# Collision Detection
For the Touch UI input to work, we need to add colliders to each element that the user needs to engage with.
## Rect Transform Collider
You can use any kind of collider for the collision detection, however we have created a Rect Transform Collider component that will aid in creating a [Box Collider](🔗) that will automatically resize to the extends of your UI elements.
A Rect Transform Collider component
# Avatar Touch Trigger
The Avatar Touch Trigger component's purpose is to communicate collisions to attached components by sending the same messages that a regular UI click would.
An Avatar Touch Trigger component
There are a number of options for filtering unwanted collisions and haptic feedback which are detailed below.
| Column Title | Description |
| Click Event | When to send the 'click' event |
| Ignore Backface Collision | Disallow colliders entering from the back face of the UI, based on the position and forwards vector of this object's [Transform](🔗) |
| Required Collider Name | Required [GameObject](🔗) name of the colliding object. Set to null/empty to bypass the check. When using the included [Avatar Prefabs](🔗) you may want to set this to "IndexFinger_END" to only process fingertip pressses. |
| Enable Haptics | If true, will send a haptic pulse on the pointer click event |
| Haptic Amplitude | Amplitude of the haptic pulse |
| Haptic Duration | Duration of the haptic pulse |