# Fill Iris (`.sds-btn-fill-iris`)

Tint blooms from the center as an iris while the button breathes 0.985→1 on a spring. Buttons animation in SDS Motion Forge v5.0.0. It loops continuously as soon as the class is applied.

- Page: https://sds-motion-forge.netlify.app/animations/btn-fill-iris/
- Category: Buttons (https://sds-motion-forge.netlify.app/categories/buttons/)
- Animated properties: clip-path, opacity, transform
- Compositor-only: yes
- Needs child elements: no
- Needs per-character spans: no
- JavaScript: none required

## Use it

```html
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@salkomdesignstudio/sds-motion-forge/dist/categories/buttons.min.css" />

<button class="sds-btn-fill-iris">Button</button>
```

## How it works

Plays as soon as the class is applied, looping continuously. It animates a clip-path mask, opacity and movement and scale (transform) — compositor-only, so it never causes page reflow. `--sds-duration-slower` controls the speed and `--sds-ease-decelerate` controls the feel — override either on the element or :root (the sds-fast/sds-slow modifier classes do exactly that).

## Related

- [Fill Corner](https://sds-motion-forge.netlify.app/animations/btn-fill-corner/)
- [Fill Drain](https://sds-motion-forge.netlify.app/animations/btn-fill-drain/)
- [Fill Rise](https://sds-motion-forge.netlify.app/animations/btn-fill-rise/)
- [Fill Split](https://sds-motion-forge.netlify.app/animations/btn-fill-split/)
- [Fill Sweep](https://sds-motion-forge.netlify.app/animations/btn-fill-sweep/)
- [Fill Wave](https://sds-motion-forge.netlify.app/animations/btn-fill-wave/)
- [Energy Ripple](https://sds-motion-forge.netlify.app/animations/btn-energy/)