# Effects

> Visual effects: particle systems, hover text, texture animation, light and glow.

Effects are visual features rendered by the viewer from a few parameters set by a script. Once set, most of them keep running with no further script activity: the script describes the effect, it does not animate it frame by frame.

High quality effects often combine features: a technical mesh shape made in a modelling tool such as Blender, with an [animated texture](/functions/llSetTextureAnim/) and [glow](/constants/PRIM_GLOW/), can look like particles while costing far less.

## Concepts

- [Particle systems](/functions/llParticleSystem/)
  - A prim can emit one particle system, described by a list of rules for the emitter pattern, particle lifetime, size, color, speed, texture and flags
  - Combine flags with the bitwise OR operator (|)
  - An empty list stops the system; [another prim in the linkset](/functions/llLinkParticleSystem/) can be set too
- [Hover text](/functions/llSetText/)
  - Floating text above a prim, with a color and alpha
  - It is a [prim property](/constants/PRIM_TEXT/), so it stays when the script is removed
- [Texture animation](/functions/llSetTextureAnim/)
  - Plays frames from a grid on a texture, or scrolls, rotates or scales the texture, entirely in the viewer
  - Works [on any prim in the linkset](/functions/llSetLinkTextureAnim/)
- Light, glow and full bright
  - Prims can be [point lights](/constants/PRIM_POINT_LIGHT/) or [projectors](/constants/PRIM_PROJECTOR/)
  - Faces can [glow](/constants/PRIM_GLOW/) or [ignore lighting](/constants/PRIM_FULLBRIGHT/)
  - PBR materials add [emissive color](/constants/PRIM_GLTF_EMISSIVE/)
- Media and sound
  - Web pages on faces ([textures](/features/textures/)) and [sound](/features/sound/) round out many effects

## Functions and events

- `void` [`llParticleSystem`](/functions/llParticleSystem/) `(list rules)`
- `void` [`llLinkParticleSystem`](/functions/llLinkParticleSystem/) `(integer link, list rules)`
- `void` [`llSetText`](/functions/llSetText/) `(string text, vector color, float alpha)`
- `void` [`llSetTextureAnim`](/functions/llSetTextureAnim/) `(integer mode, integer face, integer sizex, integer sizey, float start, float length, float rate)`
- `void` [`llSetLinkTextureAnim`](/functions/llSetLinkTextureAnim/) `(integer link, integer mode, integer face, integer sizex, integer sizey, float start, float length, float rate)`
- `void` [`llSetLinkPrimitiveParamsFast`](/functions/llSetLinkPrimitiveParamsFast/) `(integer link, list rules)`

## [Particles](https://wiki.secondlife.com/wiki/Category:LSL_Particles)

Particle rules are `PSYS_*` constants: emitter (`PSYS_SRC_*`) and particle (`PSYS_PART_*`) settings. See the [reference below](#particle-rules).

## Technical mesh

A mesh shaped for the effect, with texture animation and glow, can replace many particles.

## Scripting Details

- `void` [`llParticleSystem`](/functions/llParticleSystem/) `(list rules)`: Creates or updates a particle system on the prim containing the script based on rules. An empty list removes the particle system.
- `void` [`llLinkParticleSystem`](/functions/llLinkParticleSystem/) `(integer link, list rules)`: Creates or updates a particle system on the linked prim link based on the list of rules. An empty list removes the particle system.
- `void` [`llSetText`](/functions/llSetText/) `(string text, vector color, float alpha)`: Displays floating text above the prim with the specified color vector and transparency alpha.
- `void` [`llSetTextureAnim`](/functions/llSetTextureAnim/) `(integer mode, integer face, integer sizex, integer sizey, float start, float length, float rate)`: Animates the texture on face of the prim by setting its scale and offset. mode defines options, sizex/sizey define frames, start defines the start frame/angle, length defines duration, and rate defines playback speed.
- `void` [`llSetLinkTextureAnim`](/functions/llSetLinkTextureAnim/) `(integer link, integer mode, integer face, integer sizex, integer sizey, float start, float length, float rate)`: Animates the texture on face of the linked prim link by setting the scale and offset according to mode. Parameters sizex/sizey define frames, start defines the start frame/angle, length defines duration, and rate defines playback speed.
- `void` [`llSetLinkPrimitiveParamsFast`](/functions/llSetLinkPrimitiveParamsFast/) `(integer link, list rules)`: Sets primitive parameters for the linked prim link according to rules with no built-in script sleep delay.

