Brook Monroe wrote:
> 
> The Y axis is UP?  What country did YOU study geometry in? <G> This is
> going to ruddy well make things difficult to produce in Moray, you know.
> 

Yes.  Hold up sheet of paper.  Draw x-y graph... x goes across the
bottom, y goes up the page... now add z... that goes on sheets of paper
placed in front of or behind your first page.  

Y is UP.

Regards,
Robert J Becraft
aka cas### [at] aolcom

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Robert J Becraft wrote:
> 
> Brook Monroe wrote:
> >
> > The Y axis is UP?  What country did YOU study geometry in? <G> This is
> > going to ruddy well make things difficult to produce in Moray, you know.
> >
> 
> Yes.  Hold up sheet of paper.  Draw x-y graph... x goes across the
> bottom, y goes up the page... now add z... that goes on sheets of paper
> placed in front of or behind your first page.
> 
> Y is UP.
> 
> Regards,
> Robert J Becraft
> aka cas### [at] aolcom

Personally I agree - Up with Y.

The only thing is that there is no sensible argument either way: so to
counter my own opinion, and your argument, lets say you leave this piece
of paper on the table where you drew your X and Y axis. Surely the
sensible place for the Z is perpendicular to the other two lines heading
Up.

My argument is asfloorless as the previous one, and therfore equally
floored.

Think on...

Rob

(actually rox### [at] geocitiescom)

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Dave Oxspring wrote:

> Robert J Becraft wrote:
> >
> > Brook Monroe wrote:
> > >
> > > The Y axis is UP?  What country did YOU study geometry in? <G> This is
> > > going to ruddy well make things difficult to produce in Moray, you know.
> > >
> >
> > Yes.  Hold up sheet of paper.  Draw x-y graph... x goes across the
> > bottom, y goes up the page... now add z... that goes on sheets of paper
> > placed in front of or behind your first page.
> >
> > Y is UP.
> >
> > Regards,
> > Robert J Becraft
> > aka cas### [at] aolcom
>
> Personally I agree - Up with Y.
>
> The only thing is that there is no sensible argument either way: so to
> counter my own opinion, and your argument, lets say you leave this piece
> of paper on the table where you drew your X and Y axis. Surely the
> sensible place for the Z is perpendicular to the other two lines heading
> Up.
>
> My argument is asfloorless as the previous one, and therfore equally
> floored.
>
> Think on...
>
> Rob
>
> (actually rox### [at] geocitiescom)

  BearFace and I have agreed that he and I both are right, that Z is up AND that
Y is up, and from now on, we're just going to split the difference and say X is
up, just to keep things simple. <G>

jbm!

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On Sun, 28 Dec 1997 23:11:37 -0500, Brook Monroe
<rin### [at] worldnetattnet> wrote:

>  BearFace and I have agreed that he and I both are right, that Z is up AND that
>Y is up, and from now on, we're just going to split the difference and say X is
>up, just to keep things simple. <G>

Why not just add in a W vector?

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Daniel Beeston wrote in message <34a84806.4540198@news.povray.org>...

>Why not just add in a W vector?


I think the 4th vector is T (time).

Eric Freeman

--
"Either this man is dead or my watch has stopped."
- Groucho Marx

http://www.geocities.com/SiliconValley/Heights/2354/
http://www.datasync.com/~reba/

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And we already have that in POV


-- 
Please also reply by E-mail.
Please remove the 'no spam' # from my address when replying by E-mail

Eric Freeman <eri### [at] geocitiescom> schreef in artikel
<34c7da88.0@news.povray.org>...
> 
> Daniel Beeston wrote in message <34a84806.4540198@news.povray.org>...
> 
> >Why not just add in a W vector?
> 
> 
> I think the 4th vector is T (time).
> 
> Eric Freeman
> 
> --
> "Either this man is dead or my watch has stopped."
> - Groucho Marx
> 
> http://www.geocities.com/SiliconValley/Heights/2354/
> http://www.datasync.com/~reba/
> 
> 
> 
>

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Robert J Becraft wrote:

> Brook Monroe wrote:
> >
> > The Y axis is UP?  What country did YOU study geometry in? <G> This is
> > going to ruddy well make things difficult to produce in Moray, you know.
> >
>
> Yes.  Hold up sheet of paper.  Draw x-y graph... x goes across the
> bottom, y goes up the page... now add z... that goes on sheets of paper
> placed in front of or behind your first page.
>
> Y is UP.
>
> Regards,
> Robert J Becraft
> aka cas### [at] aolcom

  Study format of U.S. Geological Survey data.  X and Y comprise map surface,
Z is altitude.  We're building a city--geography, not geometry. I rest my
case.

jbm!

