Six-way smoke lit reference

Learn about the available properties to configure smoke rendering.

These properties let you adjust lighting, animation, color, and performance.

The Smoke Shader UI contains the following properties:

Lightmap Remapping

The Lightmap Remapping section contains the following properties:

Property Description
Lightmap Remap Mode (dropdown) Select how to remap lightmap values for the smoke. The following options are available:
  • None: Map lightmap values directly, with no remapping.
  • Parametric Contrast: Adjust lightmap contrast using parameter controls to boost or soften lighting transitions.
  • Custom Curve: Define a custom remap curve for precise control over lighting effects on the smoke.
Lightmap Remap Range Set the input/output range for lightmap remapping, clamping or stretching light values as needed.
Use Alpha Remap Enable remapping of alpha values based on lighting to control transparency dynamically.

Emissive

The Emissive section contains the following properties:

Property Description
Emissive Mode (dropdown) Choose how the smoke emits light. The following options are available:
  • None: Disable emissive contribution, so smoke is only lit by external lights.
  • Single Channel: Use one channel to define emissive intensity, typically as a grayscale value.
  • Map: Apply a texture map to control emissive values for spatially varying glow.

Color and Alpha

The Color and Alpha section contains the following properties:

Property Description
Use Color Absorption Enable simulation of color absorption to let smoke filter and tint passing light.
Receive Shadows Allow smoke to receive shadows from other objects for added realism.
Enable Cookie Apply light cookies (patterned masks) to affect light interaction with the smoke.
Color Mode (dropdown) Control how color data is interpreted for rendering. The following options are available:
  • None: Use base color directly with no color processing.
  • Everything: Apply color processing to all channels.
  • Base Color: Process only the base color channel.
  • Emissive: Process only the emissive channel.
  • Base Color And Emissive: Process both base color and emissive channels.
Use Base Color Map Enable a texture map for base color to allow detailed color variation within the smoke.
Base Color Map Mode (dropdown) Select which channels to use from the base color map. The following options are available:
  • None: Apply no base color map.
  • Everything: Use all color channels from the base color map.
  • Color: Use only color channels (RGB) from the map.
  • Alpha: Use only the alpha channel from the map for transparency.
  • Color And Alpha: Use both color and alpha channels from the map.

Texture and UV

The Texture and UV section contains the following properties:

Property Description
Uv Mode (dropdown) Specify how UV coordinates are generated or used. The following options are available:
  • Default: Apply standard UV mapping for the texture.
  • Flipbook: Use flipbook animation for texture UVs, ideal for animated smoke sequences.
  • Scale And Bias: Scale and offset UVs for texture manipulation.
Flipbook Layout (dropdown) Define the layout of flipbook frames for animated textures. The following options are available:
  • Texture 2D: Use a standard 2D texture for smoke rendering.
  • Texture 2D Array: Use an array of 2D textures for complex animations or variations.
Base Color Set the base color for the smoke, as a constant or via a texture.
Flipbook Specify the flipbook asset or parameters for animated texture sequences.
Flipbook Blend Frames Control blending between flipbook frames for smooth animation.

Particle Rendering

The Particle Rendering section contains the following properties:

Property Description
Use Soft Particle Enable soft particle rendering to fade smoke edges near intersecting geometry for seamless integration.
Sort (dropdown) Control particle sorting for correct transparency rendering. The following options are available:
  • Auto: Automatically determine the best sorting mode.
  • Off: Disable sorting, which might cause visual artifacts in transparency.
  • On: Enable sorting for correct draw order.
Sort Mode (dropdown) Specify sorting algorithm for particles. The following options are available:
  • Distance To Camera: Sort by distance to the camera, common for transparency.
  • Youngest In Front: Sort by particle age, with newest particles in front.
  • Camera Depth: Sort by camera depth buffer.
  • Custom: Use a custom sorting function.
Revert Sorting Reverse the sorting order when needed.
Compute Culling Enable GPU culling of particles outside the view frustum for performance.
Frustum Culling Cull smoke particles outside the camera frustum to optimize rendering.
Cast Shadows Enable smoke particles to cast shadows onto other geometry.

Render States

The Render States section contains the following properties:

Property Description
Render States Control advanced render state overrides for the smoke material.
Blend Mode (dropdown) Set how smoke blends with the background. The following options are available:
  • Additive: Add smoke color to the background, ideal for light or glow effects.
  • Alpha: Use standard alpha blending for semi-transparent smoke.
  • Alpha Premultiplied: Use premultiplied alpha for improved compositing.
  • Opaque: Render smoke as fully opaque, with no blending.
Cull Mode (dropdown) Determine which faces are rendered. The following options are available:
  • Default: Apply standard culling (usually back-face).
  • Front: Render only front faces.
  • Back: Render only back faces.
  • Off: Disable face culling to render all faces.
Z Write Mode (dropdown) Control writing to the depth buffer (Z). The following options are available:
  • Default: Apply standard Z write behavior.
  • Off: Disable Z write, useful for transparency.
  • On: Enable Z write when needed for certain effects.
Z Test Mode (dropdown) Set the depth test function for rendering order. The following options are available:
  • Default: Use the default depth test (usually Less).
  • Less: Pass if incoming depth is less than stored.
  • Greater: Pass if incoming depth is greater than stored.
  • L Equal: Pass if less than or equal to stored.
  • G Equal: Pass if greater than or equal to stored.
  • Equal: Pass if depths are equal to stored.
  • Not Equal: Pass if depths are not equal to stored.
  • Always: Always pass, with no depth test.

Alpha and Motion

The Alpha and Motion section contains the following properties:

Property Description
Alpha Set a global alpha value for smoke to control overall transparency.
Use Alpha Clipping Enable alpha clipping to discard pixels below a certain alpha threshold for hard edges.
Generate Motion Vector Enable motion vector output for the smoke to support motion blur.
Exclude From TU And A Exclude smoke from certain rendering passes, such as temporal upscaling or anti-aliasing.
Sorting Priority Set render queue priority to control draw order relative to other transparent objects.