Open Design Foundation

Collaborating in a mixed environment (0.0.2)

Selection of standards

A major goal of Opendesign.org is to provide a framework for diverse individuals to collaborate on design projects. We want the barriers to entry be very low. Inevitably, however, one of the first problems which will arise is what development environment to use. This is the same problem faced by any design project, the only difference is that the individuals are not working for the same company with the same level of available resources. Ideally everyone would have access to one particular very highend solid modeling package. This is not possible. The same is true for every aspect of the project from analysis to documentation. This document is an attempt to outline the basic procedures for approaching this problem.
In general there are two conflicting needs. That of accessibility and that of capability. If we pick the lowest common denominator then everyone who wants to will be able to participate. But at the cost of inhibited the design performance. If the highend is only selected then only those who have access can contribute. This problem is particularly compounded by market fragmentation in solid modeling. Thus, not only what level but which package. CAD packages are for some reason a particularily contentious subject for designers. Likely due to the large financial and time commitments. Let us first explore how the CAD packages can be integrated for a Opendesign.org project.

Working in a mixed CAD environment

Initially we recommend that a Master Modeler CAD (MMC) package be selected for the project. This package should be of high enough capability to complete the project. For example, if complex surfaces are important to the project then it would not make sense to select an MMC that doesn't support surface generation. It should be a package which the project leaders and most of the sub-project leaders have access and strong familiarity with. Beyond this it is preferably that the package run on as many types platforms and OS's as possible, this makes it more widely available. It should be stated, at this point, that FDF does not officially support any particular package or environment.
Now that we have selected the package how do we work? