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An increase in mass impedes acceleration for a given constant force.
Drag is a force opposing the direction of motion. Drag is velocity sensitive: the larger the velocity, the greater the effect of drag. It’s useful for limiting the velocity of particles.
This POP is similar to with wind force; however it does not accelerate particles to a maximum speed. The Force POP applies a constant directional force.
Use the Property POP to set "physical" attributes of particles such as mass and drag.
This operator modifies the following attributes:
See the Wind POP for different kind of directional force you can apply separately or in combination with this operator.
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.
Path of an object from whose transform to extract the force direction. Overrides the Force parameter below.
Strength of the force along each axis.
Scaling factor for the force.
Ignores any mass attributes on the input particles.
Replaces any mass attributes on the input particles with the value of the Mass parameter below.
Mass to use when Override mass is on.
The parameters on this tab add randomness to the force. This makes particles more or less affected at random, creating a less uniform effect.
Seed value for the random turbulence generator.
Number of iterations of fractal noise to add.
Scale of noise added with each iteration.
Noise attenuation exponent.
Spatial frequency of noise field in X, Y, and Z.
Maximum value of noise field.
Amount to shift noise along X, Y, and Z axes.
Method used to generate noise. Hermite Interpolation and Improved Hermite are fastest.
Uses splines to interpolate values in the noise field.
More computationally expensive, but produces noise fields free of artifacts present in the Hermite methods.
Uses a more linear interpolation than Hermite interpolation.
Provides a very different look than the other noise types.
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.
The following examples include this node.
This example shows you how to calculate the average speed for each particle over a given time interval using CHOP nodes such as Vector, Trim, and Math.
Shows an RBD Simulation being attatched to a POP simulation to provide RBD style collisions to POPs.
This example demonstrates using the Convert Meta SOP to convert metaballs to polygons.