I meant 3d in the sense of modeling AND animating. Just making models is easy- at least with Autodesk. Don't know about mudbox.
2D art is easier than 3D. In 2D you draw something. The tools can get quite advanced but it is still something they are familiar with. Most people can intiuitively understand how the systems work.
3D art is far more complex than 2D art. 3D models are more than just point clouds and triangles. Topics like surface normals are a little more difficult. Creating rigs of 3D models is time consuming and a tricky process, and animating them takes time and skill. Texture mapping is usually explained readily enough, surface descriptions and shaders quickly get overwhelming to students. Encoding model data with spherical harmonics, creating subsurface textures, oil maps, and light scattering gets harder still.
The same with 3D programming. In 2D programming is geometry and trigonometry, subjects most of the students that age are comfortable with. It takes some explaining but you can talk about trig functions, where you use sine and cosine to compute rotations of objects, or work with (x,y) pairs. Several kids in the class will likely be able to help when their peers get stuck.
In 3D programming you are looking at a far more complex world. Linear algebra and the math of 3D spaces is typically not taught until the 2nd or 3rd year of college. Manipulation of transformation matrices is something most high school students will not understand. Explaining how to normalize vectors and compute dot products and cross products can be done but will take time and probably lose many students. Manipulation of 3D animation splines and knot coordinate computation will hold the interest of a few students but most of them would likely have abandoned the course by the time you've taught enough to slide a point along a curve.
No, at the high school level stick with 2D the entire year.
I do have to add that several people have been very snippy with me for no reason
Yes, it has been hard to watch. As this discussion is a poor fit for any of the established areas of the site it remains in the Lounge. The Lounge does not offer voting buttons, so people tend to get a little snarky when they don't see consequences.
I know I'm not the only one who has thought about moving it to a few places in the forum to gain the voting buttons. It breaks the For Beginners rules, is not about Game Design, or General Programming or any other programming area, it doesn't really fit production and management, business and law, writing, music, or any of the visual arts. The subject does not fit well in any of the technical, business, or creative areas, so it remains here in the lounge.
There have been several warnings issued to people who forget to be civil, but those are typically hidden from public. Usually some of the moderators not in the discussion have mentioned for people to watch their tone generally after issuing warning points.
I think the plan you described earlier -- with the exception of attempting to work in 3D -- is good for a course like this. Go get familiar with the tools.