Rain VFX [HDRP, URP] Documentation for Unity

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Package Requirements

  1. Unity version 6+
  2. Project created using either High Definition Render Pipeline (HDRP) or Universal Render Pipeline (URP)
  3. VFX Graph 17.0.4+
  4. Input System (for smooth demo experience, not required for effects to work)

How to install

1. Open the Package Manager and install any required Visual Effect Graph dependencies if prompted.

2. Import the appropriate package for your render pipeline:

  • HDRP
  • URP

INCLUDED PREFABS

Character Follow Rain
The rain follows the player or camera.

 

Includes

  • Light Rain
  • Medium Rain
  • Heavy Rain

Features

  • Automatic camera detection
  • Character-follow rain volume
  • Raycast splash interaction
  • Collision presets
 World Rain
A static rain volume that can be placed anywhere in your scene.
 

Includes

  • Light Rain
  • Medium Rain
  • Heavy Rain

Features

  • Static rain area
  • Automatic splash sampling
  • Raycast surface interaction
  • Collision presets

How to use

Character Follow Rain
  1. Drag one of the Character Follow prefabs into the scene.
  2. Press Play.
  3. The rain automatically follows the Main Camera.
  4. Adjust the exposed parameters in the Inspector if needed.
World Rain
  1. Drag one of the World Rain prefabs into the scene.
  2. Position the prefab where the rain should appear.
  3. Adjust the exposed parameters in the Inspector.
  4. Press Play.

RAYCAST SPLASH SYSTEM

The package includes two raycast splash systems.

 

Character Follow

Creates splash events around the player for accurate surface interaction.

 

World Rain

Creates splash events throughout the rain volume for static environmental rain.

 

The splash area automatically matches the exposed Rain Particle Spawn Box Size parameter.

COLLISION OPTIONS

Three collision workflows are included.

Raycast Splash (Recommended)
  • Accurate
  • Works on arbitrary geometry
  • Recommended for gameplay
Depth Buffer Collision
  • GPU collision
  • Fast
  • Best suited for visible scene geometry
  • Can be used as a lightweight alternative
Plane Collision
  • Simple setup
  • Ideal for flat surfaces
  • Good for prototypes and stylized scenes
 

TROUBLESHOOTING

No rain is visible
  • Verify the correct render pipeline package was imported.
  • Check that the Visual Effect component is enabled.
No splashes appear
  • Ensure the correct Collision Layer Mask is assigned.
  • Verify colliders exist in the scene.
  • Check that the raycast rays are long enough to hit the surfaces.
  • Check that the splash Visual Effect is enabled.
Character Follow Rain does not move
  • Ensure the scene contains a camera tagged MainCamera.
  • Alternatively, assign the Target Camera manually.

SUPPORT

If you have questions or encounter any issues, feel free to contact me

info@paulinavfx.com

VFX Parameters

Parameter name Explanation
VFX Bounds Size Controls the size of the VFX system bounds used for visibility and culling calculations.
VFX Bounds Center Coordinates Controls the position of the VFX system bounds relative to the effect.
Rain Particle Camera Fade Distance [FADED, VISIBLE] Controls the distance range from the camera over which rain particles fade between invisible and fully visible.
Rain Particle Spawn Rate Controls the number of rain particles spawned per second.
Rain Particle Spawn Box Size Controls the dimensions of the volume where rain particles are spawned.
Rain Particle Size Controls the base size of the rain particles.
Rain Particle Scale Singular [MIN, MAX] [Random] Controls the random scale range applied uniformly to individual rain particles.
Rain Particle Scale [MIN, MAX] [Random] Controls the random scale range applied to the rain particles.
Rain Particle Lifetime [MIN, MAX] [Random] Controls the random lifetime range used before rain particles are removed.
Rain Particle Velocity [MIN] Controls the minimum velocity used for random rain particle movement.
Rain Particle Velocity [MAX] Controls the maximum velocity used for random rain particle movement.
Rain Particle Color Controls the color tint applied to rain particles.
Enable Depth Buffer Collision Controls whether rain particles collide with scene geometry using the camera depth buffer.
Enable Plane Collision Controls whether rain particles collide with a defined collision plane.
Plane Collision Position Controls the position of the plane used for rain particle collision.
Splash Particle Size Controls the base size of the splash particles.
Splash Particle Scale [MIN, MAX] [Random] Controls the random scale range applied to splash particles.
Splash Particle Lifetime [MIN, MAX] [Random] Controls the random lifetime range used before splash particles are removed.
Splash Particle Color Controls the color tint applied to splash particles.
Enable Mist Controls whether the mist particle system is enabled.
Mist Particle Spawn Rate Controls the number of mist particles spawned per second.
Mist Particle Spawn Box Size Controls the dimensions of the volume where mist particles are spawned.
Mist Particle Spawn Box Center Controls the position offset of the mist spawn volume.
Mist Particle Size Controls the base size of the mist particles.
Mist Particle Scale Controls the overall scale applied to mist particles.
Mist Particle Lifetime [MIN, MAX] [Random] Controls the random lifetime range used before mist particles are removed.
Mist Particle Velocity [MIN] [Random] Controls the minimum velocity used for random mist particle movement.
Mist Particle Velocity [MAX] [Random] Controls the maximum velocity used for random mist particle movement.
Mist Particle Color Controls the color tint applied to mist particles.
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