Volumetric Rendering

Overview

Volumetric shaders create visible light beams and cones by rendering transparent meshes with sophisticated noise and gradient effects. These shaders are the most computationally intensive part of the VR Stage Lighting system and include multiple quality modes for performance optimization.

Shader Paths

DMX Control

VRSL/Standard Mover/Volumetric
VRSL/Wash Mover/Volumetric

AudioLink Control

VRSL/AudioLink/Standard Mover/Volumetric
VRSL/AudioLink/Wash Mover/Volumetric

Core Volumetric Properties

Quality Modes

_HQMode

bool

default:"false"

Enable high quality volumetric mode (experimental). Uses _NoiseTexHigh instead of _NoiseTex for better visual quality.

_PotatoMode

bool

default:"false"

Performance mode that disables noise sampling and extra texture reads. Significant performance boost at the cost of visual quality.

_UseDepthLight

bool

default:"true"

Requires depth light to function. When disabled, volumetric will render without depth fade.

Textures

_LightMainTex

texture

default:"white"

Main light texture for the volumetric cone. Typically a radial gradient.

_NoiseTex

texture

default:"white"

Standard quality noise texture for volumetric distortion.

_NoiseTexHigh

texture

default:"white"

High quality noise texture used when _HQMode is enabled.

Noise Configuration

_MAGIC_NOISE_ON_HIGH

bool

default:"true"

Enable high quality magic noise effect.

_MAGIC_NOISE_ON_MED

bool

default:"true"

Enable medium quality magic noise effect.

_2D_NOISE_ON

bool

default:"true"

Enable 2D noise texture sampling.

_NoisePower

float

default:"1"

Base noise strength/intensity.

_NoiseSeed

float

default:"0"

Random seed value for noise variation.

Magic Noise Settings

Magic noise creates dynamic, animated 3D noise patterns. Three quality presets are available:

High Quality Mode

_Noise2Stretch

float

default:"1"

Outside magic noise scale (high quality).

_Noise2StretchInside

float

default:"1"

Inside magic noise scale (high quality).

_Noise2X

float

default:"1"

Magic noise X axis scroll speed (high quality).

_Noise2Y

float

default:"1"

Magic noise Y axis scroll speed (high quality).

_Noise2Z

float

default:"1"

Magic noise Z axis scroll speed (high quality).

_Noise2Power

float

default:"1"

Magic noise strength (high quality).

Default Mode

_Noise2StretchDefault

float

default:"1"

Outside magic noise scale (default quality).

_Noise2StretchInsideDefault

float

default:"1"

Inside magic noise scale (default quality).

_Noise2XDefault

float

default:"1"

Magic noise X scroll (default quality).

_Noise2YDefault

float

default:"1"

Magic noise Y scroll (default quality).

_Noise2ZDefault

float

default:"1"

Magic noise Z scroll (default quality).

_Noise2PowerDefault

float

default:"1"

Magic noise strength (default quality).

Potato Mode

_Noise2StretchPotato

float

default:"1"

Outside magic noise scale (potato quality - typically unused).

_Noise2StretchInsidePotato

float

default:"1"

Inside magic noise scale (potato quality - typically unused).

_Noise2XPotato

float

default:"1"

Magic noise X scroll (potato quality).

_Noise2YPotato

float

default:"1"

Magic noise Y scroll (potato quality).

_Noise2ZPotato

float

default:"1"

Magic noise Z scroll (potato quality).

_Noise2PowerPotato

float

default:"1"

Magic noise strength (potato quality).

Intensity and Fade

_FixtureMaxIntensity

float

default:"1"

Maximum cone intensity. Higher values create brighter, more visible volumetric beams.

_FadeStrength

float

default:"1"

Edge fade strength. Controls how sharply the cone edges fade out.

_InnerFadeStrength

float

default:"0"

Inner fade strength. Creates a hollow cone effect when increased.

_InnerIntensityCurve

float

default:"1"

Curve for inner intensity falloff.

_DistFade

float

default:"0.1"

Distance-based fade. Cone fades at distance.

