Not only P3D mode is using OpenGL, P2D is as well in Processing 2 series! Only JAVA2D is real 2D.
Seems like Processing is not recognizing your graphics 3D resources or something like that.
You should try to update your video card driver. Who knows?
In Linux, it's enough to rename or delete its /java subfolder to force Processing to use the OS's default Java.
Perhaps that works in OSX too.
As an experiment, you may try previous Processing's stable version 1.5.1.
In that version, even P3D mode uses software rendering.
Only by explicitly using OPENGL mode you get hardware rendering there.
Moreover, its OPENGL mode uses an old version of it.
It might be more compatible than the one from newest versions.
Seems like Processing is not recognizing your graphics 3D resources or something like that.
You should try to update your video card driver. Who knows?
Even though you have the most updated Java version installed, Processing uses instead its own old bundled Java!I'm running OSX 10.8.4, the most recent Java version 7 update 25, and Processing 2.0.1.
In Linux, it's enough to rename or delete its /java subfolder to force Processing to use the OS's default Java.
Perhaps that works in OSX too.
As an experiment, you may try previous Processing's stable version 1.5.1.
In that version, even P3D mode uses software rendering.
Only by explicitly using OPENGL mode you get hardware rendering there.
Moreover, its OPENGL mode uses an old version of it.
It might be more compatible than the one from newest versions.