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Transform Fast Projectile

Moves a projectile forward each physics step and reliably detects collisions without requiring a Rigidbody.

Designed for fast-moving objects like lasers, bullets, plasma bolts, spells, missiles, or anything that should hit the first object in its path without tunneling through.

The action sweeps between frames using a thin or thick collision check (raycast or spherecast) to ensure the projectile never passes through objects, even at very high speeds.

Parameters

Parameter Description
Transform The projectile Transform that will be moved forward each frame.
Speed How fast the projectile travels (units per second).
Direction The direction the projectile moves. If left empty, uses the Transform’s forward direction.
Space Mode Whether the Direction is interpreted in World or Local space.
Collision Radius Set to 0 for a thin raycast, or use a small radius to make the projectile more reliable (recommended).
Layer Mask Which layers the projectile can collide with.
Trigger Interaction Whether triggers should be detected by the sweep.
Hit Event Event sent when the projectile hits something.
Hit (Optional) Stores true/false if a hit occurred.
Hit Object (Optional) Stores the GameObject that was hit.
Hit Info (Optional) Stores a full RaycastHit with details (point, normal, distance, etc.).

⚙ Details

This action is ideal for projectiles that move in a straight line and should hit something immediately and accurately.

Key behaviors:

  • Moves the projectile every physics step
  • Checks the space between frames to ensure nothing is skipped
    (prevents tunneling through thin or fast-moving objects)
  • Supports ray-style hits (radius = 0) or bullet-style hits (sphere radius > 0)
  • Sends a hit event and stops running when something is struck
  • Works perfectly with pooled projectiles (no Rigidbody required)

When to use it

Use this action when you want:

  • Reliable laser-style projectiles
  • Fast-moving bullets that never miss due to physics tunneling
  • Projectiles that should stop at the first object they hit
  • Simple forward-moving effects with optional impact VFX

Performance

  • Update Mode: Runs in FixedUpdate, in sync with Unity physics
  • Performance Impact: Very low - performs one raycast or spherecast per frame
  • No Rigidbody required → avoids physics overhead entirely

Spherecasts with very large radii cost more than raycasts, so keep the radius small unless needed.

Debugging

Inspector Information:

  • Optional debug line shows the forward sweep each frame
  • Hit variables will populate only when a collision occurs

Common Issues:

  • If the projectile appears to pass through objects, increase Collision Radius
  • Ensure the hit layers include the objects you're testing against
  • If using Local direction, confirm the projectile’s rotation is correct at spawn
  • Extremely large Fixed Timestep values can reduce accuracy (default 0.02 is ideal)

Examples

Typical Gameplay Uses

  1. Space shooters
    • Laser bolts fire quickly and stop instantly when striking ships
  2. First-person weapons
    • Fast projectiles that behave like hit-scan but with visible travel
  3. Magic spells
    • Fireballs or bolts that fly straight and impact reliably
  4. Sci-fi projectiles
    • Plasma rounds, energy beams, and other VFX-based shots

Best Practices

  • Use Collision Radius > 0 for small or fast projectiles
  • Use Hit Object to apply damage or spawn impact effects
  • Use Hit Info for advanced reactions (impact direction, decals, sparks)
  • Combine with a visual component (quad, sprite, mesh, ribbon) for the projectile body
  • Pool projectiles for best performance in high-fire-rate weapons

Transform Fast Projectile is a lightweight and reliable way to handle fast-moving hits without the complexity of full physics simulation.