pymel.core.effects.gravity¶

gravity(*args, **kwargs)¶

For each listed object, the command creates a new field. The field has a shape which lives in the DAG and it has an associated dependency node. The field is added to the list of fields owned by the object. Use connectDynamic to cause the field to affect a dynamic object. Note that if more than one object is listed, a separate field is created for each object. If fields are created, this command returns the names of each owning shape and of the field shapes themselves. If a field was queried, the results of the query are returned. If a field was edited, the field name is returned. If no object names are provided but the active selection list is non-empty, the command creates a field for every object in the list. If the list is empty, the command defaults to -pos 0 0 0. A gravity field simulates the Earth’s gravitational force. It pulls objects in a fixed direction (generally downward) entirely independent of their position or mass. The transform is the associated dependency node. Use connectDynamic to cause the field to affect a dynamic object. If fields are created, this command returns the names of each of the fields. If a field was queried, the results of the query are returned. If a field was edited, the field name is returned. If object names are provided or the active selection list is non-empty, the command creates a field for every object in the list and calls addDynamic to add it to the object. If the list is empty, the command defaults to -pos 0 0 0. Setting the -pos flag with objects named on the command line is an error. The default for -dx -dy -dz is always the opposite of the current up direction. For example, if the current up direction is (0,1,0) (a standard Maya configuration), then the gravity default is -dx 0 -dy -1 -dz 0. The default for -a is 9.8. 9.8 meters per second squared happens to be standard Earth gravity, but in fact Maya interprets this value as centimeters per second squared. If we were to use it as meters per second squared then with default Maya units, your particles would vanish almost in the wink of an eye. If you want a different value, set it in the gravity option box.

Flags:

Long Name / Short Name		Argument Types	Properties
attenuation / att		float
	Attentuation rate of field
directionX / dx		float
	X-component of direction.
directionY / dy		float
	Y-component of direction.
directionZ / dz		float
	Z-component of direction
magnitude / m		float
	Strength of field.
maxDistance / mxd		float
	Maximum distance at which field is exerted. -1 indicates that the field has no maximum distance.
name / n		unicode
	name of field
perVertex / pv		bool
	Per-vertex application. If this flag is set true, then each individual point (CV, particle, vertex,etc.) of the chosen object exerts an identical copy of the force field. If this flag is set to false, then the froce is exerted only from the geometric center of the set of points.
position / pos		float, float, float
	Position in space (x,y,z) where you want to place a gravity field. The gravity then emanates from this position in space rather than from an object. Note that you can both use -pos (creating a field at a position) and also provide object names.
torusSectionRadius / tsr		float
	Section radius for a torus volume. Applies only to torus. Similar to the section radius in the torus modelling primitive.
volumeExclusion / vex		bool
	Volume exclusion of the field. If true, points outside the volume (defined by the volume shape attribute) are affected, If false, points inside the volume are affected. Has no effect if volumeShape is set to none.
volumeOffset / vof		float, float, float
	Volume offset of the field. Volume offset translates the field’s volume by the specified amount from the actual field location. This is in the field’s local space.
volumeShape / vsh		unicode
	Volume shape of the field. Sets/edits/queries the field’s volume shape attribute. If set to any value other than none, determines a 3-D volume within which the field has effect. Values are: none,cube,sphere,cylinder,cone,torus.
volumeSweep / vsw		float
	Volume sweep of the field. Applies only to sphere, cone, cylinder, and torus. Similar effect to the sweep attribute in modelling. Flag can have multiple arguments, passed either as a tuple or a list.

Derived from mel command maya.cmds.gravity

Example:

import pymel.core as pm

pm.gravity( 'particle1' )
# Creates a gravity field and adds it to the list of fields
# owned by particle1.

pm.gravity( pos=(-2, 0, 4) )
# Creates a gravity field at position (0,2,4) in world coordinates.

pm.gravity( 'MyGravity', e=True, att=10.4 )
# Changes the gravitational acceleration of the field called
# "MyGravity" to 10.4.

pm.gravity( dx=0, dy=1.0, dz=0.5 )
# Creates a gravity field pulling in direction (0,1,0.5) for every
# active selection. If there is no active selection, it creates this
# field at world position (0,0,0).