How could I create realistic, randomly shaped rocks (needed to be looked
at when close-up), which look like anything from small boulders and
space dust, to asteroids and planetoids. I would like to create a
ringed-planet scene (like the one in the intro to Star Trek Voyager)
with something above the rings which would reflect on to them. But as I
said, I need a close up - so I can't use spheres and get away with it ;)
Does anyone have any ideas?

Chris Harrison
http://www.ChrisHarrison.co.uk/

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Try Jan van Sickles rock include file

http://users.erols.com/vansickl/rock.htm

Mick

Chris Harrison <har### [at] btinternetcom> wrote in message
news:373D5EF5.47619F4A@btinternet.com...
> How could I create realistic, randomly shaped rocks (needed to be looked
> at when close-up), which look like anything from small boulders and
> space dust, to asteroids and planetoids. I would like to create a
> ringed-planet scene (like the one in the intro to Star Trek Voyager)
> with something above the rings which would reflect on to them. But as I
> said, I need a close up - so I can't use spheres and get away with it ;)
> Does anyone have any ideas?
>
> Chris Harrison
> http://www.ChrisHarrison.co.uk/
>

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In my macro collection, which Ken posted in povray.binaries.utilities
for me(Thanks Ken!), there is a rock macro. I created it to make small,
stream-worn stones and pebbles, but it might be useful for this.

Post a reply to this message

Chris Harrison wrote:

> How could I create realistic, randomly shaped rocks (needed to be looked
> at when close-up), which look like anything from small boulders and
> space dust, to asteroids and planetoids. I would like to create a
> ringed-planet scene (like the one in the intro to Star Trek Voyager)
> with something above the rings which would reflect on to them. But as I
> said, I need a close up - so I can't use spheres and get away with it ;)
> Does anyone have any ideas?

<OFF_TOPIC>

That scene in Voyager is, (pardon the scientific terminology) absolute and
bloody nonsense.

Look at the size of the rocks. Look at the size of Voyager. This is ok.

Now, look at the size of the entire ring, and the size of Voyager. The rings
are what? Maybe 4-5x width of Voyager?

This either means that Voyager is bloody enormous, or this is a bloody tiny
planet. Jupiter's rings are 22,000 km wide. Call me crazy, but I don't think
that Voyager is thousands of kilometers long....

Also, while the rings are ice, I imagine that the random surfaces would
result in reflections too blurred to ever make out anything.

</OFF_TOPIC>

Anyhoo... take a look at
http://www.lancs.ac.uk/postgrad/thomasc1/render/maps.htm for lots of
planetary POV stuff... Wonderful site...

Simon
http://home.istar.ca/~sdevet

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Mick Hazelgrove wrote:
> 
> Try Jan van Sickles rock include file
> 
> http://users.erols.com/vansickl/rock.htm
> 
> Mick

  Besides John van Sickles Rock include file which makes them one at a time
I also have a couple of command line utilities that I have gathered that make
several at a time. One in particular is handy for generting large volumes
of randomly scaled rocks and they are rough enough in appearence to make
a passable asteroid. Give a yell if interested.

Also check out the rock maker utility from Steven Pigeon at:

http://www.iro.umontreal.ca/~pigeon/


-- 
Ken Tyler

mailto://tylereng@pacbell.net

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Wow - I wasn't expecting that many replies! I was about to say, forget it
I've found a cool utility. It's from the maker of gForge, called ast_gen and
orb-cyc - seems to look good. But I'll have a look at that .inc file.

Thanks :)

Chris Harrison
http://www.ChrisHarrison.co.uk/

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there is a very good utility for truspace that generates boulders is COB
format, they can be converted to anything after using 3dwin, i havn't got it
any more, but you should fine is on any on the tsx archives - oh and its
freeware to.

Rick

Chris Harrison <har### [at] btinternetcom> wrote in message
news:373D5EF5.47619F4A@btinternet.com...
> How could I create realistic, randomly shaped rocks (needed to be looked
> at when close-up), which look like anything from small boulders and
> space dust, to asteroids and planetoids. I would like to create a
> ringed-planet scene (like the one in the intro to Star Trek Voyager)
> with something above the rings which would reflect on to them. But as I
> said, I need a close up - so I can't use spheres and get away with it ;)
> Does anyone have any ideas?
>
> Chris Harrison
> http://www.ChrisHarrison.co.uk/
>

Post a reply to this message

Simon de Vet <sde### [at] istarca>
>
> That scene in Voyager is, (pardon the scientific terminology) absolute and
> bloody nonsense.
>

    Um, is that supposed to be Saturn? I assumed it was some smaller ringed
planet on the other side of the galaxy...

    I love that scene! I even like the impossible sounds.

    I find that it is important for me to use my 8 year old mind while
watching TV science fiction. I save my 16 year old mind for reading Science
Fiction and only use my 43 year old mind for writing Science Fiction.

Post a reply to this message

Bill DeWitt wrote:

> Simon de Vet <sde### [at] istarca>
> >
> > That scene in Voyager is, (pardon the scientific terminology) absolute and
> > bloody nonsense.
> >
>
>     Um, is that supposed to be Saturn? I assumed it was some smaller ringed
> planet on the other side of the galaxy...

Well, Smaller with the emphasis on the Small part... we're talking about a
teeny-tiny planet here...  Suppose the ratio of Planet size to Ring size is
roughly constant. Jupiter is 71400km(planet diameter):114000km(ring width, inner
radius to outer radius) This is roughly 1:1.5. Now, suppose Voyager is about
500m long (more or less). The ring is no more than 6x it's width. This would
mean a ring 3km wide. Now, this would result in a planet 2km in didmeter. Think
about that :)

Now, to be generous, the thickest part of Jupiter's rings are only 22000 km
across. I'll suppose that this is what the visible rings on Voyager are,
resulting in a new ratio of 71400:22000, or 3.25:1 (big difference). However,
even this firendly estimate results in a planet about 20km in diameter. Still
far to tiny...

The fact is that no matter how you analyze the scene, no matter how generous you
can be, the planet always ends up being too small.

>     I love that scene! I even like the impossible sounds.

I do to! Wonderful looking scene... captures the essence of trek, whatever that
is...

>     I find that it is important for me to use my 8 year old mind while
> watching TV science fiction. I save my 16 year old mind for reading Science
> Fiction and only use my 43 year old mind for writing Science Fiction.

I agree! But my problem arises only here, when one mind (My trek mind) is forced
into direct competition with my other mind (my rendering/physics mind).
Unfortunately, my rendering mind won this round....

BTW, you write SF? Any available to read?

Simon
http://home.istar.ca/~sdevet

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On Sat, 15 May 1999 17:27:54 +0100, Chris Harrison
<har### [at] btinternetcom> wrote:

>I've found a cool utility. It's from the maker of gForge, called ast_gen and
>orb-cyc - seems to look good.


  Those would be John P. Beale's utilities. Be sure to drop John a
line if they work for you, or even if you have a question about their
usage not covered in the docs, as John has always been gracious in
responding to e-mail (his time permitting).
-- 
Alan
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