# ScreenEffectsHandle

> Talos next · Since next

The params of the scene's `kind: post` screen effects (`meta.render.screenEffects`), set from a behaviour: a rain streak's strength, a vignette's radius.

See docs/SHADERS.md.

## Signature

```ts
export interface ScreenEffectsHandle {
  /**
   * Sets one param of a screen effect over the value the scene gives it, from the next frame until
   * the world restarts (a hot reload keeps it). `effect` is the effect's shader as
   * `meta.render.screenEffects` writes it (every entry running that file), or its index in that
   * list; `value` is what its `//! param` line declares, as {@link RenderHandle.setMaterialParam}
   * takes it. A buffer write, no rebuild: cheap every tick. An effect or param the scene does not
   * have, or a value of the wrong type, is one `screen-effects.param-refused` warning. Throws
   * `screen-effects.param-invalid` for an `effect` that is neither (a `TypeError`) or a number that
   * is not finite (a `RangeError`).
   */
  setParam(effect: string | number, param: string, value: ShaderParamValue): void
}
```

Import: `import type { ScreenEffectsHandle } from "@argus/api"`

## Members

| Member | Signature | Description |
|---|---|---|
| `setParam` | `setParam(effect: string \| number, param: string, value: ShaderParamValue): void` | Sets one param of a screen effect over the value the scene gives it, from the next frame until the world restarts (a hot reload keeps it). `effect` is the effect's shader as `meta.render.screenEffects` writes it (every entry running that file), or its index in that list; `value` is what its `//! param` line declares, as {@link RenderHandle.setMaterialParam} takes it. A buffer write, no rebuild: cheap every tick. An effect or param the scene does not have, or a value of the wrong type, is one `screen-effects.param-refused` warning. Throws `screen-effects.param-invalid` for an `effect` that is neither (a `TypeError`) or a number that is not finite (a `RangeError`). |