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Subject: 
Re: Overlapping polygons etc
Newsgroups: 
lugnet.cad
Date: 
Tue, 5 Aug 2003 16:59:44 GMT
Viewed: 
474 times
  
In lugnet.cad, Orion Pobursky wrote:
In lugnet.cad, Ross Crawford wrote:
Hi all,

I'm currently working on http://www.peeron.com/inv/parts/30518

Firstly, if there's anyone else working on this please let me know, cos I'd
rather not ;)

But in case there isn't, I have a few questions:

1. Is there an "official" policy on overlapping & intersecting polygons? I have
(so far) included several in this part, as there are many cylinders
intersecting vertical planes etc, and avoiding the overlaps would take heaps
longer and produce *many* more polygons. I realise it may cause problems with
rendering the parts transparently, but is the extra work required to "do it
right" worth it in this case?

I agree. To minimize the amount of time, try making as many small repeated
subparts as possible when creating, then inline them when done. This can also be
done as a mpd format. I have started doing this in LDAO with the last few parts
I have made. It reduces development time quite a bit.


My feeling on the matter is that while overlapping is not wrong, it should be
avoided.  I know from personal experience how time comsuming this can be.

The way I handle this is, if the adjustments are easy, do it. Also this is a
higher priority on parts that have been made transparent.(or have the
possibility)


2. Should primitives be used where they aren't exactly right, but close enough?
There's a couple of situations with this part:
a) cylinder (stud) meets horizontal plane, but plane doesnt intersect
completely, the 3-4edge primitive is very close to providing the correct
intersection line, but it's a tiny bit too big, should I use it or manually do
the intersection, which would mean some renderers which substitute the stud may
not render very well.


In this case I'd say inline the primitive and trim

Yes, I agree, or use the next smaller segment primitive 1-2edge.dat and rotate
it while also placing the other lines manually(or from inlining).


b) Open wall ends of 2-4cyli touch outside wall of part - some renderers may
show vertical lines on outside wall. However in this case, the cylinder butts up
against the bottom of a stud2a, so if I manually do the cylinder, renderers that
substitute the stud may look strange with the un-substituted cylinder below it.


The problem is that the inside wall and the outside wall are the same quad.  In
other words that wall is infinatly thin.  The proper way to model this would be
to figure out how thick the wall actually is a model accordingly

huh?
I think what he is talking about is "blocky" rendering like in POV where quads
meet a cylinder.
If this is the case, I would use a rotated 1-4cyli or two 1-4cyli and let them
overlap some into the wall.


3. Approximations - The "slots" along the side of this part are slightly more
than 8LDU high and slightly more than 10LDU deep. However the 1x4 brick with
similar slots (http://www.peeron.com/inv/parts/2653) approximates to these
sizes, I guess I should too?


This is fine as long as it is in line with other parts.

ok.


The part so far looks like its coming along fine.  Keep up the good work.

ditto.

-Orion

Paul



Message has 1 Reply:
  Re: Overlapping polygons etc
 
Thanks for your replies! (...) OK. I just thought with 24 studs being affected, the large increase in polygons may be a bad idea, but it's better to get it right. (...) AFAIK this part is only available in black, but better safe than sorry. (...) (...) (21 years ago, 5-Aug-03, to lugnet.cad)

Message is in Reply To:
  Re: Overlapping polygons etc
 
(...) My feeling on the matter is that while overlapping is not wrong, it should be avoided. I know from personal experience how time comsuming this can be. (...) In this case I'd say inline the primitive and trim (...) The problem is that the (...) (21 years ago, 5-Aug-03, to lugnet.cad)

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