<title>phys_hinge</title> # phys_hinge A physically simulated hinge that restricts the rotation of its attached entities to a given axis. Use the helper to define the axis of rotation. In code, it is defined in `HingeConstraint.cs` file under `addons\base\code\Entity\Hammer\Constraints`. In code, it is defined in the `HingeConstraint.cs` file under `addons\base\code\Entity\Hammer\Constraints`. ## Keyvalues **Name (`targetname`)** >* The name that other entities refer to this entity by. **Tags (`tags`)** >* A list of general purpose tags for this entity, for interactions with other entities such as triggers. **Friction (`friction`)** >* Resistance/friction in the constraint. **Min Rotation Limit (`min_rotation`)** >* Minimum rotation limit around hinge axis. **Max Rotation Limit (`max_rotation`)** >* Maximum rotation limit around hinge axis. **Initial rotation (`initial_rotation`)** >* Initial rotation of the hinge (values -1 to 1 where -1 mean open at minimum limit and 1 means open at maximum limit) **Hinge Axis (`hingeaxis`)** **Motor Frequency (`motorfrequency`)** >* Range 0 - 30 (only used when driving the relative angle through the angle input) **Motor damping ratio (`motordampingratio`)** >* Range 0 - 1 (only used when driving the relative angle through the angle input) **Entity 1 (`attach1`)** >* The source entity to constrain from. Leave empty to constrain from the world entity. **Entity 2 (`attach2`)** >* The entity we constrain to. **Enable Collision (`enablecollision`)** >* Constraints disable collision between the attached entities. In some rare cases we want to enable this collision. **Impulse Limit to Break (kg) (`forcelimit`)** >* The amount of impulse an impact must apply to the constraint to break it. A way of calculating this is to set it to the mass of an object that would break this constraint if it were resting on the constrainted objects. **Angular Impulse Limit to Break (kg* distance) (`torquelimit`)** >* The amount of angular impulse required to break the constraint. A way of calculating this is to multiply any reference mass by the resting distance (from the center of mass of the object) needed to break the constraint. **Play Sound on Break (`breaksound`)** >* A sound played when the constraint is broken.