To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.cad.devOpen lugnet.cad.dev in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 CAD / Development / 2969
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
Leonardo Zide wrote in message <37F4ECA7.C0BFCF7D@c...com.br>... (...) I'd vote for CW for two reasons: 1) 'Clockwise' is shorter than 'counterclockwise'. 2) CW is used more often than CCW in rendering applications (to my knowledge) because the (...) (25 years ago, 1-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
(...) I can't argue with that :) (...) No way ! The front faces are CCW in 3DS Max, and quoting the OpenGL 1.2 specs. for glFrontFace() "mode: Specifies the orientation of front-facing polygons. GL_CW and GL_CCW are accepted. The initial value is (...) (25 years ago, 1-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
What if say a complient file contains anything starting with "0 CW". Any program dealing with this information could just scan for "0 CW*". We also could use a tag "0 AW*" if why ever the orientation is not clock-wice but anti-clockwice .... I think (...) (25 years ago, 2-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
Michael Lachmann wrote in message ... (...) I retract my earlier suggestion. I'd prefer to test for '0 CW-compliant' than '0 CW*' because checking for an exact string match is usually easier. Not supporting wildcards also promotes consistency. (...) (25 years ago, 2-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
Gary Williams: (...) I still think using 0 FACE ( CW | CCW | DOUBLE-SIDED | UNKNOWN ) is most practical. Play well, Jacob ---...--- -- E-mail: sparre@cats.nbi.dk -- -- Web...: <URL:(URL) -- ---...--- (25 years ago, 2-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
Jacob Sparre Andersen wrote in message ... (...) That works for me. I don't suppose there's an official standards-setting body of people charged with voting on extensions to the .dat format, is there? Maybe it's time to form one. -Gary (25 years ago, 2-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files  [DAT]
 
(...) 578 is compliant because it contains *only* subfile references, which have been verified to not mess up (C)CW-ness. But that doesn't mean the *subfiles* are compliant. It also assumes the compliant subfiles are oriented the way the author (me) (...) (25 years ago, 3-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
(...) We're it. So to speak. Steve (25 years ago, 3-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
Steve Bliss wrote in message <37f6c258.270062819@...et.com>... (...) 30 (...) Does that mean if a program would find the CW directive it can assume that every-thing in this file is compliant? E.g. the program would not have to test if possible (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
Jacob Sparre Andersen wrote in message ... (...) also (...) but (...) the (...) an (...) Is this the standard now, or at least could we make it the standard ???? Mike (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Interpreting the proposed FACE meta-command
 
Michael Lachmann wrote in message ... (...) Here's my take on the matter. The meta-command: 0 FACE <CW|CCW|DS|UNKNOWN> ...should only be used to indicate the order of the vertices of the polygons _in the file that contains it_. If A.dat has a '0 (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Re: Interpreting the proposed FACE meta-command
 
Gary Williams: (...) Very sensible (now that Steve has convinced me). (...) Hmm. I don't like it, but we have already abbreviated (counter)clockwise, so it does make sense to abbreviate double-sided too. :-( Play well, Jacob ---...--- -- E-mail: (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Re: Interpreting the proposed FACE meta-command
 
Jacob Sparre Andersen wrote in message ... (...) I was just trying to be consistent...:) I'd be just as happy if they were all spelled-out. But I'd like to avoid supporting both abbreviations and the complete spelling. Every additional test that (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
(...) That's what we're doing now--figuring out what the standard should be. Both the function and the syntax. But "standard" is an odd term in this case. In my mind the LDraw standard is defined as "code which is recognized and interpreted by (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files
 
(...) No (like Gary said). Two reasons: 1. The 0 FACE directive would be an operative switch, not a global setting. This is convenient, but it is also necessary in some cases. Most importantly, it would allow the 0 FACE meta-statement to appear (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Re: Interpreting the proposed FACE meta-command
 
(...) Why not recognize it all ways: 0 FACE ACW 0 FACE ANTICLOCKWISE 0 FACE CCW 0 FACE CLOCKWISE 0 FACE COUNTERCLOCKWISE 0 FACE CW 0 FACE DOUBLESIDED 0 FACE DS 0 FACE UNKNOWN This adds a bit to the parser, but not so much. The recommended standard (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Re: Hidden surface removal, and vertex order in part/primitive DAT files  [DAT]
 
(...) Forgot the footnote: 1- There's an interesting distinction between 'valid' and 'well-formed' contructions. LDraw will allow line-breaks as whitespace in commands, so: 1 16 0 0 0 1 0 0 0 1 0 0 0 1 3001.dat is valid, but it's not well-formed. (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Re: Interpreting the proposed FACE meta-command
 
(...) Recognizing multiple forms of the command shouldn't add much to rendering. Each file can be parsed once, and then the post-parsing results cached, for later re-reference. The FACE meta-command would be stored as an opcode and a single (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)
 
  Re: Interpreting the proposed FACE meta-command
 
Steve Bliss wrote in message <37f8c4a9.238320530@...et.com>... (...) Well, I have nothing against anticlockwise, but it's redundant. Seeing ACW where one expects CW or CCW may confuse some people. I checked the dictionary because I honestly didn't (...) (25 years ago, 4-Oct-99, to lugnet.cad.dev)

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR