which API should I learn to develop a 3D reconstruction app on iOS?

I am a beginner for iOS.I decide to use swift language to develop an app about 3D reconstruction on my iPhone. I need to analysis some 2D images of my target then get and display the 3D image of my target. I hope someone has the experience of 3D reconstruction on iOS can tell me which API I should learn to develop this app. Main task: 2D Image analysis ,display the 3D image.