currently sorted entities [assoc.list].
- *exportblocklist*
-
Currently sorted blocks [assoc.list].
- *valuablepolylist*
-
Currently writeable entity types [list_of_strings].
- *col*
- Color number used for graphical debugging [int].
- *topoldlgpos*
- Last position of the dialog box ['(intx, inty)].
- *topolfilelist*
- List of filetypes and values to write [assoc.list].
- *topoletypes*
- List of possible types and text entry prompts.
- *topoltypelist*
- Default list of entity types [list_of_strings].
- *topol_error*
- Exception handler [function].
- *topol_preverr*
- Old exception handler for reinstalling [function].
- *FILE*
- Current open file [filedesc].
- $REASON
- Control variable for dialog box (in fact local).
Operating system environment
- HOME
- Home directory used for tilde replacement.
- ACAD
- List of directories where Autocad looks for
FILES
Program files
- topol.lsp
- Main program source file.
- esample.lsp
- Entities sampling and conversion source file.
- vector.lsp
- Geometrical utilities source file.
- topol.dcl
- Dialog box definition file for Autocad 12.
- topol.mnu/x
- Menu file for setup with Autocad 10/11.
Additional Files
- topol.man
- This File.
- topol.README
- general info.
Data files
- <prefix>l_<layername>.pol
-
Geometry data written with the Layer or Toplayer
samplemodes set.
- <prefix>c_<colornumber>.pol
-
Geometry data written with the Color samplemode set.
- <prefix>.pos
- Position file.
- <prefix>.mas
- Master file.
- <prefix>.eye
- Eyepoint file.
REQUIREMENTS
topol.lsp is meant to run with most versions of Autocad on any hardware
Autocad runs on. Naturally, polyface meshes will not be extracted from
version earlier than 11 drawings since they simply don't exist there.
The dialog box control is unique to version 12 up to now. With other
versions the setup is done by text input and the screen menu.
CAVEATS
Since topol.lsp uses layernames to form filenames in "Layer" or
"Toplayer" mode when running on a PC under DOS you will have to choose
your layernames very carefully and/or even enter a null string for the
filename prefix. If the resulting filename is longer than 8 characters
(that is the layername is longer than 5 [!] characters) topol.lsp will
refuse to open the corresponding file.
Please note that the AME solid modelling package by Autodesk generates
surfaces with surface normals pointing to the inside of the created
volumes (at least most of the times...).
Models created with the AME Solid modelling package must have surfaces
defined with the command "SOLMESH". Otherwise they consist of only
wireframe information wich cannot be extracted by topol.lsp.
The "SOLID" entities in Autocad, which can be extracted with the
"Extruded and flat Solids" option, have nothing to do with solid
modelling or AME. These are a feature out of the 2D days of Autocad
and are just flat quadrilateral faces which appear solidly filled when
viewed from top. They form quadrilateral prisms if extruded, which can
only be done vertically to their ground plane.
BUGS
The method of assigning just one standard material to all surfaces is
rather primitive. It would be nice to have access to a library of
predefined material types or at least to extract rgb-values out of the
Autocad color numbers.
Cylinders (circles with a height) inside a scaled block are output with
unscaled diameter.
AUTHOR
Georg Mischler
SEE ALSO
Autolisp Programmers References, Reference Manuals and Customization
Guides for Autocad Versions 10/11/12, AutoDesk Inc.
Documentation on
CLRview
and PolyTrim.
LEGALESE
Copyright © 1993 Georg Mischler
Permission to use, copy, modify, and distribute this software
for any purpose and without fee is hereby granted, provided that
the above copyright notice appears in all copies and that both
that copyright notice and this permission notice appear in all
supporting documentation.
THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT EXPRESS OR IMPLIED
WARRANTY. ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR
PURPOSE AND OF MERCHANTABILITY ARE HEREBY DISCLAIMED.
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