Gravity Options

Use these options to control the behavior of your Gravity field.

Magnitude

Sets the strength of the gravity field. The greater the Magnitude, the faster the objects will accelerate in the direction of the gravitational force.

Attenuation

Sets how much the strength of the field diminishes as distance to the affected object increases. The rate of change is exponential with distance; the Attenuation is the exponent. If you set Attenuation to 0, the force remains constant over distance.

Direction X, Y, Z

Sets the direction of the gravitational force.

Distance

Use Max Distance

If you turn on Use Max Distance, connected objects within the area defined by the Max Distance setting are affected by the gravity field. Any connected objects outside the Max Distance are not affected by the gravity field.

If you turn off Use Max Distance, all connected objects are affected by the gravity field, no matter how far away they are from the gravity field.

Max Distance

Sets the maximum distance from the gravity field at which the field is exerted. You must also turn on Use Max Distance for Max Distance to take effect. Available in Attribute Editor only.

Note: By default, the gravity field and most other fields have Max Distance set to a value of -1 and Use Max Distance turned off. The -1 value for Max Distance has no effect because the Use Max Distance setting is turned off. If you turn on Use Max Distance, the -1 value has the same effect as a value of 0—no objects are affected by the field at any distance.

The -1 value is included for compatibility with previous releases of Maya. If you turn on Use Max Distance and change the value of Max Distance, you can enter a positive number only.

Falloff Curve

Available when Use Max Distance is checked.

When using a field to exert force, sometimes the object receiving the force may have trouble settling down after the force is exerted. Use this curve to modulate the force. For example, scale the field’s force so that it smoothly drops off to zero at the boundary defined by the Max Distance value.

The curve is defined within the normalized distance; in other words, 0 to 1, where 0 corresponds to the field's center and 1 corresponds to the Max Distance value. The value from the curve is a scaling factor to be applied to the force.

Note: Fallout Curve is only available as an attribute after you create the field. It is not available an a field creation option.

Volume shape

Volume determines the region where the field affects particles/rigid bodies.

Volume

Choose one of None, Cube, Sphere, Cylinder, Cone or Torus.

Volume Exclusion

When Volume Exclusion is turned on, the volume defines the region in space where the field has no effect on particles or rigid bodies.

Volume Offset X, Y, Z

Offsets the volume from the location of the field. If you rotate the field, you also rotate the offset direction because it operates in local space.

Note:

Offsetting the volume changes only the volume’s location (and therefore, which particles the field affects). It does not change the actual field location for purposes of computing field force, attenuation, etc.

Volume Sweep

Defines the extent of rotation for all volumes except cubes. This can be a value from 0 to 360 degrees.

Section Radius

Defines the thickness of the solid portion of the torus, relative to the radius of the torus’s central ring. The radius of the central ring is determined by the field’s scale. If you scale the field, the Section Radius will maintain its proportion relative to the central ring.

Special Effects

Available in the Attribute Editor for object fields only.

Apply Per Vertex

Sets where the field emanates from the object. If you turn on Apply Per Vertex, each individual point (CV, particle, vertex) of the chosen object exerts the field equally at full strength. If you turn off Apply Per Vertex, the field is exerted only from the average position of the specified points.

If you are using the Attribute Editor, open the Special Effects section to display the Apply Per Vertex attribute.