to study some contact forces, I´m currently trying
to set up a model with two STL-surfaces penetrating
each other.
I am using “AnySurfSTL” and “AnyForceSurfaceContact”
as described in the FDK-tutorial.
Because of the special properties of my STL-data
it is necessary to transform position and orientation of
the bones.
For this purpose I tried “AnyFunTransform3DLin” as
object member of “AnySurfSTL”.

Does this work in principle?

(Unfortunately the contact forces are zero and I would like
to check this question before explaining the model
and it´s structure in detail…)

Thanks a lot


Hi Fabian,

It does work. Please check the reference manual.
Please note that if you would like to received: y=A*x+b, where A - ScaleMat, b - Offset that you want to use. You will have to transform your b to look as A’*b as the summation happens first.


Thank you very much, Pavel. The bones seem to be at the right positions in the model view. One can also watch them penetrate each other during movement but still contact forces are zero. Do you know any reasons for this problem?

Kind regards,


Hi Fabian,

It sounds as it should produce some force. What about the settings of this class? Could you define some kinematic measures to make sure that it comes in contact? If still misbehaves - you can upload your model or relevant part of it into the Debug thread and we’ll take a look at it.