Unity3D: Rotate Object Around Y-Axis Using Mouse Drag

Vector3 cross = Vector3.Cross(new Vector3(eventData.delta.x, eventData.delta.y), Vector3.forward).normalized;
// Set the Y component of the cross vector to 0 to only rotate around the Y-axis
cross.y = 0f;
cross.Normalize();

// Use the modified cross vector to rotate around the Y-axis
if (_Model != null)
{
    _Model.transform.Rotate(cross, eventData.delta.magnitude * 0.3f, Space.World);
}

This modified code sets the Y component of the 'cross' vector to 0 before normalizing it. This ensures that the rotation only occurs around the Y-axis.