CageEdit Deformation Math


Can Someone please provide the Type info of CageEdit? (E.g bezier, B Spline, Nurbs etc )

(Dale Fugier) #2

I’m not sure I understand the question. Can you please clarify what you are looking to do and why?

– Dale


I would like to know how an object deformation occurs when a control point in CageEdit is shifted.
What is the mathematical Procedure behind the scene?

(Dale Fugier) #4

Cage editing is based on our Universal Deformation Technology (UDT).

Is that sufficient?

– Dale


As far as I found out, The UDT is a term that is only used for Rhino and it does not describe the math behind deformation.
Is the deformation based on Bezier, BSpline, Nurbs etc.?
That is what I am looking for.

(Dale Fugier) #6

Cage editing deforms the NURBS geometry.

– Dale

(Menno Deij - van Rijswijk) #7

As far as I understand it, cage editing uses a cage which is NURBS volume (i.e. with 3 parameters, u, v and w). Any captured object has its geometry described as function of the cage parameters (u,v,w), so when the location of the cage control points changes, the captured geometry is deformed accordingly.

When cage editing is used with PreserveStructure=Yes, the control points of a captured surface are described in the volume’s (u,v,w) parameters. What happens with PreserveStructure=No is not entirely clear to me; more control point lines are added to more accurately follow the deformed volume shape, but exactly how and when this happens is not documented.

If you search for the term “free form deformation” you can find a lot more information about this method.