2.4 KiB
Interaction System
The app currently supports 3 different types of interaction techniques:
- Using controllers with raycast
- Using hands with raycast
- Using hands with direct touch
The interaction system, like the Event System, is heavily inspired by the interaction system in browsers. Interaction Events can be broken down into 2 categories, Pointer Events initiated by a raycast and Touch Events initiated by a collision shape in the tip of the fingers. Pointer Events](/reference/EventPointer.html)
Pointer Events
When pressing the trigger button on the back of a controller or doing a pinch gesture with thumb and index finer an on_press_down event is triggered containing a EventPointer which holds information about the ray and initiator of the event. If the trigger button or pinch gesture is released before 400ms pass, an on_press_up and on_click event is triggered. If the trigger button or pinch gesture is held for more than 400ms, an on_press_move event is triggered each physics process and when releasing, only the on_press_up event is triggered.
The same logic can be applied to grab (on_grab_down, on_grab_move and on_grab_up) events, here the event family is triggered by the grip button on the controller or by doing a pinch gesture with thumb and middle finger.
Pinch Gesture
The pinch gesture is implemented by checking the distance between the thumb and each finger and if the distance is smaller than 3cm, the pinch gesture is detected.
Touch Events
Touch events are triggered when the collision shape present in the tip of the fingers enters another collision area. The on_touch_enter event is triggered when the collision shape enters the area, the on_touch_move event is triggered each physics process while the collision shape is inside the area and the on_touch_leave event is triggered when the collision shape leaves the area.
Hover (ray) Events
Each frame the ray is casted from the controller or hand and in case that the ray collides with a collision node, the on_ray_enter event is triggered. If the ray was already colliding with another object the previous frame, the on_ray_leave event is triggered on the old node.