## Additional

- [`llParticleSystem`](/functions/llParticleSystem/) — the rules list
  - [`PSYS_PART_FLAGS`](/constants/PSYS_PART_FLAGS/) — bitfield of particle flags, combined with |
  - [`PSYS_PART_EMISSIVE_MASK`](/constants/PSYS_PART_EMISSIVE_MASK/) — particles are full-bright and unaffected by global lighting
  - [`PSYS_PART_RIBBON_MASK`](/constants/PSYS_PART_RIBBON_MASK/) — joins emitted particles into a continuous ribbon strip
  - [`PSYS_SRC_PATTERN`](/constants/PSYS_SRC_PATTERN/) — the generation pattern, such as [`PSYS_SRC_PATTERN_EXPLODE`](/constants/PSYS_SRC_PATTERN_EXPLODE/) (outward in all directions)
  - [`PSYS_SRC_TEXTURE`](/constants/PSYS_SRC_TEXTURE/) — inventory name or UUID of the particle texture
- [`llSetTextureAnim`](/functions/llSetTextureAnim/) — the mode flags
  - [`ANIM_ON`](/constants/ANIM_ON/) — must be set to start the animation and cleared to stop it
  - [`LOOP`](/constants/LOOP/) — loop continuously
  - [`SMOOTH`](/constants/SMOOTH/) — slide smoothly instead of instant frame changes
  - [`ROTATE`](/constants/ROTATE/) and [`SCALE`](/constants/SCALE/) — animate rotation or scale; they cannot be combined
- [`llSetLinkPrimitiveParamsFast`](/functions/llSetLinkPrimitiveParamsFast/) — light, glow and text as prim parameters
  - [`PRIM_POINT_LIGHT`](/constants/PRIM_POINT_LIGHT/) — local lighting; color in linear space (use [`llsRGB2Linear`](/functions/llsRGB2Linear/))
  - [`PRIM_PROJECTOR`](/constants/PRIM_PROJECTOR/) — texture, field of view, focus and ambiance of a light projection
  - [`PRIM_GLOW`](/constants/PRIM_GLOW/) — glow intensity on a face
  - [`PRIM_FULLBRIGHT`](/constants/PRIM_FULLBRIGHT/) — full-bright rendering on a face
  - [`PRIM_GLTF_EMISSIVE`](/constants/PRIM_GLTF_EMISSIVE/) — the GLTF emission override of a face
  - [`PRIM_TEXT`](/constants/PRIM_TEXT/) — hover text, equivalent to `llSetText`

## Particle rules

Constant groups: [ParticleParam](/constants/groups/ParticleParam/) (27), [ParticleFlag](/constants/groups/ParticleFlag/) (10), [ParticleSourcePattern](/constants/groups/ParticleSourcePattern/) (5), [ParticleBlendFunc](/constants/groups/ParticleBlendFunc/) (8)

## Texture animation modes

Constant groups: [TextureAnimMode](/constants/groups/TextureAnimMode/) (7)

## Related

See also: [Particles](/categories/particles/), [LSL Particles (Second Life Wiki)](https://wiki.secondlife.com/wiki/Category:LSL_Particles), [Script library: particles (Second Life Wiki)](https://wiki.secondlife.com/wiki/CatParticles)
   (planned: Recipe: particle effect presets)

See also: [LSL Floating Text (Second Life Wiki)](https://wiki.secondlife.com/wiki/Category:LSL_Floating_Text)

See also: [Textures & Materials](/features/textures/)
   (planned: Guide: technical mesh with texture animation)

See also: [LSL Light (Second Life Wiki)](https://wiki.secondlife.com/wiki/Category:LSL_Light), [Prims](/features/prims/)

See also: [Sound](/features/sound/), [Effects](/categories/effects/)

## Related features

- [Textures & Materials](/features/textures/)
- [Sound](/features/sound/)
- [Prims](/features/prims/)

## Categories

- [Particles](/categories/particles/)
- [Effects](/categories/effects/)

## On the Second Life Wiki

- [LSL Effects](https://wiki.secondlife.com/wiki/Category:LSL_Effects)

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From lsl.dev: https://lsl.dev/features/effects/