Function createRaycastHit3D

createRaycastHit3D(): RaycastHit3D
Creates an empty RaycastHit3D, for View3D#raycast to fill again and again

target is unset until a raycast hits, so read it only after one returns the hit.

Returns RaycastHit3D
The new hit
Example
```
const hover = createRaycastHit3D();
app.ticker.add(() => {
  if (view3d.raycast(pointer, hover)) cursor3d.position.copyFrom(hover.point);
});
```