SpaceClaim is the fastest solid modeler on the market, and it works beautifully in the context of scanned data. Bring in mesh data from anywhere and quickly snap sketches to the coarse mesh. Position your scans in the context of your existing 2D and 3D CAD data and match your new design to fit. Tweak models with surfaces that came from high-end reverse engineering product.
§ Read STL files, even if they don't form a closed mesh
§ Convert STL to facetted solids
§ SpaceClaim fast direct modeling tools, such as Pull and Move, can snap to scanned data
§ Automatically recognize and fit curves to cross sections
§ Snap and align geometry from high-end reverse-engineering software to satisfy geometric conditions
§ Turn scans into solids faster than ever before
§ Bring all your data into one location to make immediate design decisions
§ Automatically convert imprecise SketchUp data to precise surfaces like cylinders and cones.
§ Use add and subtract material from scan data for assembly and tooling
§ Create, edit, and visualize in 3D as well as 2D cross sections
§ Never get distracted with constraints, rebuild errors, and external dependencies
Below is a cross section of a precise solid sketched over a laser scan.