_FadeAmt

float

default:"0.1"

Depth blending amount. Controls soft particle intersection with geometry.

Blinding Effect

_BlindingStrength

float

default:"1"

Strength of the blinding/bloom effect when looking into the light.

_BlindingAngleMod

float

default:"1"

Angle modifier for blinding effect. Adjusts viewing angle sensitivity.

Gradient Controls

_GradientMod

float

default:"2.25"

Gradient modifier for solid beams (no GOBO).

_GradientModGOBO

float

default:"2.25"

Gradient modifier when GOBO is active.

GOBO Beam Splitting

Creates stripe effects in the volumetric cone for different GOBO patterns:

_GoboBeamSplitEnable

bool

default:"false"

Enable beam splitting for GOBOs 2-8.

_StripeSplit

float

default:"0"

Stripe split frequency for GOBO 2.

_StripeSplitStrength

float

default:"0"

Stripe split intensity for GOBO 2.

_StripeSplit2

float

default:"0"

Stripe split frequency for GOBO 3.

_StripeSplitStrength2

float

default:"0"

Stripe split intensity for GOBO 3.

_StripeSplit3

float

default:"0"

Stripe split frequency for GOBO 4.

_StripeSplitStrength3

float

default:"0"

Stripe split intensity for GOBO 4.

_StripeSplit4

float

default:"0"

Stripe split frequency for GOBO 5.

_StripeSplitStrength4

float

default:"0"

Stripe split intensity for GOBO 5.

_StripeSplit5

float

default:"0"

Stripe split frequency for GOBO 6.

_StripeSplitStrength5

float

default:"0"

Stripe split intensity for GOBO 6.

_StripeSplit6

float

default:"0"

Stripe split frequency for GOBO 7.

_StripeSplitStrength6

float

default:"0"

Stripe split intensity for GOBO 7.

_StripeSplit7

float

default:"0"

Stripe split frequency for GOBO 8.

_StripeSplitStrength7

float

default:"0"

Stripe split intensity for GOBO 8.

Animation

_PulseSpeed

float

default:"0"

Speed of intensity pulse animation.

Rendering Properties

_RenderMode

enum

default:"1"

Volumetric rendering mode:

0: HQTransparent - Best quality, most expensive
1: Transparent - Standard transparency
2: AlphaToCoverage - MSAA-based transparency

_BlendDst

enum

default:"1"

Destination blend mode. Typically set to One for additive blending.

_BlendOp

enum

default:"0"

Blend operation.

_ZWrite

bool

default:"false"

Depth buffer writing. Always false for volumetrics.

_AlphaToCoverage

bool

default:"false"

Enable alpha to coverage mode.

Performance Optimization

Quality Levels

High Quality - Best visuals, lowest performance:

_HQMode = true
_PotatoMode = false
_MAGIC_NOISE_ON_HIGH = true
_MAGIC_NOISE_ON_MED = true
_2D_NOISE_ON = true

Standard Quality - Balanced:

_HQMode = false
_PotatoMode = false
_MAGIC_NOISE_ON_HIGH = false
_MAGIC_NOISE_ON_MED = true
_2D_NOISE_ON = true

Performance Mode - Best performance:

_HQMode = false
_PotatoMode = true
_MAGIC_NOISE_ON_HIGH = false
_MAGIC_NOISE_ON_MED = false
_2D_NOISE_ON = false

Shader Variants

The volumetric shader compiles multiple variants:

_MAGIC_NOISE_ON_HIGH - High quality noise
_MAGIC_NOISE_ON_MED - Medium quality noise
_USE_DEPTH_LIGHT - Depth-based effects
_POTATO_MODE_ON - Performance mode
_HQ_MODE - High quality mode
_2D_NOISE_ON - 2D noise sampling
_ALPHATEST_ON - Alpha testing

