I am a beginner with Blender. I only need to create a 10-block 3d object (pic 1). I created this object by having 10 meshes and 10 wires of the same size on top of the same mesh. The rendered image has very rough and irregular edges. I don't know whether I have done something wrong in the Material section or the wireframe modifier (pic 2).
For what it looks like you're trying to do, it would probably be best to use Freestyle, which detects edges in your scene and outlines them. That way you can forget about the wireframe and let Freestyle handle that.
You turn on Freestyle from the Render settings, the leftmost tab of the Properties panel.
It has one option in the Render tab, whether line thickness is absolute (pixels) or relative to image size, and all the rest are in the Render Layers tab, one to the right. Here you can tweak everything about Freestyle—the color and thickness of the lines, which edges are drawn over, and a whole lot more.