Kangaroo

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THIS FORUM IS NO LONGER ACTIVE. PLEASE POST ANY NEW QUESTIONS OR DISCUSSION ON:

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The discussions here are preserved for reference, but new questions posted here are likely to go unanswered.

Kangaroo is a Live Physics engine for interactive simulation, optimization and form-finding directly within Grasshopper.

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Pinching Fabric

by Arthur Mamou-Mani

Feb 17, 2013

Hi Guys,

Trying to reproduce the act of pinching fabric using Kangaroo (file attached and image below for guidance).

source: revolutionthreepointoh.wordpress.com

For the fabric I have defined springs on all the mesh edges and the diagonal of their faces with a restlength equal to their length. For the pinching I have tried the two techniques below so far:

1) Moving pinch points as anchor points towards each other.Result below:

2) Creating springs with rest length of 0 between pinch points.

Result below

In both cases, the mesh stayed flat instead of bending with the pinch which would happen in physical tests. In the first case, the mesh edges also got elongated which would not happen in real life.

Do you have any advice how I could get this to work please?

Many thanks,

Arthur

  • up

    Daniel Piker

    Hi Arthur,

    If you have some geometry all in one plane, and apply forces in the same plane, then the result will stay in that plane.

    In real life, if you compress a sheet in plane, there are always imperfections and asymmetries that cause it to buckle one way or the other, but in the simulation these are missing.

    Moving one vertex out of plane by a tiny amount, or adding a small out of plane unary force should solve this.

    1

    Feb 17, 2013