Total possible combinations: 128 variants

Optimization Tips

Reduce Cone Length: Shorter cones have less overdraw
- Use _ConeLength and _MaxConeLength conservatively
Simplify Noise: Disable unused noise features
- Turn off _MAGIC_NOISE_ON_HIGH if not needed
- Use _PotatoMode on low-end hardware
Limit Fixture Count: Volumetrics are expensive
- Consider using fewer fixtures with higher intensity
- Disable volumetrics for background/ambient lights
Adjust Fade Settings: Reduce visibility distance
- Lower _DistFade for shorter render distance
- Increase _FadeStrength for sharper edges (less translucency layers)
Use Lower Resolution: If using render textures
- Render volumetrics to lower resolution RT
- Upscale for final composite

Technical Details

Vertex Shader Calculations

The vertex shader pre-calculates:

Blinding effect based on view angle
Camera angle and fade
Stripe/split information
Cone width
World direction for depth correction
Intensity, strobe, GOBO selection, and spin speed
RGB color values

Fragment Shader Operations

The fragment shader performs:

Multi-layer noise sampling (2D + 3D magic noise)
Depth texture reading for soft particles
UV-based gradient calculations
GOBO stripe splitting
Edge fade calculations
Color blending and saturation
Mirror depth correction

Performance Characteristics

Vertex Shader: Lightweight

Simple position transforms
Minimal branching
Instanced property access

Fragment Shader: Heavy

Up to 3 texture samples per pixel (in HQ mode):
- _LightMainTex
- _NoiseTex or _NoiseTexHigh
- _CameraDepthTexture
Complex noise calculations
Distance-based fade calculations
High overdraw on large cones

Depth Fade Implementation

Soft particle intersection uses depth comparison:

float sceneZ = LinearEyeDepth(SAMPLE_DEPTH_TEXTURE_PROJ(
    _CameraDepthTexture, UNITY_PROJ_COORD(i.screenPos)));
float partZ = i.screenPos.z;
float fade = saturate((sceneZ - partZ) / _FadeAmt);

This creates smooth transitions where volumetric cones intersect geometry.

AudioLink Specific

_RenderTextureMultiplier

float

default:"1"

Multiplier for render texture intensity when using AudioLink.

_UseTraditionalSampling

bool

default:"false"

Use traditional texture sampling instead of AudioLink-specific sampling.

_IntersectionMod

float

default:"1"

Intersection modification for AudioLink mode.

Scripts

Shaders

Editor Tools

Overview

Shader Paths

DMX Control

AudioLink Control

Core Volumetric Properties

Quality Modes

Textures

Noise Configuration

Magic Noise Settings

High Quality Mode

Default Mode

Potato Mode

Intensity and Fade

Blinding Effect

Gradient Controls

GOBO Beam Splitting

Animation

Rendering Properties

Performance Optimization

Quality Levels

Shader Variants

Optimization Tips

Technical Details

Vertex Shader Calculations

Fragment Shader Operations

Performance Characteristics

Depth Fade Implementation

AudioLink Specific

See Also

Build docs developers (and LLMs) love

Scripts

Shaders

Editor Tools

​Overview

​Shader Paths

​DMX Control

​AudioLink Control

​Core Volumetric Properties

​Quality Modes

​Textures

​Noise Configuration

​Magic Noise Settings

​High Quality Mode

​Default Mode

​Potato Mode

​Intensity and Fade

​Blinding Effect

​Gradient Controls

​GOBO Beam Splitting

​Animation

​Rendering Properties

​Performance Optimization

​Quality Levels

​Shader Variants

​Optimization Tips

​Technical Details

​Vertex Shader Calculations

​Fragment Shader Operations

​Performance Characteristics

​Depth Fade Implementation

​AudioLink Specific

​See Also

Build docs developers (and LLMs) love

Overview

Shader Paths

DMX Control

AudioLink Control

Core Volumetric Properties

Quality Modes

Textures

Noise Configuration

Magic Noise Settings

High Quality Mode

Default Mode

Potato Mode

Intensity and Fade

Blinding Effect

Gradient Controls

GOBO Beam Splitting

Animation

Rendering Properties

Performance Optimization

Quality Levels

Shader Variants

Optimization Tips

Technical Details

Vertex Shader Calculations

Fragment Shader Operations

Performance Characteristics

Depth Fade Implementation

AudioLink Specific

See Also