---
title: "Conditional: smoke"
description: Soft particles rise from an element while a condition is true.
---

Smoke puffs soft, rising particles from the top of the element. Use it for a hot or busy state, such as a device that is overheating or a task that is cooking.

## Usage

The sample lets smoke rise from a pot while it is on the stove.

```kotlin
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.shape.RoundedCornerShape
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.unit.dp
import com.jantursky.kapow.ConditionalEffect
import com.jantursky.kapow.conditionalEffect

@Composable
fun Pot(onStove: Boolean) {
    Box(
        Modifier
            .size(80.dp)
            .background(Color.DarkGray, RoundedCornerShape(12.dp))
            .conditionalEffect(onStove, ConditionalEffect.smoke(color = Color(0xFFC2C2C2))),
    )
}
```

## Parameters

| Parameter | Default | Description |
| --- | --- | --- |
| `color` | `Color(0xFF8A8A8A)` | Color of the smoke. |
| `rate` | `1f` | How often puffs come, as a factor: 2 is twice as many. Must be positive. |
| `size` | `10.dp` | Radius of a puff at its start. Must be positive. |
| `opacity` | `0.7f` | How opaque a puff gets at most, above 0 and up to 1. |
| `wind` | `0f` | A sideways push in dp per second squared. Positive blows to the right. |
| `physics` | `ParticlePhysics.Default` | How the particles launch and move: cone, speed, lifetime, gravity, drag, size, spin, fade, start and end scale and emission area. Parts left out keep the effect's own values; blend mode and color pick are ignored. `EmissionArea.Edge(...)` moves the source to another edge. |
| `seed` | `0` | The start of the random numbers that place and shape the puffs. The same seed gives the same smoke. |

## Reduced motion

No particles are emitted.

## Notes

- Particles draw through a [particle layer](/guides/particle-layer) when one is above the element, so a clipping parent does not cut them off. Without one they draw around the element.
- Particles come out of the top of the element continuously while the condition is true.
- When the condition turns false, no new particles start and the ones in flight finish their life.
- Particles do not follow the element if it moves.

## Live example

<iframe class="live-example" src="https://kapow-demo.vercel.app/#conditional-smoke" title="Live example: conditional-smoke" loading="lazy" allow="autoplay"></iframe>