So, metal is what you had in mind? I'm using C++ to do graphic programming

The reason I(might)consider opengl is because I'm new to graphics programming. And as for portability, I care deeply because it's what I want.

What modern gpu do you suggest for first time graphic programmers?

I care deeply about portability. I haven't started my engine yet because I'm too much of a beginner to figure out the rendering api, and since I never started, I figured opengl will be first

Is this objective-c? That's my target language for the virtual joystick

OK cool so I use this shown here and the virtual joystick will pop-up on the screen without me having to add any more code?

So in other words, glTF is supported by the metal api regardless?

Looks awesome! But is it for swift or c++? This here seems like scenekit or spritekit