How to make a load bar when change scene

when change scene,i need a load bar ui,change from 0% to 100%.
how to do this?
i create a load bar and change it manully.
but change scene will finish in one frame and this ui will not work!
how to do this

Hello,

Perhaps to help get you going, there have been a number of forum threads (loading screen), some things in https://github.com/urho3d/Urho3D/wiki (Background loading) and a working recent example in https://github.com/ArnisLielturks/Urho3D-Empty-Project

im creating scene by code…not by load from file/xml/json.
every element in my scene was created by c++ code.
the load bar will add 0.1% when each element was created!
how to do this async?

I think those approaches should be relevant if using the usual Create*, Scene::LoadAsync(), Scene::LoadAsyncXML(), if I understand what you mean.

My C++ state manager is inspired by a nice Urho-flavored one by OvermindDL1. A State subclass can handle incremental scene creation while displaying updates, for example.