Particle Light

The Particle Light node adds a light source to particles within a Particle System. Without any Light node, particles are rendered with flat color only (ambient lighting). Adding one or more Light nodes activates half-Lambert diffuse shading on particles, creating a sense of depth and dimensionality. The node supports three light types: Directional, Point, and Spot, along with configurable shadow casting.

Place the Light node inside a Particle System group. Up to 8 lights can be active simultaneously in a single system.

0 — Directional

Infinite parallel light rays coming from a single direction, like sunlight. All particles receive light from the same angle regardless of their position.

Key parameters: Direction (X/Y/Z), Color, Intensity

The Direction vector is automatically normalized. If all components are 0, it falls back to (0, -1, 0) (downward). Position has no effect on Directional lights.

1 — Point

Omnidirectional light radiating from a single point in space, like a light bulb. Light attenuates with distance up to the Range limit.

Key parameters: Position (X/Y/Z), Range, Color, Intensity

Point lights are useful for localized illumination effects. Place them near particle clusters for dramatic, proximity-based lighting.

2 — Spot

Cone-shaped light emitting from a point in a specific direction, like a flashlight or stage spotlight. Combines position, direction, range, and cone angle.

Key parameters: Position (X/Y/Z), Direction (X/Y/Z), Range, Spot Angle, Color, Intensity

The Spot Angle defines the inner cone where light is at full intensity. Beyond this angle (up to 1.2x the spot angle), light falls off to zero, creating a soft cone edge.

When Casts Shadows is enabled, the Particle System generates a shadow map from this light's perspective. The shadow pipeline consists of:

1. A depth-only render pass from the light's point of view.
2. During the main particle lighting pass, each particle samples the shadow map to determine if it is in shadow.
3. Shadow Strength controls how dark shadowed areas appear.
4. Shadow Softness applies blur to the shadow edges for smoother results.

Shadow Quality is shared across the system — the highest quality value from any shadow-casting light is used for the shadow map resolution.

• Single Directional light for even, predictable illumination (outdoor scenes)
• Point light at the center of an explosion for dramatic radial lighting
• Spot light for focused theatrical effects on particle streams
• Colored lights to tint particles without changing particle colors
• Multiple lights for complex lighting setups (key light + fill light + rim light)
• Shadow-casting lights for depth and realism in 3D particle scenes

• Particles must have Receive Light enabled in their Particle Type node to respond to lights. This is true by default for Billboard, Stretched, and Circle modes.
• One Directional light with Intensity 1 provides natural, even illumination. Start here and add more lights as needed.
• Point and Spot lights work best when positioned near particles. Large Range values with low Intensity create soft ambient fill.
• Shadow maps are expensive. Use sparingly — one shadow-casting directional light is often sufficient.
• Increase Shadow Bias if you see self-shadowing artifacts (speckled dark patches on particle surfaces).
• Use Show to visualize light positions and directions while setting up your lighting.
• For 3D particle types (Cube, Sphere), the PBR material system on the Particle Type node has its own built-in lighting. The Particle Light node provides system-level lighting that affects all particle types.