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1. • CommentAuthorUbuntu
   • CommentTimeAug 21st 2010

    
   I have been experimenting with the gravitywell action for 2D emitters and I have become very confused with what exactly, epsilon is.
   The gravitywell class explains it as:
   The minimum distance for which gravity is calculated.
   * Particles closer than this distance experience a gravity force as if
   * they were this distance away. This stops the gravity effect blowing
   * up as distances get small. For realistic gravity effects you will want
   * a small epsilon ( ~1 ), but for stable visual effects a larger
   * epsilon (~100) is often better.
   It seems to me that a low epsilon causes particles to speed up and rotate more as they approach the gravitywell center. While a high epsilon causes less of this speed up and less rotation towards the center. I just need an easier to understand description of what epsilon is.
2. • CommentAuthorRichard
   • CommentTimeAug 25th 2010

    
   When the particles are very close to the center of the GravityWell, the acceleration increases to very high levels. This can cause unstable behaviour in an effect.
   
   The epsilon specifies a distance from the center of the gravity well. When particles are further away than this distance, they respond to the gravity in the normal way. The epsilon will have no effect on these particles.
   
   When particles are closer than this epsilon distance, however, the acceleration on the particles is limited to the acceleration that would be experienced at distance epsilon so the particles don't accelerate at massive rates and cause instability.
3. • CommentAuthorUbuntu
   • CommentTimeAug 27th 2010

    
   Ok I think I now get a better picture of it thank you.