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 / 3056
    Re: Clipping / CCW / CW / INVERT —Steve Bliss
   Lots of good stuff in your post, Rui! (...) (Side note: there are not actually any solids in LDraw. Only lines and polygons). (...) Actually, since LDraw doesn't do shading, transparent surfaces *can* be clipped. Only edges, the top-most solid (...) (25 years ago, 7-Oct-99, to lugnet.cad.dev)
   
        Re: Clipping / CCW / CW / INVERT —Larry Pieniazek
     (...) I believe this is incorrect, no? ALL transparent surfaces should appear, if only to make a contribution to the color that underlying surfaces appear to be (consider a trans blue surface in front of a trans yellow in front of a white... ) (...) (25 years ago, 7-Oct-99, to lugnet.cad.dev)
    
         Re: Clipping / CCW / CW / INVERT —Rui Manuel Silva Martins
      (...) I agree with this. (...) that' wright, a program supporting transparent colors correctly (using alpha blending) would do this just wright. A 3D card here would do wounders ! (did I spell that wright?) (...) Agreeing again! Rui Martins (25 years ago, 8-Oct-99, to lugnet.cad.dev)
    
         Re: Clipping / CCW / CW / INVERT —Steve Bliss
     (...) I was just pointing out that the clippability of transparent surfaces is a feature of the rendering program, and shouldn't be assumed in the description language. Steve (25 years ago, 8-Oct-99, to lugnet.cad.dev)
   
        Re: Clipping / CCW / CW / INVERT —Rui Manuel Silva Martins
   (...) Thanks! (...) I knew that ! ;) (...) LDraw doesn't, but this specification is for new Programs which are backwards compatible with Ldraw, but with a bunch of new enhancements. Check the instructions of any LEGO MODEL and you will see an (...) (25 years ago, 8-Oct-99, to lugnet.cad.dev)
   
        Re: Clipping / CCW / CW / INVERT —Gary Williams
      Rui Martins wrote in message ... (...) You mean six of one, half a dozen of the other. :) (...) it (...) Using 0 FACE CW|CCW|DS|UNKNOWN will also keep backward compatibility. Either way though, some quadrilaterals will need to be manually tweaked (...) (25 years ago, 8-Oct-99, to lugnet.cad.dev)
   
        Re: Clipping / CCW / CW / INVERT —Steve Bliss
     (...) No, thank you! (...) I don't know if I knew you knew that, but I was almost positive you knew that. And I knew most everyone else knew that, but I wasn't sure absolutely everyone knew that. ;) (...) Right. New programs may handle transparency (...) (25 years ago, 8-Oct-99, to lugnet.cad.dev)
    
         Re: Clipping / CCW / CW / INVERT —Rui Manuel Silva Martins
     (...) touche'! (...) Not exactly! If the color has any transparency, force CLIPPING OFF, irrespective of what the file TAGS inform. (SIDE NOTE) when using the tag 0 CLIPPING ON you are not informing the program that it MUST do clipping, but instead (...) (25 years ago, 8-Oct-99, to lugnet.cad.dev)
    
         Re: Clipping / CCW / CW / INVERT —Steve Bliss
     (...) Right. But that happens at rendering time, not in the description language. (...) I knew that. ;) (...) LOL Steve (25 years ago, 11-Oct-99, to lugnet.cad.dev)
   
        Re: Clipping / CCW / CW / INVERT —Leonardo Zide
   (...) No, when I look at the images I see real alpha-blended surfaces :) I've tried to turn backface culling in the transparent parts and they looked very ugly, it's better to draw everything in those cases. (...) Just a note to correct the (...) (25 years ago, 8-Oct-99, to lugnet.cad.dev)
   
        Re: Clipping / CCW / CW / INVERT —Lars C. Hassing
   (...) Do you know the reason why? The change-state-calls could cost a little overhead, but don't they just set some flags? And these flags would just cause negating an orientation test? /Lars (25 years ago, 9-Oct-99, to lugnet.cad.dev)
   
        Re: Clipping / CCW / CW / INVERT —Leonardo Zide
   (...) I once asked the same question :) Most OpenGL drivers have part of the rendering code create at runtime instead of having if/else statements for all the possible flags. When you change the state, the driver has to rebuild the code again and (...) (25 years ago, 9-Oct-99, to lugnet.cad.dev)
 

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