pointFieldScalePP?

[Bonedaddy]

So nParticles can create a force field which attracts or repulses other nucleus objects to or from it. This isn't to be confused with self-collision -- we're talking nCloth objects, nRigid objects, and other nParticle objects. The scale of the field, as I understand it, affects how far away that field affects other objects. There's also controls on the effectiveness of the field over distance (sort of a customizable attenuation). These controls are also available on a per-particle basis, and that's what this attribute is used for.

[Duncan]

That's close... The pointFieldScale is a per particle multiplier of the pointFieldMagnitude value.

You can create a pointFieldScalePP attribute by hand and set it in an expression if desired. However it is easier to simply set the pointFieldScaleInput to some value. This automatically creates a pointFieldScalePP attribute and connects it to the pointFieldScale ramp. Thus you can easily do things like change the force intensity based on particle age or velocity.

The pointFieldDropoff is a ramp that multiplies the intensity of the field with distance. The left side of the ramp is zero distance and the right is defined by pointFieldDistance, beyond which the field is not applied. (note that the pointFieldDistance is defined either in worldspace or relative to the particle radius depending on the pointForceField setting)

One can do interesting things with pointFieldDropoff... Lets say the pointFieldMagnitude is negative so the effect is attractive. On the dropoff ramp create a negative entry at the left by typing -1 into selected value then add an entry in the middle with a value of 1. The field will now be attractive at far distance and repulsive at near ones. This can be used to trap particles into a fixed orbit distance( determined by the pointFieldDistance ). Thus particles from a second particle system would tend to orbit around particles of the first. One can use the fieldDropoff on nRigids and nCloth in a similar fashion to lock particles to a fixed distance from surface.

Note that if the selfAttract is not zero then it may get substantially slower as the field will also get applied between particles in the system, not just to other objects( one can make the pointFieldMagnitude zero to keep it from being applied to other objects if desired ).

Duncan

[anburaja]

thanks duncan,
for your explanation :thumbsup:.i have one more question is this attribute available for old particle system?.because it appears in the per particle attributes of the old particle system.

[Bonedaddy]

Thanks for the illumination, Duncan.

[Duncan]

That attribute won't have an effect on old particles. Any new nParticle attributes will appear in the same list(we don't have separate lists for nPariticles vs. classic).

Duncan

[anburaja]

thank you for your explanation.

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