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Approach & Press

Overview

Approach & Press is the core arrival behavior. Agents seek the target, and the front rank settles at a preferred standoff distance from the target body. The rear mass presses in behind them, with spacing emerging from Personal Space and body blocking rather than pre-assigned slots.

In motion this produces a tide of bodies that closes on the target, compresses against it, and holds there. Agents do not orbit or take turns. They push toward contact and the crowd equilibrium determines who actually reaches the front.

Use this for survivor-like crowds, zombie hordes, and any swarm that should chase and press against a target.

Two additional subgroups

The Approach & Press inspector block has two additional subgroups. The lost-target recovery fields live in Out-of-Sight Fallback under Lost Target Behavior. Combat Standoff, Chase Wander, and Chase Wander Interval are documented on this page, but you will not find them on the block itself: in Advanced mode they sit under Crowd Spread, in the Press & Wander group. Simple mode instead puts Combat Standoff directly on the approach block, which is titled Approach Target there. Approach & Press is the Advanced-mode title.

How it works

The diagram below shows what the pursuit fields on this page do. Each agent steers toward its standoff seek point, the nearest point on the standoff ring along its own radial to the target. The pull is scaled by Approach Weight and eases off as the agent comes within Arrival Distance of the ring.

Target Combat Standoff front rank settles on this ring Arrival Distance force eases near the ring standoff seek point nearest point on the ring Agent Approach Weight scales the pull toward the seek point
Top-down view. The Combat Standoff ring is where the front rank settles. Each agent steers toward its standoff seek point (the nearest point on that ring along its own radial to the target) with the pull scaled by Approach Weight and eased as it nears the ring (Arrival Distance).

Inspector at a glance

SwarmBehaviorProfile inspector showing the Approach & Press section: the section toggle, Approach Weight and Arrival Distance 1 2 3
1 Approach & Press toggle · 2 Approach Weight · 3 Arrival Distance

Runtime LOD note

The Approach & Press pass is throttled for agents outside the Full LOD tier. Reduced-tier agents recompute approach steering every Approach And Press Reduced Interval fixed steps; Cheap-tier agents recompute it every Approach And Press Cheap Interval fixed steps. The last computed steering is reapplied on skipped steps so chase pacing stays smooth.

When Use Out-of-Sight Fallback is on, agents farther from the target than Sight Distance switch to lost-target leader following instead of direct approach. With the toggle off (the default), an agent that can reach its target pursues it directly. Dormancy and surrender both ship on and both return before the approach seek runs, so a sleeping agent or one buried in a crush is not pursuing anything either way.

Parameter Reference

Simple Parameters

Start here: most projects only need these

  • Enabled

    The checkbox on the block header. On in a new profile, and on in every shipped preset.

    Details

    • Visible effect: Off, agents never seek a target. They still separate, wander and orbit, so they mill about rather than freeze.
    • Gameplay effect: Turn it off for ambient crowds that should not chase anything: pedestrians, wildlife, a milling mob in a hub area.
    • Increase when: Not applicable, it is a toggle.
    • Decrease when: Not applicable, it is a toggle.
    • Pitfalls: Disabling is not the same as setting Approach Weight to 0. The weight still leaves the pass running its bookkeeping; the toggle skips it entirely. Turn the toggle off when you want the saving. Also note that Out-of-Sight Fallback is a fallback for this behavior, so it goes inert with it.
    • Technical effect: Rated Medium performance impact in the inspector, because turning it on brings target assignment, visibility checks and optional lost-target neighbour following with it.

  • Approach Weight

    Controls how hard agents commit to closing on the target.

    Details

    • Visible effect: Higher values make agents drive harder toward the target. Lower values let other behaviors (Personal Space, Orbit Style) steer more.
    • Gameplay effect: More aggressive chase pressure versus more blending with spacing behaviors.
    • Increase when: Agents feel sluggish or separation is overpowering pursuit.
    • Decrease when: Agents shove through spacing or orbit behaviors too strongly.
    • Pitfalls: A weight of 0 is not the same as disabled. The behavior still runs internal bookkeeping. Very high values dominate blended steering before the manager clamps the final result.
    • Technical effect: Scales the unit steering vector toward the standoff seek point. Also scales the lost-target seek bias, but not the leader-follow weight.

  • Combat Standoff

    Sets how close the front rank presses against the target body before easing off.

