 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Gail Shaw" <gsh### [at] monotix coza> wrote in message
news:3b15ecda@news.povray.org...
> Cool.
>
> Two points. The wells for the planets look a little too deep (compaired to
> the
> sun) and the falloff for the planets is too fast.
>
> Now do a black hole <grin>
>
> What's the isofunction you've used?
Well that's the problem isn't it... I need a function that doesn't go
vertical... I would like it to go as deep as the mass is large.
What I am using now is (for instance)...
#declare MarsMass = 15;
#declare MarsPosx = sin(clock*(2*pi))*39;
#declare MarsPosz = (cos(clock*(2*pi))*35)+4;
#declare MarsHole = sqrt(MarsMass)/5;
#local Mars = function(MarsMass/(max(
(x-MarsPosx)*(x-MarsPosx)
+(z-MarsPosz)*(z-MarsPosz)
,MarsHole)
)
) /// end function
isosurface{
function { y+Sun+Earth+Moon+Mars }
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
I was just wondering if you could do it with a 3d grid of rods on the x,y and z
plane. It would probably look something like a building construction structure.
The places where the gravity well is would then shrink the grid in that place
bending it in a warped fashion.
I tried to make a quick preview but I see now that it looks quite confusing! And
that's with only a few xy planes excluding the z plane... (this is not done in
Pov or MegaPov).
Well, maybe if the rods were further apart it would be more comprehensive.
Nekar
Post a reply to this message
Attachments:
Download 'Gravity grid.jpg' (91 KB)
Preview of image 'Gravity grid.jpg'
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Thu, 31 May 2001 09:08:36 -0400, Bill DeWitt wrote:
>
>"Gail Shaw" <gsh### [at] monotixcoza> wrote in message
>news:3b15ecda@news.povray.org...
>> Cool.
>>
>> Two points. The wells for the planets look a little too deep (compaired to
>> the
>> sun) and the falloff for the planets is too fast.
>>
>> Now do a black hole <grin>
>>
>> What's the isofunction you've used?
>
> Well that's the problem isn't it... I need a function that doesn't go
>vertical... I would like it to go as deep as the mass is large.
The problem is that the equation for gravity actually does go vertical, if
you're dealing with a point mass. The equation for gravity in a sphere
is a bit more complex, but it actually goes to zero at the center (which
means that if any of the various "hollow earth" theories were true, the
inhabitants would experience the sun's gravity without the earth's
contribution, and points on the inside of the shell would be subject to
some pretty extreme variations in their local "down" vector. If you left
your beach ball outside, it would soon be traveling at a little under
1000 MPH around the inside of the shell, tracking the sun.)
f'ups to off-topic, since I think the hollow-earth thing is an interesting
topic and it's likely to attract the most comments.
--
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbt 1}hollow interior{media{emission T}}finish{
reflection.1}}#end Z(-x-x.2y)Z(-x-x.4x)camera{location z*-10rotate x*90}
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Ron Parker" <ron### [at] povrayorg> wrote :
> >
> > Well that's the problem isn't it... I need a function that doesn't go
> >vertical... I would like it to go as deep as the mass is large.
>
> The problem is that the equation for gravity actually does go vertical, if
> you're dealing with a point mass. The equation for gravity in a sphere
> is a bit more complex, but it actually goes to zero at the center
But the problem with the formula I am using is that it goes vertical too
far from the center. The larger the mass, the wider the area of nearly
vertical descent.
As soon as my current animation finishes I will mess with it...
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Bill DeWitt" wrote:
> But the problem with the formula I am using is
> that it goes vertical too far from the center. The
> larger the mass, the wider the area of nearly
> vertical descent.
scale <1, 0.1, 1>
I also think it would look nice if the planets etc. were placed down in the
holes instead of hovering over them. That way I think it would look more
like the holes are a direct effect of the objects.
