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Index › Programming Questions & Help › Other Libraries › Help with Physics
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Help with Physics (Read 895 times)
softhook
Help with Physics
Nov 11th, 2006, 1:23am  
I am trying to make a whole bunch of particles and then add springs as well as repulsion based on the Arboretum example. My problem comes with adding the repulsion to each of the particles. I keep getting NullPointerException errors accuring at random. What could be going wrong with this bit of code:

void addSpacersToNode( Particle p, Particle r )
{
 for ( int i = 0; i < physics.numberOfParticles(); ++i )
 {
   Particle q = physics.getParticle( i );
   if ( p != q && p != r )
     physics.makeAttraction( p, q, -SPACER_STRENGTH, 20 );
 }
}


Error messages:

java.lang.NullPointerException

at traer.physics.ParticleSystem.cleanUp(ParticleSystem.java:158)

at traer.physics.ParticleSystem.tick(ParticleSystem.java:47)

at Temporary_8936_1760.draw(Temporary_8936_1760.java:87)

at processing.core.PApplet.handleDisplay(PApplet.java:1314)

at processing.core.PGraphics.requestDisplay(PGraphics.java:564)

at processing.core.PApplet.run(PApplet.java:1409)

at java.lang.Thread.run(Thread.java:613)


Please help me out. Thanks
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