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This operator sets attributes on the input particles that record which other particles are closest and how far away they are.
You can also use groups containing the particles nearby (within a certain distance of) each particle. The groups are created by taking the value of the Group Name Root parameter and appending the ID of the particle the group corresponds to.
This operator modifies the following attributes:
Note the option Use point numbers instead of IDs. Point numbers are reused, while a particles ID is unique within the simulation and is not re-used. You might want to double-check this if the numbers you are getting do not seem right.
Turns this node on and off. The node is only active if this value is greater than 0. This is useful to control the effect of this node with an expression.
Note that this is activation of the node as a whole. You can’t use this parameter to deactivate the node for certain particles.
Compare against a different subset of the input particles from those specified by the Source Group parameter. Useful to find the nearest neighbor from a particular group, for example.
Add Nearest Neighbor Attribute
nearest attribute on each input particle to the ID of
the nearest particle.
Add Nearest Distance Attribute
nearestdist attribute on each input particle to the
distance to the nearest particle.
Add Number in Proximity Attribute
numproximity attribute on each input particle to the
number of particles within the distance defined by the
Proximity Radius parameter below.
Create Proximity Particle Groups
When this option is on, the operator creates new particle groups corresponding to each input particle, containing the particles closer than the Proximity Radius to that particle.
Create Groups For
Group Name Root
The base name of the new groups created by this particle. The operators names the groups by appending the ID (or point number, if Use point numbers instead of IDs is on below) of the source particle to this base name.
Include Self in Proximity Groups
Include the source particle in the proximity group.
Distance within which other particles are grouped.
Use Point Numbers Instead of IDs
Use the point number instead of IDs to indicate particles. IDs are unique to each individual particle, while point numbers refer to a position in the list of particles. In a particle system where particles are dying and points are being reused, this could mean the "nearest" particle could change as particles die (even if they're not within the Proximity Radius.
Standard POP local variables
The seconds a particle in the template has been alive.
AX AY AZ
Acceleration of the particle.
BBX BBY BBZ
The point’s relative position in the bounding box.
Point is dead.
Processing iteration number.
A collision for this particle was detected (for example, by the Collision POP) during the processing of this timestep (that is, this iteration of the particle simulation). This variable is cleared at the beginning of each timestep. Note that the collision POP actually detects any collisions which would have occurred the during the previous frame.
Percent of total life used (from 0 to 1).
Expected lifetime of particle.
MAPU MAPV MAPW
Point or vertex texture coordinates.
Total number of points.
Total number of points in source group.
NX NY NZ
The point number of the currently processed point. The
PT is not constant like
ID; it changes based on the number of points.
RESTX RESTY RESTZ
The rest position.
The sliding state of the particle.
Elasticity of a point.
Point is stopped.
1 if particle is stuck to a collision object.
TX TY TZ
Surface UV values.
VX VY VZ
Point spline weight.
Distance from particle to last collision.
HCR HCG HCB
Diffuse color at the collision point on the surface the particle collided with.
ID for last collision. You can control how this attribute is set in the Collision or Limit POP to help distinguish types of collisions.
The time at which the last collision occurred.
The texture map UV coordinates for the surface location where the last collision occurred.
HNX HNY HNZ
The normal at the surface location where the last collision occurred.
HTX HTY HTZ
World space position of the last collision.
The UV coordinates for the surface location where the last collision occurred.
Number of times the particle has collided.
Added by Color POP
Point or vertex alpha value.
CR CG CB
Diffuse point or vertex color.
Added by Property POP
Charge of the particle.
Point is clinging to geometry.
Leader to follow.
SCALEX SCALEY SCALEZ
Added by Proximity POP
Either the point number or id of the particle nearest to this one.
The distance to the nearest particle.
The number of particles within a specified proximity to this particle.
Added by Rotation POP
ROTX ROTY ROTZ
Added by Source POP
ID number, which always remains constant.
Original Source point was birthed from.
Parent’s ID Number.
Added by Speed Limit POP
Added by Sprite POP
Sprite rotation around view axis (in degrees).
Texture coordinate of sprite’s lower-left corner.
Size of sprite in texture space.
Controlled by Suppress Rule POP
Suppress default position rule.
Suppress default velocity rule.
Suppress default up-vector rule.
Suppress default aging rule.
1 if particle is suppressing its default rotation rule.
1 if particle is suppressing its default angular velocity rule.
Added by Up Vector POP
PVX PVY PVZ
UPX UPY UPZ
Absolute speed of particle.