constraints.types.distance.DistanceConstraint

constraints.types.distance.DistanceConstraint(
    param1,
    param2,
    distance,
    *,
    weight=1.0,
)

Constraint that fixes the distance between two points/vectors.

This constraint enforces: ||p1 - p2|| = distance

Reduces DOF by 1 (one scalar equation).

Parameters

Name	Type	Description	Default
param1	Vector	First point/vector (Vector parameter)	required
param2	Vector	Second point/vector (Vector parameter)	required
distance	Scalar | float	Target distance (Scalar parameter or float)	required

Example

p1 = Vector([0, 0, 0], free=True, name='p1')
p2 = Vector([1, 0, 0], free=True, name='p2')
constraint = DistanceConstraint(p1, p2, 0.2)

Methods

Name	Description
compute_residual	Compute distance constraint residual: ||p1 - p2|| - d.
dof_reduction	Distance constraint adds 1 scalar equation, reducing DOF by 1.
get_parameters	Return both parameters involved in the distance constraint.

compute_residual

constraints.types.distance.DistanceConstraint.compute_residual(param_values)

Compute distance constraint residual: ||p1 - p2|| - d.

Parameters

Name	Type	Description	Default
param_values	dict[str, Array]	Dict with keys matching parameter names	required

Returns

Name	Type	Description
	Array	Scalar residual (0 when constraint is satisfied)

dof_reduction

constraints.types.distance.DistanceConstraint.dof_reduction()

Distance constraint adds 1 scalar equation, reducing DOF by 1.

get_parameters

constraints.types.distance.DistanceConstraint.get_parameters()

Return both parameters involved in the distance constraint.