To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.cad.dat.parts.primitivesOpen lugnet.cad.dat.parts.primitives in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 CAD / LDraw Files / Parts / Primitives / 250
249  |  251
Subject: 
Re: high-res sphere primitive with type 5 lines
Newsgroups: 
lugnet.cad.dat.parts.primitives
Date: 
Tue, 7 May 2002 03:30:37 GMT
Viewed: 
6247 times
  
In lugnet.cad.dat.parts.primitives, Steve Bliss writes:
> In lugnet.cad.dat.parts.primitives, Travis Cobbs wrote:
> 
> > Well, based on comments in some other threads, I came to the conclusion that
> > the type 5 lines I had around the edge of my original primitive where wrong.
> > I have now updated them accordingly.
> > 
> > This version is the same as the last other than that.  The only difference
> > lies in the control points that hang out in space off the edges of the
> > sphere.  In the previous version, I used a continuation of the sphere for
> > these control points.  In this version, I used a point projected along one
> > of the axes.
> 
> Is that true for all three edges of the sphere?

Yes.  The standard sphere primitive has type 5 lines on all three edges.
They are all necessary in order to work right (with the axis-aligned edge
control points).  My updated type 5 lines project along a different axis for
each edge, of course.

> [snip]
> > 3 16 1.000 -0.000 0.000 0.991 0.000 0.131 0.991 0.131 0.000
> [snip]
> 
> I thought you were generating to 4 decimals?  You know, like this:
> 
> > 5 24 1 0 0 0.9914 0.1305 0 1 0 -1 0.9914 0 0.1305
> [snip]

Now don't I feel stupid :-).  Especially given that not having the edges
exactly match the triangles would lead to rendering problems.  I have posted
a fixed file as a reply to my original message.

For technical reasons, I can either generate the triangles or the type 5
lines with my code, but not both at the same time.  The reason for the
screwup is that I used a previously generated file for the triangles, and
newly generated file for the type 5 lines and then just pasted the two files
together.  Obviously the original file was generated with different accuracy.

--Travis Cobbs (tcobbs@REMOVE.halibut.com)



Message is in Reply To:
  Re: high-res sphere primitive with type 5 lines
 
(...) Is that true for all three edges of the sphere? [snip] (...) [snip] I thought you were generating to 4 decimals? You know, like this: (...) [snip] Steve (25 years ago, 6-May-02, to lugnet.cad.dat.parts.primitives)

12 Messages in This Thread:





Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    

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