| Basic Info | |
|---|---|
| Media Type | model |
| subtype | vnd.parasolid.transmit.text |
| Registered? | Yes |
| See also | Parasolid |
| Extensions | |
Tags: (none)
File Formats: (none)
(last updated 2002-08-20) Name : Parasolid E-mail : [email protected] MIME media type name : Model MIME subtype name : Vendor Tree - vnd.parasolid.transmit.text Required parameters : (none) Optional parameters : (none) Encoding considerations : File content is mostly 7-bit US-ASCII text, only printable characters plus whitespace, but it can contain 8-bit characters on occasion (anything except NULL characters). Maximum line length is 80 characters (not including LF). However, when written to disk the file always uses UNIX line-ending conventions: line endings are indicated by a single LF ("\n") character, regardless of the line-ending conventions used by the platform the file is being written on. As a result, both the 7-bit and 8-bit encodings are unsuitable, and the file must be treated as binary data. The best encoding to use is likely to be quoted-printable, since the file contents is mostly 7-bit ASCII; obviously base64 will work, but it will typically result in slightly larger message sizes than quoted-printable. Security considerations : A corrupted or maliciously created file might possibly be able to crash a particular solid-modelling program that read it in, and in the presence of buffer-overrun or similar bugs in a particular solid modeller on a particular platform it might be possible to exploit these. Most applications that interpret the file format use the Parasolid kernel to do so, and that is written to be very cautious about the possibility of file corruption, but it still may be possible to generate a file that will crash it. However, short of crashing the program reading the file, the format just contains geometric and topological model data, and has no executable or scripted content and no features relating to disk or network access, so there should be no way to use it to send viruses or similar malicious code. Interoperability considerations : This file format is used by just about all solid modellers based on the Parasolid kernel. Details of the format may change with versions of the Parasolid kernel, but newer versions can always read in files written by older versions (though not necessarily vice versa). Translators to and from other solid-modelling file formats, including STEP, Pro-Engineer, IGES, and Catia are commercially available, though such conversion is typically lossy and on occasion may fail. Published specification : This is available in PDF on request from UG Solutions marketing: see http://www.ugsolutions.com/products/parasolid/top_level/contact.shtml to locate the Marketing Representative for your region. For a short while after the submission of this application it can also be downloaded from: http://www.parasolid.com/downloads/xt_download.shtml Applications which use this media : Solid modelling software that uses the Parasolid kernel (currently over 200, see http://www.ugsolutions.com/products/parasolid/customers/ps_cad.shtml and linked pages for a selection), plus suitable solid-modelling file format translators. Additional information : 1. Magic number(s) : (complex: see comment) 2. File extension(s) : .X_T (recommended), .xmt_txt (deprecated) 3. Macintosh file type code : none: as far as we know no current Mac apps read the format The first 3 lines of text in the file are always: **ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz***************** ***********PARASOLID!"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~0123456789********* *******************PART1; The lines will normally be separated by single LF ("\n") characters. In addition, the following 3 lines of text are always found in the file somewhere near the beginning, in the order given, though they may have other data between them: **PART2; **PART3; **END_OF_HEADER******************************************************** ********* The next line always begins with a 'T': this is the only thing that distinguishes the header from that of the related .X_B format, where this line always begins with a 'B'. Again, these lines are normally terminated by single LF ("\n") characters. Person to contact for further information : 1. Name : Parasolid 2. E-mail : [email protected] Intended usage : Common Exchanging solid-modelling data, particularly for CAD/CAM applications. Author/Change controller : John Juckes <[email protected]> Change History -------------- 2002-08-20 Changed contact information from 2. John Juckes <[email protected]> and Roger Dearnaley <[email protected]> to 2. Parasolid <[email protected]>