Sorry, I thought that there was a specific way (function) built in Unreal itself to convert the whole folder of assets (that can be converted of course, without proprietary formats ). But thank you for the idea. When I have a free time, I will look at the Google results about batch-converters.
Now, I’m learning C++ in Unreal because I will need it in my future project. It’s hard to find up to date tuts, but I found one Russian and it will the starting point for me. I can write programs with no problem because I have a long coding experience, but I noticed a few things:
1/ My HUD elements didn’t appear on the scene when I compiled the code. They appeared, when I restarted the UE4 and VS.
2/ Sometimes, the Build button from the Main Menu of UE4 disappears. The Visual Studio Solution User Options file in the folder of my project becomes greyish. I know that I should delete this file and Microsoft Visual Studio Solution file and then generate Visual Studio files again by right click on the Unreal Engine Project file.
3/ Sometimes, the are some dll linking problems that I see in the Output window of VS. I compile again and all great.
4/ My C++ classes don’t appear in the Class Viewer (to make blueprints from them)