Why do my CAD files look so rough?
MeshCAM loads DXF and STL files, both of which represent your CAD file as a group of triangles rather then the native format used by your CAD program. When exporting from your CAD program, you will almost certainly have the option to pick the precision of the STL file that you are generating. Just be sure to pick somthing appropriate like .001” and you should be fine.
When you view the STL or DXF within MeshCAM you may be able to see individual triangles on curved surfaces. Don’t worry, if you used a tight enough tolerance when generating the STL file then it is unlikely that you will ever see a triangle on the finished part.
The conversion to triangles occurs in every CAM program even if it loads your CAD programs native format. The math to calculate a toolpath is much faster and more reliable for triangles than for other CAD formats. CAM programs that use native CAD formats do this conversion in the background even if it is not visible to you.
Using triangles to represent your CAD file does not lead to any loss in accuracy of the finished part.