Cubic bezier curve : get sub curve coordinates

[Nabeshin4]

cubic bezier curve : get "sub curve" coordinates

Hi,

I have a standard cubic bezier curve defined by 4 points, what I'm trying to get is a "sub-curve" of this one (from the same point of origin, to one particular point on this curve, with the same curve).

For example, getting the first 10% from this curve, also defined as a bezier curve by 4 points, getting point of origin and end point is easy, but I really have no idea of how to calculate the position of the 2 other points (the points giving directional information). Any idea/hint of how to calculate this ?

 

[AlephZero]

The standard method is http://en.wikipedia.org/wiki/De_Casteljau's_algorithm

You might find the animations in http://en.wikipedia.org/wiki/Bézier_curve , which show how you can construct any point on a curve geometrically using a sequence of straight lines, help to explain how it works. Or Google for other websites, now you know what the algorithm is called.

 

[Nabeshin4]

Thanks a lot, that's exactly what I was looking for.