POV-Ray : Newsgroups : povray.binaries.images : Re: Off the drawing board Server Time
10 Aug 2024 07:20:22 EDT (-0400)
  Re: Off the drawing board (Message 1 to 4 of 4)  
From: Tom York
Subject: Re: Off the drawing board
Date: 8 Oct 2004 05:40:00
Message: <web.4166601ff4f74b2d2ff34a90@news.povray.org>
pov### [at] almostbestwebnet wrote:

> Holy carp!  That thing (space ship, I presume?)
> is amazing.  It's a masterpeice of greebles.  Wow.

Thanks! Yes, it's a space ship.

> A read ahead in this thread and you say that you
> made the ship entirely from pov-ray primatives.  Wow,
> even more.
>
> I've never done any greeblage this cool (not for
> lack of trying though)
>
> Any greeble-making tips you'de care to share?

Start simple, have patience, and don't use one particular greebling pattern
or method for the whole model (if it's large). Patience can be pretty
important - the ship has taken several years of (very low intensity) work
and is still not finished. You can see that the detail is a maximum near
the top of the forward bit of the model, but the sections towards the rear
are much lower in details. I built the big bits first and went through the
model adding smaller and finer details, although there were some
exceptions. If I find myself stalled trying to detail one part, the model
is large enough that I can move on to another. I find it helpful to render
an image of the model and see where the eye is drawn - often it's to large,
flat areas with no detailing, which can be marked down as targets for
revision. The aft part of the ship is presently in this category.

The design started very simply. I've torn up various bits of the design and
started over several times. I usually only added greebles when I was sure
that I was going to keep the large-scale geometry underneath them, although
I've had to remove greebles, large geometry and all once or twice. The
greebles themselves are usually cylinders, boxes or (sometimes) prisms in
POV-terms, and can be used to cover embarrassing joins as well. I've also
found that simply taking some relatively large-scale piece of geometry and
creating a copy by shrinking it in one direction and expanding it in
another looks good when the copy is overlaid on the original. You can see
this trick quite a lot on the model, and it gives a detailed feeling to
sections it's applied to. If used too much the eye can work out what's
going on, though, and it ends up looking quite fake as a result.

It's a good idea to produce a "person" model (in my case, a tall box with a
bright blue texture) to get an idea of the scale you should be detailing
to, and to work out how large windows should be (if you use them). A useful
trick in SDL is that you can implement a sort of level-of-detail or
layering system by just enclosing particular blocks of code in something
like this:

box {
 ... gross geometry and large-scale structure
}

#if(LOD > 50)
  ... associated details, twiddles and greebles...
#end

This makes turning excess detail on and off very easy by setting the LOD
variable at the top of your file. If you are going to use SDL for a large,
complex model you should also sprinkle comments very heavily through your
code - the ship model is about 4000 lines of SDL and has comments for most
groups of objects indicating roughly where they are in the model and what
they're supposed to be (greebles/detail blocks can look a bit more
convincing if their author thinks they have a purpose - no matter how
fanciful or insane). It can get very irritating looking for a single small
area of detailing in a few thousand lines if you haven't got comments to
search for.

It's definitely worth taking a look at sites dedicated to spaceship
modelling, since they often have tutorials on greebling (though some will
be more applicable to polygon modelling than non-mesh primitive modelling).
You can hit several of them with a well-aimed google search.
http://www.scifi-meshes.com in particular has some excellent tutorials on
greebling, although I didn't use a lot of the tricks because they would
have been difficult* with POV.

Hope this all helps, I'm still learning this stuff as I go.


Post a reply to this message

From: Ben Lauritzen
Subject: Re: Off the drawing board
Date: 8 Oct 2004 09:04:18
Message: <41669052@news.povray.org>
Just a small nitpick - that knife's adjuster thing should be closer to the
other end.  Knives like that are retractable, so there should be room to
pull the whole blade back in.


Post a reply to this message

From: povray
Subject: Re: Off the drawing board
Date: 9 Oct 2004 22:10:28
Message: <qdqgm0121rt62qbvsiqv8bmg9app5c2n03@4ax.com>
On Fri,  8 Oct 2004 05:39:10 EDT, "Tom York"
<alp### [at] zubenelgenubi34spcom> wrote:

>pov### [at] almostbestwebnet wrote:
>
>>
>> Any greeble-making tips you'de care to share?
>
>Start simple, have patience, and don't use one particular greebling pattern

<snippage>

Thank you!  That info has been saved!

So far the only way I've gotten greebles of
any interest was either by making "tiles" in
wings3d, or by random processes via pov-ray macros.
Both the tile aproach and the random approach tend
to not really look that good ... although I have
one set of tiles that approximates the look of the
Death Star.  But how many times do you need to
render a death star landscape?  :D

So I am doubly awed that you did it the hard way, by
hand, over a long time.

>Hope this all helps, I'm still learning this stuff as I go.
>

Again, thank you.  I've been using pov-ray since 1990
(back then it was called DKB render (Did you know it was
originally first written for the Amiga?)) and I've not
got stuff as good as your picture.  Kudos!


Post a reply to this message

From: Tom York
Subject: Re: Off the drawing board
Date: 11 Oct 2004 03:55:00
Message: <web.416a3c4af4f74b2d2ff34a90@news.povray.org>
"Ben Lauritzen" <loo### [at] austinrrcom> wrote:
> Just a small nitpick - that knife's adjuster thing should be closer to the
> other end.  Knives like that are retractable, so there should be room to
> pull the whole blade back in.

Ah, oops. I'll replace the version on the website (tomorrow), rather than
post it here. Well spotted!


Post a reply to this message

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.