Did I bring any pieces of wood?

Last time we left with this plan:
	I'd create a function that adds a cylinder to the tree
		Parameters would be the start, end, and radius
	Then in class:
		Try out the make_tree function with a single branch section
		Make the branches curve

After touring the draw_branch_section function...

First question:
	Does make_tree work?
	We can have draw_branch draw only a single straight section of fixed width to start

Next:  Curved branches!
	They shouldn't look segmented
		Bamboo is segmented
		It's grass, not a tree
	Joining sections together:
		It'd be nice if one section started where the last one left off
		In a way, draw_branch_section is organized wrong
			We're interested in rings now!
			start and end should really be rings
			A ring is a list of vertices
			To calculate one, we need a point, direction, and radius
	A proposal:
		calculate_ring_points calculates the points for a ring, given these parameters
		We always cross with the x axis
			What if we hit it?  Unlikely if trees grow upward
		We store a ring as a list of vertex indices
			So we can recycle vertices
	A concern:
		Is there any chance we'll end up with twisted sections?
				
Lab:
	Create a fall scene with barren trees
		They should have bark, not brick
		Make leaves on the ground
		Generate at least a few trees in different places