    Details

    • Visible effect: Larger values keep the crowd a step outside the target body. Zero lets agents press against the body surface.
    • Gameplay effect: For melee archetypes, keep this at or near zero so agents reach attack range. Raise it for bosses or large targets that should not be mobbed into the chest.
    • Increase when: Agents clip visually into large targets, or the archetype should keep a visible gap before attacking.
    • Decrease when: Melee swarms should make tight contact.
    • Pitfalls: This is extra padding beyond the combined body radii, not a raw center distance. The target body radius comes from the SwarmTarget component, not this profile.
    • Technical effect: Inner standoff ring = targetBodyRadius + agentRadius + combatStandoff. The seek drives agent centers onto that ring, so front-rank bodies end up targetBodyRadius + combatStandoff from the target center. Attack reach is checked independently by the attack profile.

Advanced Parameters

Power-user knobs: leave at defaults unless you have a reason

Arrival Distance

  • Visible effect: Larger values create a softer stop before the standoff position. Smaller values make agents drive closer before easing off.
  • Gameplay effect: Larger values feel heavier and less jittery near the target; smaller values feel more direct.
  • Increase when: Agents overshoot, vibrate, or constantly micro-correct near the target.
  • Decrease when: Agents stop too early or leave too much space before the standoff.
  • Pitfalls: Setting this to 0 removes arrival easing entirely. Very large values can make the crowd feel soft and over-damped near the target.
  • Technical effect: Beyond this distance the approach force pulls at full weight. Inside it the force scales down with remaining distance (magnitude ≈ Weight × distance / Arrival Distance), fading to zero as the agent reaches the standoff point. Easing is measured from the standoff surface, not the target center. Past that point the radial reverses: an agent shoved inside the standoff ring is pushed back out, scaled by how deep it went rather than by this value.

Chase Wander

  • Visible effect: The crowd edge looks slightly ragged rather than a clean ring. Agents drift on small, slowly-shifting individual paths while chasing.
  • Gameplay effect: Breaks up the mathematical regularity of the approach so large crowds read as organic. Every agent gets the same magnitude, so where it reads strongest is a matter of how tightly that part of the crowd is packed: it shows up on the loose outer ranks and is squeezed out of the front rank by the bodies around it.
  • Increase when: A large crowd looks too geometrically clean.
  • Decrease when: You want crisp approach geometry, or the drift is pushing front-rank agents out of melee reach. 0 disables it entirely.
  • Pitfalls: High values can push front-rank agents beyond attack reach. It runs at full scale during direct chase and while an agent is following a live leader. The scale only decays once the leader is gone too and the agent is replaying its remembered direction.
  • Technical effect: Adds a planar wander vector scaled by ChaseWanderWeight * awareness each step. During direct chase awareness = 1; during lost-target following awareness = followScale. Direction lerps between two consecutive seeded vectors, changing every Chase Wander Interval seconds.

Chase Wander Interval

  • Visible effect: Low values make agents shift direction more often, producing busier-looking drift. High values produce longer, calmer drifts.
  • Gameplay effect: Faster intervals feel lively but slightly agitated. Slower intervals feel more natural.
  • Increase when: Direction changes look too rapid or noisy.
  • Decrease when: Agents drift in one direction too long and visibly pull away from the crowd.
  • Pitfalls: Has no visible effect when Chase Wander is 0. The runtime enforces a minimum of 0.05 seconds regardless of the inspector value.
  • Technical effect: Sets the time slice length for direction interpolation: floor(simulationTime / interval) selects the pair of seeded directions to lerp between. Each agent uses a unique seed, so direction changes are not synchronized across the crowd.

Practical Usage Guidance

Use this as the main arrival driver for survivor-like games, zombie hordes, and melee swarms. It pairs well with Personal Space for readable dense crowds. Agents queue automatically against the front rank, and there is no separate queue behavior to enable.

Predictive Catch-Up can be added for faster units. Give it to a few archetypes rather than the whole horde, or every enemy in the scene starts guessing where the player is going at once.

Avoid relying on this alone for strafing enemies or enemies that need a strict minimum distance. Pair lightly with Orbit Style for those, or lower the approach weight to give orbit room to steer.

Gameplay Interpretation

Strong approach weight and low combat standoff make enemies feel aggressive, because the crowd presses hard against the target body. Raising combat standoff pulls the front rank back off the body, which reads as a wary circle rather than a pile-on.

Adding small Chase Wander to a large crowd makes the approach edge look like a crowd rather than a formation. The effect is mostly invisible on small groups but clearly improves the read on 50+ agents.

Quickstart: tune in this order

  1. Enable the behavior and set Approach Weight until pursuit pressure feels right against the movement profile.
  2. Set Combat Standoff, usually 0 for tight melee; raise it only if agents need a gap before the target body.
  3. Adjust Arrival Distance only if agents overshoot or stop too early.
  4. Add Chase Wander if a large crowd edge looks too geometrically clean; adjust Chase Wander Interval to taste.
  5. Enable Out-of-Sight Fallback only if the game needs limited awareness or recovery behavior.