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Setup Guide — Pressure Plate Door

This guide covers two variants of a pressure plate door:

  • Closes on release — the door opens when the player steps on the plate and closes when they step off.
  • Stays open — the door opens when the player steps on the plate and stays open permanently; stepping off has no effect.

What you need before you start

  • A door prefab with a mesh and an Animator.
  • A pressure plate prefab — a flat floor tile with a mesh, an Animator and a Collider.

Prefab hierarchy

Door                      ← door root
├── DoorMesh              ← door geometry + Animator

PressurePlate             ← plate root (placed on a floor cell)
└── Model                 ← plate geometry + Animator

The plate and door are separate GameObjects. The plate holds a reference to the door target in its Targets list.

Step 1 — Set up the door Animator

Select DoorMesh and open its Animator Controller:

States
  Idle_Closed     ← default
  Opening
  Idle_Opened
  Closing

Triggers
  Open
  Close

Transitions:

  • Idle_Closed → Opening — trigger Open, no Exit Time, Transition Duration 0.
  • Opening → Idle_Opened — Exit Time on, Transition Duration 0.
  • Idle_Opened → Closing — trigger Close, no Exit Time, Transition Duration 0.
  • Closing → Idle_Closed — Exit Time on, Transition Duration 0.

Step 2 — Set up the plate Animator

Select the plate's Model child and open its Animator Controller:

States
  Idle_Up         ← default (plate unpressed)
  Idle_Down       ← plate pressed

Triggers
  Press
  Release

Transitions:

  • Idle_Up → Idle_Down — trigger Press, no Exit Time, Transition Duration 0.
  • Idle_Down → Idle_Up — trigger Release, no Exit Time, Transition Duration 0.

The plate snaps immediately between up and down — no separate press/release animations are required, though you can add them if you have them.

Step 3 — Add components to the door

Add EdgeBlockerMarker and TriggerOpenDoor to the Door root. The fields are the same for both variants:

Field Value
Blocker Id Unique ID, e.g. door_trap_01
Door Animator Drag the Animator from DoorMesh
Open Anim Trigger Open
Close Anim Trigger Close
Opened State Name Idle_Opened
Closed State Name Idle_Closed

The two variants differ only in Close On Release:

Variant Close On Release
Closes when stepped off ✅ Enabled
Stays open permanently ❌ Disabled

Leave Skip Close Guard disabled in both cases.

Step 4 — Add PressurePlate to the plate root

Select the PressurePlate root and add PressurePlate:

Field Description
Source Id Unique string, e.g. plate_trap_01. Required if you want the plate state saved.
React To Party ✅ Enabled — the plate responds to the player standing on it.
React To Enemies Optional. Enable if you want enemies walking onto the plate to also trigger it.
Latching Leave disabled. Latching means the plate stays activated even after the weight is removed — useful for one-way triggers, but not for this use case.
Required Weight Leave at 0 for standard presence-only detection. Set a positive value (kg) if you want the plate to require a certain weight of items dropped on it before it activates.
Plate Animator Drag the Animator from the Model child.
Press Anim Trigger Press
Release Anim Trigger Release
Targets Drag the TriggerOpenDoor component from the door root.

Interact From Adjacent Cell

PressurePlate is a floor trigger — it activates automatically when the player steps onto its cell. It does not use mouse clicks or the Interact From Adjacent Cell setting.

How the close guard works with pressure plates

When Close On Release is enabled and the player steps off the plate, the door does not close immediately. It first checks that neither the player nor any living enemy is standing in the doorway. If the doorway is occupied the door waits, polling every 0.1 seconds, and closes as soon as both cells are clear.

This means the player can step off the plate and stand in the doorway — the door stays open until they move through.

Variant: stays open permanently

With Close On Release disabled, TriggerOpenDoor ignores the Released event entirely. The door opens the first time the plate is stepped on and never closes again regardless of what happens to the plate.

If you want this door to be openable only once (no re-closing from any source), this is the correct setup. If you want the door to be closable via a lever elsewhere in the dungeon, wire a second TriggerOpenDoor target on that lever instead.

Step 5 — Export

In the Dungeon Generator, click Generate Unique IDs (all doors) then Build Grid (Export JSON).

Testing

Press Play. Walk onto the plate cell. The plate animates down and the door opens. For the closes on release variant, walk off the plate — the door waits for the doorway to clear, then closes. For the stays open variant, the door remains open regardless of where you stand.

If the plate activates but the door doesn't open, check that the TriggerOpenDoor component appears in the Targets list on PressurePlate and that TriggerOpenDoor.BlockerId matches EdgeBlockerMarker.blockerId.

Summary of components

GameObject Components
Door (root) EdgeBlockerMarker, TriggerOpenDoor
DoorMesh (child) Animator (Open/Close triggers, four states)
PressurePlate (root) PressurePlate
Model (child) Animator (Press/Release triggers, two states)

Dungeon Crawler Framework — Mantis3de