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Brook Monroe wrote:

> Robert J Becraft wrote:
>
> > Brook Monroe wrote:
> > >
> > > The Y axis is UP?  What country did YOU study geometry in? <G> This is
> > > going to ruddy well make things difficult to produce in Moray, you know.
> > >
> >
> > Yes.  Hold up sheet of paper.  Draw x-y graph... x goes across the
> > bottom, y goes up the page... now add z... that goes on sheets of paper
> > placed in front of or behind your first page.
> >
> > Y is UP.
> >
> > Regards,
> > Robert J Becraft
> > aka cas### [at] aolcom
>
>   Study format of U.S. Geological Survey data.  X and Y comprise map surface,
> Z is altitude.  We're building a city--geography, not geometry. I rest my
> case.
>
> jbm!

 I say who cares.  What's important is that our scenes look good.

Maybe there should be a separate POV-City for those who want to do it the other
way.  I'd be willing to manage it, and I could usually update it once a day, if
needed.

Opinions?

~Kardal~

http://www.geocities.com/SiliconValley/2352/povpage.html

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Just some ideas I have.....

So have it so that everybody uses the vartiable "Detail" to be able to
remove parts, or the detail of the parts of their scene,
Ie, have say detail = 1 to be the highest, and so one down.
so for my current scene I could say something like
#if(Detail <3)
    do the fence
#else
   do some boxes that approximate the fence
#end
So if the Detail level is 2 or more then the fence will be created in all of
it's glory, or just four boxes that will go where the fence is.
Now if all the plots use the same method for the detail, then you could have
the Detail level defined at the top and have the value trickle down through
the plots.
Another way of doing the detail, so that everybody stays with in the same
boundies, would to make the detail level a distance, so if this part of the
plot is only move into the higher detail level if the camera is within  X
units of the object.
To do this, have the camera position defined as a vector = CameraPos
Then inside each plot use the vlength(thisobjectpos-CameraPos) to provide a
dist from the object inside the plot to the camera, so with the above
example I could change that to,
#if(vlength(FencePos-CameraPos)<5) // 5 units
    lets show the whole fence
#else
    just use the less detailed version
#end
Anyway this is just an idea.......
Now for something slightly different.....
For a river... Would this work...
Create a heightfield, flip it upside down. This would now define the river
bed.
Intersect it with a blue box that has been textured etc, and this would give
the water flowing through the river. I think ??? Not sure . Haven't tried...

Now for the axis bit.  I use the left-handed system, as I have always used a
text editor, and never bothered with a modeler. For me I have always thought
of Y as height, Don't know why, just have so for me I find it easier that
way.

And for the diminsions - I use 1 unit = 1 meter, so to make it work within
the system of 1 unit = 25 meters, I have defined a var called ScaleValue = 1
/25, and at the bottom of my file put

#declare FransPlot =
union {
    object {bit1}
    object {bit2}
    .......
    scale ScaleValue
    translate PlotPos
}

Now when I'm testing my plot I define a var called Testing and use in my
plot file
#ifdef(Testing)
    #declare ScaleValue = 1
#else
    #declare ScaleValue = 1/25
#end

etc.

BTW the usable unit range I have found in POVRay is ~ 1,000,000

Objects that are further than 1,000,000 units away from the camera
disappear, no matter how large they are. Most of the time for a small object
when it is 1,000,000 units away you wouldn't be able to see it anyway, but
if there is a large object like (eg a sun/planet) then suddenly is goes
away. I don't know yet what the smallest part of a unit that is useable, but
I don't think 25 meters to 1 unit is unrealistic. This should mean that you
could model down to around the 1cm region, or (.00004 of a unit), and that
is alot more resolution than I will probably need.

Also if you wanted to do a more detailed part of your own plot on your own
page, then change the above ScaleValue to 1 and render and wot ever you
modeled at.

Just my thoughts on the subject

Till next time.... Fran.

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Great thinking, suits me fine if ever I'm going to design a plot.
But young lads not up to that sort of thinking might burn a fuse there
;-) ye know who I'm talking about I guess.


Fran Firman wrote:

> #if(Detail <3)
>     do the fence
> #else
>    do some boxes that approximate the fence
> #end



> #if(vlength(FencePos-CameraPos)<5) // 5 units
>     lets show the whole fence
> #else
>     just use the less detailed version
> #end

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