Houdini 19.5 Nodes Dynamics nodes

Agent Look At 3.0 dynamics node

Defines a target that an agent can turn its head to look at.

Since 19.5

This node is used together with Agent Look At Apply, which selects a target and adjusts the agent’s skeleton to look toward the target’s position. You should enable the Apply Look Ats parameter when you use the Crowd Solver.

You can chain several Agent Look At nodes together to define multiple targets. For more procedural setups, set Target Type to Points to allow each point in the specified geometry to be considered as a target.

Parameters

Group

The group of agents to modify.

Target Name

Specifies a unique name for this target.

You can use this with Crowd Trigger DOP to activate a trigger based on the agent’s current target.

Guide

Specifies whether to display the guide geometry for the look at targets.

Target Type

Specifies how to determine the target’s position.

Position

Uses the target position specified by the Position parameter.

Object

Computes the target position using the object’s transform specified by the Object path. If the object contains geometry, it also includes the centroid of the geometry.

Points

Can use each point in the specified geometry as a target. The standard instancing point attributes defines the target’s position, orientation, and velocity. You can also use the agentlookat_targetscore float point attribute to scale the Score Multiplier per point.

Agents

Can use each agent in the crowd as a target. You can also use The agentlookat_targetscore float point attribute to scale the Score Multiplier per agent.

Object

Specifies the path to an object or SOP geometry.

Position

A world-space position for the look at target.

Group

The group of points to look at.

Geometry Source

Specifies the geometry to use.

Use Parameter Values

Use the SOP specified in the SOP Path parameter.

Use DOP Object

Use the named DOP object in this DOP network.

Use First Context Geometry

Use the SOP connected to the DOP network’s first input.

Use Second Context Geometry

Use the SOP connected to the DOP network’s second input.

Use Third Context Geometry

Use the SOP connected to the DOP network’s third input.

Use Fourth Context Geometry

Use the SOP connected to the DOP network’s fourth input.

SOP Path

Path to the SOP (when Geometry Source is set to Use Parameter Values).

DOP Objects

Name of DOP Objects (When Geometry Source is set to Use DOP Object).

Max Search Points

The maximum number of nearby points to consider when selecting a point to look at.

Group

The group of agents to look at.

Max Neighbors

The maximum number of nearest neighbors to consider when selecting an agent to look at.

Match by Attribute

When the Target Type is Points or Agents, only considers points for which the Target Attribute matches the agent’s value for the Agent Attribute. This can be useful to precisely control which target(s) an agent can look at.

The attributes can be an integer or string type. For string attributes, the Agent Attribute can be a string pattern that is matched against the Target Attribute value. For integer attributes, if the Target Attribute is not specified the point number will be used instead.

Agent Attribute

The name of a string or integer point attribute on the crowd geometry.

Target Attribute

The name of a string or integer point attribute on the target geometry (when the Target Type is Agents, the target geometry is also the crowd geometry).

Target Visibility

Distance Range

Specifies the minimum and maximum distance for the target to be visible. When the Target Type is Points or Agents, the maximum distance limits the number of nearby points considered.

Horizontal FOV

The maximum horizontal angle (in degrees) at which the target is visible.

Horizontal FOV Mode

Specifies how the horizontal FOV is determined for each agent.

Horizontal FOV Attribute

Overrides or multiplies the Horizontal FOV with the value of a point attribute on the agent. If the value is overridden, the attribute value is in radians.

Vertical FOV

The maximum vertical angle (in degrees) at which the target is visible.

Vertical FOV Mode

Specifies how the vertical FOV is determined for each agent.

Vertical FOV Attribute

Overrides or multiplies the Vertical FOV with the value of a point attribute on the agent. If the value is overridden, the attribute value is in radians.

Target Score

Controls how interesting the target is to an agent, based on factors such distance, speed, or orientation. The scoring factors are normalized values (from 0 to 1), and the final score is computed as a weighted average. The Agent Look At Apply DOP selects the target with the highest score when an agent chooses a target to look at.

Distance Weight

The weight for the target’s distance score. Adjusts the importance of targets that are close to the agent. The distance score has a value of 1 at the minimum of the Distance Range, and a value of 0 at the maximum distance.

Periphery Weight

The weight for the target’s periphery score. Adjusts the importance of targets that are entering the edge of the field of view.

Relative Orientation Weight

The weight for the target’s orientation score. Adjusts the importance of targets that are facing towards the agent and are in the center of the field of view.

Relative Speed Weight

The weight for the target’s speed score, which is higher for targets that have a larger speed relative to the agent. Adjusts the importance of fast-moving targets. The speed score has a value of 0 at the minimum of the Relative Speed Range, and a value of 1 at the maximum speed.

Relative Speed Range

Specifies the minimum and maximum relative speeds, which determine the target’s relative speed score when the Relative Speed Weight is non-zero.

Score Multiplier

Scales the target’s overall score. You can manually adjust the importance of specific targets. When the Target Type is Points or Agents, this can be multiplied per point with the agentlookat_targetscore attribute.

Gaze Duration

Gaze Duration Time

Specifies the minimum and maximum time (in seconds) that the agent can look at this target for. This allows the agent to lose interest in a target over time. After the minimum duration the target’s score will gradually decrease, allowing the agent to switch to a target that has a higher score. After the maximum duration has elapsed, the agent will stop looking at the target.

Gaze Duration Mode

Specifies how the gaze duration is determined for each agent.

Gaze Duration Attribute

Overrides or multiplies the Gaze Duration Time with the value of a point attribute on the agent. If the value is overridden, the attribute has a tuple size of 2.

Random Time Offset

Randomly increases the minimum gaze duration. This allows agents to start losing interest in the target at different times.

Random Seed

Seed used when randomly varying the gaze duration time.

See also

Dynamics nodes