 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Nekar Xenos <go_### [at] yahoo com> wrote:
> IMHO, would it not be possible to simulate a sphere of continually
> increasing ior towards its centre? If a ray intersects the sphere close to
> 90 degrees to the normal the ior is low because the air is very thin on the
> outside. As the angle of intersection gets closer to the circle's normal the
> ior increases because going towards the centre the ior increases. I think
> this would be the first step in the right direction.
If there is an object inside that sphere, how would you calculate where
this curved line intersects that object?
--
- Warp
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Warp" <war### [at] tagpovrayorg> wrote in message
news:43fb7e4b@news.povray.org...
> If there is an object inside that sphere, how would you calculate where
> this curved line intersects that object?
>
How about taking the ray on a circular path in one direction as the ior goes
up and changing the direction when the ior goes down resulting in an
s-shaped path.
-Nekar Xenos-
--
"The truth is out there..."
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Nekar Xenos <go_### [at] yahoocom> wrote:
> > If there is an object inside that sphere, how would you calculate where
> > this curved line intersects that object?
> How about taking the ray on a circular path in one direction as the ior goes
> up and changing the direction when the ior goes down resulting in an
> s-shaped path.
What? Did you even understand my question?
--
- Warp
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Warp" <war### [at] tagpovrayorg> wrote in message
news:44002edb@news.povray.org...
> Nekar Xenos <go_### [at] yahoocom> wrote:
>> > If there is an object inside that sphere, how would you calculate
>> > where
>> > this curved line intersects that object?
>
>> How about taking the ray on a circular path in one direction as the ior
>> goes
>> up and changing the direction when the ior goes down resulting in an
>> s-shaped path.
>
> What? Did you even understand my question?
>
> --
> - Warp
I meant to replace my intitial suggestion with the second one. Is it not
possible to test intersection of a circle with an object? Please excuse me,
but I (obviosly)don't know how a raytracer is programmed. How is
intersection of a straight ray done? I was thinking of just replacing the
formula for the straight ray with the formula of a circle.
--
-Nekar Xenos-
----------------------------------------
"The truth is out there..."
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Nekar Xenos <go_### [at] yahoocom> wrote:
> I meant to replace my intitial suggestion with the second one. Is it not
> possible to test intersection of a circle with an object? Please excuse me,
> but I (obviosly)don't know how a raytracer is programmed. How is
> intersection of a straight ray done? I was thinking of just replacing the
> formula for the straight ray with the formula of a circle.
How would a ray travelling in a circular path be any feasible way of
emulating variable ior? I'm not even sure it's physically possible to
have an object with an ior such that light travels in a circular path
through it regardless of the direction.
--
- Warp
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Warp nous apporta ses lumieres en ce 25/02/2006 06:50:
> Nekar Xenos <go_### [at] yahoocom> wrote:
>
>>I meant to replace my intitial suggestion with the second one. Is it not
>>possible to test intersection of a circle with an object? Please excuse me,
>>but I (obviosly)don't know how a raytracer is programmed. How is
>>intersection of a straight ray done? I was thinking of just replacing the
>>formula for the straight ray with the formula of a circle.
>
>
> How would a ray travelling in a circular path be any feasible way of
> emulating variable ior? I'm not even sure it's physically possible to
> have an object with an ior such that light travels in a circular path
> through it regardless of the direction.
>
Gravity lense, in any direction not directly aimed at it's center. As those don't have
a deffinite
center (each constituent object been a "center"), ray's paths looks rather like a
drunken man path.
Note to self: I need to create such a lense in POV-Ray one day.
--
Alain
-------------------------------------------------
After any salary raise, you will have less money at the end of the month than you did
before.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Alain <ele### [at] netscapenet> wrote:
> Gravity lense, in any direction not directly aimed at it's center.
Except that gravity does not make anything go in a circular path except
in very exceptional circumstances (which in case of light could happen
only at a certain distance from a black hole).
--
- Warp
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
In article <4400447f@news.povray.org>, war### [at] tagpovrayorg says...
> Nekar Xenos <go_### [at] yahoocom> wrote:
> > I meant to replace my intitial suggestion with the second one. Is it not
> > possible to test intersection of a circle with an object? Please excuse me,
> > but I (obviosly)don't know how a raytracer is programmed. How is
> > intersection of a straight ray done? I was thinking of just replacing the
> > formula for the straight ray with the formula of a circle.
>
> How would a ray travelling in a circular path be any feasible way of
> emulating variable ior? I'm not even sure it's physically possible to
> have an object with an ior such that light travels in a circular path
> through it regardless of the direction.
>
Now... A Spline Path could work though, maybe? I mean your basically just
doing the same thing you do with any object, make a determination of
where it is likely to intersect. I am sure you could find some averaging
function to determine where the bounding box intersection is for a
"straight" line that would hit the same point. As well as something to
find the final "direction". If no other objects are intersected, you just
continue the ray from that final point on the surface of the object. If
intersection tests of a bounding box for something inside is detected,
then you calculate along the spline path, until you hit. When it leaves
the interior of the object you stop doing the extra calculations and
continue on a normal strait path.
Or something more or less like that. The only real question is, given an
object, can you determine an averaged IOR for the ray and a final
direction, allowing you to shortcut the calculations when no
intersections are possible. Of course, I don't know how media might be
effected by such a thing...
--
void main () {
call functional_code()
else
call crash_windows();
}
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Patrick Elliott <sha### [at] hotmailcom> wrote:
> Now... A Spline Path could work though, maybe?
And sampling along a spline (iow. splitting the spline into very small
parts and making a whole ray-scene intersection test for each small part)
is exactly what would make it prohibitively slow.
Would it really be worth the effort?
Radiosity requires lots of sampling, but the results can be spectacular.
Media also requires lots of sampling, but the results can also be quite
spectacular. Variable IOR would probably require even more sampling, yet
I highly doubt the end result will look any spectacular.
--
- Warp
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
"Warp" <war### [at] tagpovrayorg> wrote in message
news:44014e05@news.povray.org...
> Patrick Elliott <sha### [at] hotmailcom> wrote:
>> Now... A Spline Path could work though, maybe?
>
> And sampling along a spline (iow. splitting the spline into very small
> parts and making a whole ray-scene intersection test for each small part)
> is exactly what would make it prohibitively slow.
> Would it really be worth the effort?
>
> Radiosity requires lots of sampling, but the results can be spectacular.
> Media also requires lots of sampling, but the results can also be quite
> spectacular. Variable IOR would probably require even more sampling, yet
> I highly doubt the end result will look any spectacular.
>
> --
> - Warp
Heat haze, bullet trails and sunsets can all be quite spectacular. I tried
doing a planetary scene coming in from outer space and landing on the
planet. I got double sun mirages at stages, maybe variable ior could have
fixed it?
--
-Nekar Xenos-
----------------------------------------
"The truth is out there..."
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