Rune
--
3D images and anims, include files, tutorials and more:
Rune's World: http://rsj.mobilixnet.dk (updated May 10)
POV-Ray Users: http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
In article <3b15ecda@news.povray.org>,
"Gail Shaw" <gsh### [at] monotixcoza> wrote:
> Now do a black hole <grin>
Those *are* black holes...he's using the equations for a point source, a
singularity. Spherical masses with a radius larger than 0 don't have
this falloff...unfortunately, I don't know the equation for the
gravitational force of a spherical body.
--
Christopher James Huff - chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/
<><
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Rune" <run### [at] mobilixnetdk> wrote in message
news:3b16a26a@news.povray.org...
> "Bill DeWitt" wrote:
> > But the problem with the formula I am using is
> > that it goes vertical too far from the center. The
> > larger the mass, the wider the area of nearly
> > vertical descent.
>
> scale <1, 0.1, 1>
That's cheating. I want something that really works.
> I also think it would look nice if the planets etc. were placed down in
the
> holes instead of hovering over them. That way I think it would look more
> like the holes are a direct effect of the objects.
I tried that and it did look better to me... but then the planets are
not on one plane. With two objects it was not too bad, but as soon as I
added a third it was obviously wrong. It looked like the earth was orbiting
the top quarter of the sun...
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Thu, 31 May 2001 15:00:06 -0400, Chris Huff wrote:
>In article <3b15ecda@news.povray.org>,
> "Gail Shaw" <gsh### [at] monotixcoza> wrote:
>
>> Now do a black hole <grin>
>
>Those *are* black holes...he's using the equations for a point source, a
>singularity. Spherical masses with a radius larger than 0 don't have
>this falloff...unfortunately, I don't know the equation for the
>gravitational force of a spherical body.
It's the integral of the one for a point source over the volume of the sphere,
of course. Not that that's useful. :)
--
#macro R(L P)sphere{L F}cylinder{L P F}#end#macro P(V)merge{R(z+a z)R(-z a-z)R(a
-z-z-z a+z)torus{1F clipped_by{plane{a 0}}}translate V}#end#macro Z(a F T)merge{
P(z+a)P(z-a)R(-z-z-x a)pigment{rgbt 1}hollow interior{media{emission T}}finish{
reflection.1}}#end Z(-x-x.2y)Z(-x-x.4x)camera{location z*-10rotate x*90}
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Chris Huff" <chr### [at] maccom> wrote in message
news:chr### [at] povrayorg...
>
> Those *are* black holes...he's using the equations for a point source, a
> singularity. Spherical masses with a radius larger than 0 don't have
> this falloff...unfortunately, I don't know the equation for the
> gravitational force of a spherical body.
Maybe these web pages have the answer, I sure don't.
http://www.ac.wwu.edu/~vawter/PhysicsNet/Topics/Gravity/AccOfGravity.html
Have a look at the gravitational force link there too.
Bob H.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Bill DeWitt" wrote:
> "Rune" wrote:
> > scale <1, 0.1, 1>
>
> That's cheating. I want something that really works.
If I have understood correctly the surface is a visualization only. How can
there be a fixed relationship between the mass and the effect it has on the
surface? May I ask what distance values and what mass values are the current
model based on? Imagine what would happen if you used another base unit for
distances but still used the same base unit for masses. Then you'd change
the sizes of your planets, and thus the holes would become larger or smaller
horizontally but keep the same depth. Or something like that...
> > I also think it would look nice if the planets etc.
> > were placed down in the holes instead of hovering over
> > them. That way I think it would look more like the
> > holes are a direct effect of the objects.
>
> I tried that and it did look better to me... but then the planets are
> not on one plane. With two objects it was not too bad, but as soon as I
> added a third it was obviously wrong. It looked like the earth was
orbiting
> the top quarter of the sun...
If you say so...
Rune
--
3D images and anims, include files, tutorials and more:
Rune's World: http://rsj.mobilixnet.dk (updated May 10)
POV-Ray Users: http://rsj.mobilixnet.dk/povrayusers/
POV-Ray Webring: http://webring.povray.co.uk
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
