Houdini 16.5 Nodes Dynamics nodes

POP Steer Turn Constraint dynamics node

Constrains agent velocity to only go in a direction within a certain angle range of its current heading, to prevent agents from floating backward.

This node is used internally in the Crowd solver. It relies on the crowd system’s steerforce attribute, so unlike other "POP Steer" nodes it is not also useful for plain particles.

This node modifies agent/particle speed based on its orientation and target velocity direction. It will be scaled based on agent orientation/facing direction and velocity direction. Value of zero will result in speed unaffected, where at Max Angle the speed will be zero. Any values in between will be linearly scaled 0 to 1.



When this is off, the node will have no effect. You can animate this to turn the behavior on or off at different times.


The attribute to use as the agent/particle’s direction/velocity. The default "Velocity" uses the v attribute. Choose "Custom vector" if you want to use a custom attribute.

Custom Vector

When Use is "Custom vector", the name of the custom attribute to use.

Min Angle

Minimum angle between agent orientation and target velocity where speed is unaffected.

Max Angle

Maximum angle between agent orientation and target velocity where speed is zero.

Reference Direction

Orientation is calculated relative to this direction.

Reference Object

Custom object to be used for reference.

Use Up Vector

Use Up as the agent’s up vector.


An up vector to use when calculating the agent’s heading.

Reference Up:

Dynamics nodes