Pro/JR. offers the same parametric modeling found in Pro/Engineer but without several add-on modules. The solid modeler is based upon a complete history-based parametric definition of geometry rather than on creating static geometric shapes.

PTC's design philosophy has two shortcomings with its approach to parametrics. First, all parametric geometry must be created inside of Pro/JR. via 2-D constrained sketches. This means existing geometry from other CAD systems is not usable for parametric design changes or modifications. Second, when major changes are required for Pro/JR. parts, it is often quicker to recreate the part from scratch rather that determine which feature relates to another in its constructive history.

Getting started. Overall, using Pro/JR. gave little surprises. While its menu structure does not adhere to exact GUI standards, its layout and use is logical. The menu structure is based on a hierarchical scheme that leads the user through the next required step for any given operation. Several special functions, such as single clicking on a circle for radius dimension, give quick control of commonly used options.

While models created in Pro/JR. are upwards compatible with Pro/Engineer, models created in Pro/Engineer are not supported in Pro/JR. But Pro/JR. does support a range of standard file and model import and export formats. As for utilizing existing data from DXF or IGES, Pro/JR. falls short of the entire industry since it only allows DXF data to be imported as 2-D data to its Drawing file. An entire 3-D IGES model may be imported into Pro/JR. as a base feature with new features added to it. However, parametric editing is not possible with the original base part.

Getting started with Pro/JR. is much different than other products in the industry. It does not have primitives, so all geometry must be created as 2-D profiles. When the geometry is fully constrained, it is made into protrusions to make it a solid. Once an operator gets past Pro/JR.'s three different plane definitions for creating sketches, using Pro/JR. is similar to other products.

Once the geometry is created it must be manually dimensioned or have constraint modifications applied to it. By using the Regeneration menu, the system checks for over/under constraint situations. Under- constrained sketches are not allowed; all dimensional constraints must be solved.

Dimensioning is quick and versatile. Dimensional values are the constraints which are automatically labeled with incremental constraint names. These have no true numeric length or size displayed at this time. Upon modification, the actual value is displayed. It can either be made into a new value, or a relationship of other labeled constraints or equations can be keyed in.

2-D links. The associativity of Pro/JR. makes it really standout with dimensions. Not only are they for driving the geometry, they are also used by the software for annotation in the Drawing mode. Bi-directional changes are supported from the drawing back to part and vice versa. Further system performance is provided by quick system-generated View Scale, Detail, and Section labels. These start out as definitions the operator keys in for creating view sections. The data is used for annotation of the views once these views or sections are located on the drawing. This makes annotation of multiple-view 2-D drawing almost automatic.

Pro/JR.'s Assembly support allows mating of parts within an assembly based on terms common to the assembly discipline. Commands such as mate, align, and orient are used rather than defining shape locations, specific plane definition, or coordinate values. The placement data becomes part of the parametric features database, rather than a static location.

While its tools are wonderful, getting to know Pro/JR. takes some time. The weak link is that it cannot utilize existing geometry from other CAD systems for parametric modeling. Since installation is still UNIX-type in its procedures, PC users will find it more difficult to install as compared to other products that offer typical "setup.exe" install methods. Shortcomings aside, Pro/JR. is offering the competition a tough fight for dominance in the mid-range solid-modeling market.

A similar product:

AutoCAD Designer--Autodesk, 111 McInnis Parkway, San Rafael, CA 94903; ph: (800) 551-1490.

Spec Box

Pro/JR. 1.1

Required Hardware: Windows 95 on Intel Pentium; Windows NT on Digital Alpha AXP, Intel Pentium, and MIPS R4000 Family; UNIX workstations from Digital UNIX, HP-UX, IBM AIX/6000, Silicon Graphics IRIX and Sun Microsystems Solaris. 32M bytes RAM, Ethernet adapter, CD-ROM, and 200M bytes free disk space.

List Price: $4,995.00.

Parametric Technology Corporation, 128 Technology Dr., Waltham, MA 02154; ph: (617) 398-5000; FAX: (617) 398-6000.