elliptic movement?

I have a point in 3D that should move along an elipsis where the lenght of
the elipsis should be user specified. I have a time variable that runs from
0.0 -> inf. Any ideas on how I updated the point position on an ellipsis
based on this parameter?


 0
mlt
2/28/2009 7:54:15 PM
comp.graphics.api.opengl 7072 articles. 1 followers.

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mlt a �crit :
> I have a point in 3D that should move along an elipsis where the lenght
> of the elipsis should be user specified. I have a time variable that
> runs from 0.0 -> inf. Any ideas on how I updated the point position on
> an ellipsis based on this parameter?

Hi
That's not an OpenGL related question at all, but, if the axis of your
ellipsis is oriented according the Ox and Oy axis:
x=a.cost
y=b.sint
where a and b are the half axis.
Hope this helps
Cathy

 0
Cathy
2/28/2009 9:03:29 PM
"Cathy" <no@no.fr> wrote in message
news:49a9a6a2$0$25584$426a34cc@news.free.fr... > mlt a �crit : >> I have a point in 3D that should move along an elipsis where the lenght >> of the elipsis should be user specified. I have a time variable that runs >> from 0.0 -> inf. Any ideas on how I updated the point position on an >> ellipsis based on this parameter? > > Hi > That's not an OpenGL related question at all, but, if the axis of your > ellipsis is oriented according the Ox and Oy axis: > x=a.cost > y=b.sint What does "." mean? Is it multiply: x = a*cos(t) ?   0 mlt 3/1/2009 9:42:39 AM mlt a �crit : > > "Cathy" <no@no.fr> wrote in message > news:49a9a6a2$0$25584$426a34cc@news.free.fr...
>> mlt a �crit :
>>> I have a point in 3D that should move along an elipsis where the
>>> lenght of the elipsis should be user specified. I have a time
>>> variable that runs from 0.0 -> inf. Any ideas on how I updated the
>>> point position on an ellipsis based on this parameter?
>>
>> Hi
>> That's not an OpenGL related question at all, but, if the axis of your
>> ellipsis is oriented according the Ox and Oy axis:
>> x=a.cost
>> y=b.sint
>
> What does "." mean? Is it multiply:
>
> x = a*cos(t)
>
> ?

Hum... sorry, yes the dot means multiply.

 0
Cathy
3/1/2009 4:23:24 PM
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