de_wagter
asked on
Airfoil
I wanna make a program that draws an airfoil given a number of point (eg 20 points on the airfoil)
How can I program a SMOOTH line through these points?
I tried to find the line y = 1 + x + x**2 + x**3 ....
via the Reduced Row echelon Form of a matrix, but it is not a good option.
How can I program a SMOOTH line through these points?
I tried to find the line y = 1 + x + x**2 + x**3 ....
via the Reduced Row echelon Form of a matrix, but it is not a good option.
You can find lots of information about the B-spline (I don't know the exact algorithm) which paints a smooth line using a set of control points. It does not have to pass through these points, however. I don't know if that is what you need...?
ASKER
Sounds great:
Just need an algorithm to draw a smooth line through a set of points. (to draw an airfoil)
Just need an algorithm to draw a smooth line through a set of points. (to draw an airfoil)
ASKER
where do I find info about this B-spline?
ASKER
B-spline does not go through the given points,
do you know any other that does ??
do you know any other that does ??
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Almost no algorithm make the curve to touch control points (in fact, the smoothing process means that a bit). If you have a curve with these (numbered) points, it's impossible to draw an INNER curve (this is, not going BEYOND control points), as a Spline curve does, which touches all four points:
2 .
1 . 4 .
3 .
2 .
1 . 4 .
3 .
ASKER
it should not be an inner curve at all. That's what the B-Spline does. This means that our airfoils would become smaller than they should be.
ASKER
Perfect, that's exactly what I was looking for.
Now I just have to write some code who does the thing, and it might not be easy,
anyway: thanx for the link
Now I just have to write some code who does the thing, and it might not be easy,
anyway: thanx for the link