so in a sketch you can snap to a line a curve an end point a point or circle center
the constraints also offer some ability to not snap but force a line curve into a relationship
works well for certain parts
Snapping and constraings to a certain degree replace here what Rhino and Alias just offer as plan sapping.
Great thats and useful but not enough.
in 3d sketch I cannot snap to a mid point of a line a mid point of a curve
in 3d sketch I need to project geometry into the sketch to be able to snap to it creating overhead work and a more complex sketch
in 3D sketch I cannot snap a spline vertex handle point to something like a point of a curve
in Alias you can select a curve and interactively subdivide it so you have snap targets
in Fusion I would need to add extra lines to for example cut a circle into 2 3 4 5 segments to snap to ( too much work and added geometry)
here is a video explaining this also showing some general frustration with the sketch interface
