dynamicConstraintShape

This node contains settings to control dynamic constraints on nCloth and nParticle objects. These settings include constraint methods, connection settings, and strength settings.

Sometimes you may want to constrain parts of your clothing to your character so it doesn’t fall off. You can do this using constraints. For example, you can use constraints to make sure the pants of your character stay on, or to keep straps on a dress attached to the shoulders.

In addition, you can use constraints to pin clothing together or attach items such as buttons or pockets.

Enable: When on, activates the dynamic constraints. Enable is on by default.

You can use this attribute to activate and deactivate the dynamic constraint as necessary, without the constrained cloth snapping back to the start position if it is animated. This means that the constraint links are automatically reformed when the constraint is reactivated, and the Rest Length is automatically adjusted to the distance at the time the constraint is reactivated.

Dynamic Constraint Attributes

Constraint Method

Determines the type of links used for this dynamic constraint. Select one of the following from the drop-down list:

Weld: Links lock vertices together so that they cannot be stretched.
Spring: Links recover their original state when released after being compressed or stretched (default).
Rubber Band: Links recover their original state when released after being stretched, but do nothing when compressed.

Constraint Relation

Determines how constrained objects are related to one another and related to the dynamic constraint. Select one of the following from the drop-down list:

Object to Constraint: Relates the input components of constrained objects to the dynamic constraint node position. This means that constrained objects are affected by transform and positioning changes to the dynamic constraint (default).
Object to Object: Relates the constrained objects to one another, and ignores the dynamic constraints position and transformations.

Component Relation

Determines how component nodes (nClothShape nodes, nParticleShape nodes, or nRigidShape nodes) are related to one another. A component is a member of this dynamic constraint, each member represents a subset of elements for an object (a group of triangles, or points, for example). Select one of the following from the drop-down list:

All to First: Relates all components to the first component that belongs to this dynamic constraint (default).
All to All: Relates all components to all other components that belong to this dynamic constraint.
Chain: Relates components in series, with each component related to the next component that belongs to this dynamic constraint.

Display Connections: When on, displays dynamic constraint links in the scene view. Display Connections is on by default.

Connection Method

Determines the logic used when links for this dynamic constraint are generated. Select one of the following from the drop-down list:

Component Order: Generates links between components based on the order the elements are listed on the component’s node.
Within Max Distance: Generates links between any components that are within the Max Distance value (in world space) at the start frame. This results in multiple components linking to each other.
Nearest Pairs: Generates links between each element and the nearest other element. This results in just one link from one element to another element.

Max Distance: Specifies the maximum distance allowed between linked elements when the Connection Method is set to Within Max Distance. The default is 0.1.

Connection Update

Specifies when the connection method is evaluated for this dynamic constraint. Select one of the following from the drop-down list:

At Start: Evaluates the connection method at the start of simulation (default).
Per Frame: Evaluates the connection method every frame of simulation.

Connect Within Component: When on, allows links between Maya Nucleus objects and components. When off, allows only links between components. This attribute is off by default.
Connection Density: Specifies the concentration of links for this dynamic constraint based on the Max Distance value. This attribute is only available when the Connection Method is set to Within Max Distance.

A value of 1 maintains links, while a value of 0 results in no links. Values between 0-1 determine the probability of broken links. You can use the Connection Density Range settings to scale this attribute.

Connection Density Range

These settings effect the Connection Density attribute, and are only available when the Connection Method is set to Within Max Distance.

Use the Connection Density Range settings to scale the Connection Density attribute, by setting values, or using the graph.

Use the graph to visually adjust the connection density. The right side of the graph represents the links that are the same length as the Max Distance value. The left side of the graph represents the links that have no length (value of 0).

Selected Position: The active value on the X-axis of the graph.

When you move the position marker in the graph, this value is automatically adjusted to correspond.
Selected Value: The active value on the Y-axis of the ramp graph.

When you move the position marker in the graph, this value is automatically adjusted to correspond.

Interpolation

Controls the way values are calculated in the graph. Select one of the following from the drop-down list:

None: There is no interpolation; each value is a distinct step on the graph.
Linear: The values are interpolated linearly in space.
Smooth: The values are interpolated along a bell curve, so that each value on the graph dominates the region around it, then blends quickly to the next value.
Spline: Similar to Smooth, but Spline takes into account neighboring indices for a smoother effect.

Strength: Determines the overall power of this dynamic constraint. Typical values are between 0-200. The default value is 20.
Tangent Strength: Determines the resistance to motion in the local tangent direction. Values from 0 to infinity are valid. The default value is 10.
Glue Strength: Determines how resistant this dynamic constraint is to breaking. This value is relative to the overall scene or object scale.

A Glue Strength of 1 means that the constraint does not break. A Glue Strength of 0 means that the constraint breaks immediately, as though no constraint exists at all. The default value is 1.

