Three.js ported to native code?

Here is a port of three to C++: https://github.com/jdduke/three_cpp

Core - 75% complete (TODO: Morph targets, shadows, plugin support)

Extras - 5-10% complete (TODO: Pretty much everything)

Examples - 25% complete (TODO: Examples involving morph targets an)

You're asking for a strict graphics engine only, in the same direction as OpenGL (in comparison to DirectX which again wants to be so much more than that). I'd advise Ogre3D for iPhone as the philosophy behind Ogre3d is to be a strict graphics engine.

The other one that comes to mind is recently perused MoSync mobile sdk which offers excellent OpenGL support across a wide range of platforms (albeit limited; to maintain portability).

If you're more interested in loading shaders and having the graphics engine manage the rest, I'd pick Ogre3D for iPhone.

You can always take the initiative (if you have the time of course) to write your own or start off from the ones mentioned here!

Or you can use a JavaScript engine (JSAPI for example) in a C++ editor and then move three.js on top of that. This is great as you'll only update the JSAPI and Three.js without breaking functionalities and your C++/JSThree engine will stay up to date with minimal maintenance.

Just some ideas of course!

Although I would also prefer to see a port of three.js for iOS, recently stumbled up on iSGL3d (http://isgl3d.com/).

This project serves a simple, encapsuled way to build an manipulate an opengl scene graph by code. Otherwise than some creative coding frameworks like cinder, iSGL3d comes in pure Objective C.

Works well for me yet.