[SOLVED] FixedConstraint not fixed

[Nguyen]

Hi everyone,

I used LCP, FreeAnimationLoop and FrictionContact for ContactResponse. I set some FixedConstraint to my object. When I pull the object, the fixed points still move. If I dont use FrictionContact, I dont have this problem. Any help is appreciated very much !

–Thien.

[Guebert]

Hello Thien,

I just did some tests to understand your problem, but cannot reproduce it.
It is my understanding that the use of the FixedConstraint does not depend on the use of a LCP constraint solver, as it is indeed a projection constraint. It should also not be affected by the contact response you choose.

Is it possible that a contact occurs between a fixed point and another object in your simulation ?

—
Christophe Guébert
Digital-Trainers

[Anonymous]

I have similar but different experience. I used LCP, FreeAnimationLoop, FixedConstraint and precomputeConstraintCorrection, when I changed the fix index of vertices and did not re-compute the comp file, the fixed points will float away during the simulation.
What kind of ConstraintCorrection you are using ?

[Nguyen]

I have just modified the caduceus scene file by replace the snake by my object with some fixed points. I pull the object by mouse. When my object moves through the cylinder, i.e. collision resolve is failed, then some fixed points start floating around.

[Froy]

Hello,
The LCPConstrainstSolver is flawed and FixedConstraint is not working well with it.
Replace this LCPConstraintSolver component with a GenericConstraintSolver.
The point(s) should not move anymore.

[Author]

Posts