TYPE: POP
TITLE: Resistance POP

The resistance POP computes air or water resistance on a body moving
through it. This resistance may cause the object to rotate and push it
in certain directions. This POP modifies the acceleration and torque
attributes of a particle.

The resistance is calculated on instanced geometry. If no geometry is
instanced, this POP will not alter the particle. The instanced geometry
does not need to be very complicated (it should be a simplistic
representation of the real render geometry). Complex geometry will
result in slower cook times with marginally better results.

The orientation of the geometry with respect to its direction of travel
will often determine how much resistance is applied.

Parameters:
Resistance
    Resistance - The resistive factor of the medium due to the object's
		 linear motion. Higher values produce more viscous mediums.
    Rotational - The resistive factor or the medium due to the object's
		 rotational motion. Higher values produce more viscous 
		 mediums. This value is normally the same as the value for
		 Resistance parm. You can modify it if you find your 
		 particle is either too tipsy (increase this parm) or 
		 too rigid (decrease). 
    Model      - Uses either Viscous or Newtonian model for evaluating
		 resistance. 
    Modify     - You can specify 'Position and Orientation' (both accel and
		 torque attributes), 'Position Only' (only accel) or 
		 'Orientation Only' (torque only).
    Ray Count  - The number of vectors used to compute the opposing force.
		 Geometry with fine details (like holes or thin spines) 
		 should use more rays (300 or more). 
Turbulence
    Wind Current   - A vector describing the wind direction, similar to the
		     Wind POP. 
    Add Wind Noise - You can add noise to the wind, and have it change the
		     wind direction, wind force, or both. 

    Others - The remaining parms on this page are standard Noise parms.
Geometry
    Object Type - Determines whether the object is treated as Hollow (2D)
		  or solid (3D). Solid objects MUST be closed objects, if
		  not, use Hollow.
    Divisions   - The resistance POP needs to determine the volume
		  distribution of the geometry for moment of inertia 
		  calculations. The volume is determine by dividing the 
		  space the geometry occupies into voxels. The Divisions 
		  parameter determines how many voxels are used per axis.
		  The three values of this parameter are multiplied 
		  together; do not set them to high values! (50 max). 
    Object Scale - Allows you to scale the object's geometry up or down when
		  doing resistance calculations. Larger objects will be 
		  more affected by resistance than smaller ones (with the 
		  same mass). 
    Override Mass - Allows you to override the mass attribute and specify
                    your own.
    Override Center Of Mass - Allows you to override the center of mass.
