leue@galen.steinmetz (03/22/89)
I've owned Claris CAD for a couple of weeks now, and I've played with it enough to get a decent feeling for the program. Here are some notes. They don't come close to providing an exhaustive description of the program, but they may help people in comparing it with other Mac CAD tools. Overall, I'm impressed with the program. The user interface is VERY smooth. It's essentially a large superset of MacDraw II, and so for me, a long-time MacDraw/I/II user, much of CCAD seemed natural to use. The forte of the program is a large battery of geometric constraints and object snaps which allow very precise placement of graphic elements. Claris calls this collection "tools, methods, and modifiers". In this nomenclature, "tools" are what you'd expect -- those icons you see at the left of the page. In addition to the MacDraw II tools, you get fillet/round/chamfer, dimension tools, ANSI circle "crosshairs" (yay!), B-splines, etc. To avoid cluttering the screen, most tools have "pull-right" pop-up extensions which allow several tools to fit into one icon: e.g., the "rectangle" tool also has a "square" tool. Whichever tool version you pick replaces the original one in the "visible" tool icon, thus minimizing the number of times you have extend the pop-up. Like MacDraw II, double-clicking the tool locks it in for multiple use. No matter what tool is selected, there are a number of "methods" and "modifiers" available to change the way the tool works, either alone or in conjunction with graphic features already on the drawing. The "methods" are specific to the particular tool in use: for instance, if the circle tool is selected, then the varying methods available for specifying the circle include two-diagonal-points (the normal MacDraw/Paint method), center-radius, three points on circumference, two points on circumference and radius, etc. "Modifiers", on the other hand, are selected mostly independently of which tool is selected. The modifiers allow placing of a new graphic element with great precision in some desired relationship to another object or objects. Modifiers include "point on line", "center", "parallel", "perpendicular", "tangent", "intersection", "invisible intersection", etc. You can use more than one modifier during the creation and alignment of an object. For instance, if you want to draw a straight line which is tangent to two existing circles, you select the line tool, double-click the tangent modifier, click on the edge of the first circle, drag to the second circle's edge, and release. Viola! For me, the slickest and most "gee-whiz" feature is the "polar duplicate" menu selection. You select a graphic element, and then you can say, in effect, "replicate this element N times around the circumference of a circular arc with its center at X,Y, and do/don't rotate each new element so that it faces the center of the arc." I was able to draw a 60-tooth gear by drawing its hub, rim, tooth root circle, zooming in, drawing a single tooth, and then duplicating it over the full 360 degrees. Try that in MacDrawII! Oh, yes -- some other features that I really missed in MacDraw II and are present in CCAD: you can draw a box using the rectangle tool and then "break apart" its sides to make 4 independent lines. Conversely, you can take a bunch of lines and arcs and join them together into a true object which can be pattern filled. This "join" operation is different from and in addition to the normal "group" operator. Also, AT LAST - real dashed lines which work for circles, polygons, etc. Misfeatures, Limitations: It's no speed demon on a Mac Plus. Too bad, because MacDraw II is more than satisfactorily fast on the same box. Oh well, it should scream on a IICX, heh heh. It's also a bit pricy (list $800) compared to say, MiniCad +, which also includes a 3D editor. I've heard it compared unfavorably to Canvas 2.0, but I don't really think it's a fair comparison: one's a drafting tool, and the other is more of an illustration tool. (just my opinion) I'm very unhappy with the way it prints on an Imagewriter LQ. Don't mistake me -- this is not related to the other notorious LQ printing problems. MacDraw II prints just fine on this printer. However, if I take the same drawing and import it into Claris CAD, the printout looks lousy. There are distinct breaks visible every few millimeters on the edges of circles. Lines don't print out at the right thickness -- a 1-point line, for instance, prints out much thinner than it should. If you change it to a 2-point line, it suddendly "jumps" to a much thicker line. Things look fine on the screen. My impression is that the printing algorithms are optimized for use with plotters, not printers. I suppose this makes sense with a real CAD program, but it's disappointing. Nevertheless, I consider these problems to be warts on an otherwise excellent design tool. -Bill Leue leue@crd.ge.com, uunet!steinmetz!nmr!leue