When we reviewed Vellum Solids 99, we praised its solids-modeling features but found fault with what appeared to be rough edges in the code development. Since that time, Ashlar has polished the program considerably, adding even more features for the intuitive handling of solid shapes. Also, the new version can read AutoCAD 2000 files. And, because we now live in a world where G4s with more than 512 MB of RAM are increasingly common, most performance problems are solved.
Vellum Solids is an industrial design program, not a CAD program. Industrial design is the discipline that gives rise to egg-shaped cell phones, the iMac, and exotic toothbrush handles; CAD has more to do with the world of rectangular windows and machined parts, rather than injection-molded ones. Industrial designers tend to prefer to work with curved, free-form solids and surfaces, modifying them until they look right for a design. And Vellum Solids 2000 excels at this kind of work, offering a nice assortment of solid forms, convenient tweaking tools, and every common variety of surface-generating tool. This is in contrast to most modelers, which work from wireframe designs, and fill in solids and surfaces as the last part of the process. Designers tend to find that once they get used to the Vellum approach, they rarely revert to wireframe-based designs. Part of this conceptual shift is aided by Drafting Assistant, a Vellum feature that identifies control points for curves and solids when the cursor passes over an object.
Look at the shapes, shadows, and tile edges in this Vellum Solids 2000 example. The surprise is that generating such drawings is easier than you think.
This new version is based on the ACIS solid modeling kernel version 6.01, a big jump from version 3.01, which was used in Solids 99. This provides much better performance when deriving 2-D cross-sections from solid models. The new version also offers eight new solid blend types and nine new solid chamfers. (A blend is a curved cut along an edge; a chamfer is a slanted cut along the edge of a curved solid. Most CAD programs do both of these poorly.) This version introduces surface matching, so that surfaces of type G1 (tangent continuous surfaces, such as a hemisphere joined to a plane) or type G2 (curvature continuous surfaces, such as an egg) can be joined smoothly. You can also introduce rows of control points to surfaces, which allows easier manipulation, and raise the degree of the polynomial describing a curved surface, which allows you to produce more variegated, complex surfaces. A new Convert Object Type command lets you change curves such as circles and ellipses to vector splines, and you can then add control points to the splines to modify their shapes. The Convert Object Type command also converts any of the Vellum solid primitives to surfaces or curves.
These features, which sound complicated but are quite easy to use, put Vellum Solids 2000 at the top of the heap for industrial design -- well ahead of AutoCAD 2000's modest efforts in this direction.
The program does have a few trivial irritations, however. Somewhere in the wild blue yonder beyond four thousand bucks for a CD, you might expect something more convenient than a giant, clunky, assemble-it-yourself ring binder for documentation. At least the documentation itself is thorough and authoritative. The product also requires a finicky dongle hardware key that at least works off the Mac keyboard. To be fair to Ashlar, though, some sort of product key is probably needed, or else exactly one copy of Vellum 2000 would sell into every design school in the country. Another mild complaint is RAM usage -- the product is notably faster with more than 256MB, but at a price near $5,000, Ashlar is expecting the product to sell only to serious professionals. These complaints are definitely minor though, and Ashlar gets high marks for this standard-setting program.