Because links are formed at the start frame, once links are broken they do not reform, unless the Glue Strength attribute is animated back to 1.
Glue Strength Scale: Determines the sensitivity of the Glue Strength attribute for the overall scene scale. Glue Strength uses the world space distance of separation between links to determine the point at which a break occurs. This attribute scales the required separation distance. The default value is 1.
Bend: When on, determines whether edge to edge constraints can bend. Bend is off by default.
Bend Strength: Determines how resistant to bending an edge constraint is. The default value is 20.
Bend Break Angle: Determines the angle (in degrees) at which edge to edge constraints stop bending. The default value is 360.
Force: Specifies an attractive or repulsive force between constrained points. The default value is 0, which applies no force.

For constraints between components, the force diminishes with distance according to the Dropoff Distance value. For transform constraints, the force is applied between the points and the center of the transform constraint.

You can apply this attribute to specific nCloth components, not just the object, unlike standard Maya fields.

Rest Length Method

Specifies how the rest length is determined for this dynamic constraint. Select one of the following from the drop-down list:

From Start Distance: Sets the constraint distances to the distance at the start frame. If the Rest Length Scale value is set to 1, the constraints have no tension, initially.
Constant: Sets the constraint distance to always be the value specified by the Rest Length attribute.

Rest Length: Specifies the rest length for links in this dynamic constraint in world space. This attribute is only available when the Rest Length Method is set to Constant.
Rest Length Scale: Determines how the rest length is dynamically scaled from the length determined at the start frame. The default value is 1.
Motion Drag: Specifies the amount of force applied to each constrained object that attracts it to the motion of another object. A Motion Drag value of 1 means that all the constrained objects are locked and move together. A Motion Drag value of 0 means that all the constrained objects do not move together. The default value is 0.
Dropoff Distance: This is the world space distance that the Strength Dropoff ramp is mapped to.

Strength Dropoff

The Strength Dropoff settings allow you to control the strength of links based on the Dropoff Distance. The right side of the graph represents the maximum distance for the links. The left side of the graph represents the links that have no length (value of 0).

You can use the graph to visually adjust the Strength Dropoff.

Selected Position: The active value on the X-axis of the graph.

When you move the position marker in the graph, this value is automatically adjusted to correspond.
Selected Value: The active value on the Y-axis of the graph.

When you move the position marker in the graph, this value is automatically adjusted to correspond.

Interpolation

Controls the way values are calculated in the graph. Select one of the following from the drop-down list:

None: There is no interpolation; each value is a distinct step on the graph.
Linear: The values are interpolated linearly in space.
Smooth: The values are interpolated along a bell curve, so that each value on the graph dominates the region around it, then blends quickly to the next value.
Spline: Similar to Smooth, but Spline takes into account neighboring indices for a smoother effect.

Exclude Collisions: When on, only nCloth constraint collisions are computed for the faces, edges, or vertices that are members of the current constraint.
Damp: Determines how much energy from the constraint is suppressed to reduce the movement of constrained elements. The default is 0.
Local Collide: When on, allows surface constraints to collide with the local surface at the constraint point. This collision is typically calculated more quickly than standard surface collisions. Local Collide is on by default for Point to Surface and Slide on Surface constraints.
Collide Width Scale: When Local Collide is turned on, the dynamicConstraintShape node handles the collisions between the constrained points. This can augment or replace the normal collisions between the objects. Collide Width Scale specifies a scaling value for the total collision thickness of the constrained objects. By default Collide Width Scale is set 1, meaning the collide width used for these collisions is based on the Thickness (nCloth) and Radius (nParticle) attribute values of the colliding objects.
Friction: Determines how freely sliding surface constraints can move. When Friction is set to 1, the surface constraints are locked and cannot move. When Friction is set to 0, the surface constraints are free to slide without restriction. The default is 0.
Single Sided: When on, restricts a surface constraint (that can move) to always being on one side of the constrained surface. The side that a constraint stays on is determined at the start frame and then maintained throughout simulation. This prevents constraints from flipping and pushing in the opposite direction when the constrained surface moves.

For example, you can constrain nCloth to an open cylinder and use the Single Sided attribute to keep the cloth from sliding into the cylinder, and use it to keep the cloth on the outside of the cylinder.
Max Iterations: Specifies the maximum number of iterations per simulation step for this dynamic constraint. Iterations are the number of calculations occurring within a step. Accuracy increases with increased iterations, however, calculation time also increases. The default value is 500.
Min Iterations: Specifies the minimum solver iterations used to evaluate the dynamic constraint. Iterations are the number of calculations occurring within a simulation step. When the current dynamic constraint’s Strength is low, Min Iterations increases the quality of the integration of the dynamic constraint’s effects. Min Iterations also affects other Nucleus object attributes such as the effect of Stretch Resistance on nCloth objects.