Eonevolve Learning
Unity and DevelopmentUnity and codeIntermediate~6 min

Rigidbody vs Collider vs Trigger: Who Owns the Bump?

Snapshot

~75 sec

Three components share ownership of a physical bump: a Rigidbody owns motion and mass, a Collider owns shape, and marking that collider Is Trigger decides whether it blocks movement or just reports overlap. Mixing up who owns what produces the classic "objects pass through each other" or "nothing detects the overlap" bugs.

You will learn

  • Separate what a Rigidbody owns from what a Collider owns.
  • Explain the difference between a solid collision and a trigger overlap.
  • Choose Is Trigger correctly for an invented pickup versus an invented wall.

Target outcome

You can decide, before writing any script, whether a bump should physically stop an object or only report that it happened.

Visual walkthrough

Visual walkthrough

~6 min

  1. Three owners, three jobs

    • Rigidbody

      Owns mass, velocity, and whether physics moves the object at all.

    • Collider

      Owns the shape used to detect overlap with other colliders.

    • Is Trigger

      A flag on a Collider: off means it physically blocks, on means it only reports overlap without blocking.

  2. Solid collision compared with a trigger

    ApproachBlocks movementScript callbackGood fit for
    Collider, Is Trigger offA wall, floor, or crate that should physically stop things.Yes - physics resolves the overlap and pushes objects apart.OnCollisionEnter / OnCollisionStay / OnCollisionExit.Ground, walls, solid obstacles.
    Collider, Is Trigger onA coin, a checkpoint, or a damage zone that should only be noticed.No - objects pass through freely.OnTriggerEnter / OnTriggerStay / OnTriggerExit.Pickups, zones, invisible sensors.

  5. Diagnose a pass-through bug

    An invented coin should disappear when the player touches it, but the player's capsule stops dead against the coin instead of collecting it. What is the single most likely cause?

    Expected reasoning

    The coin's collider is not marked Is Trigger. With it off, physics treats the coin as a solid obstacle and blocks the player instead of raising OnTriggerEnter. Turning Is Trigger on lets the player pass through while still firing the overlap callback the pickup script listens for.

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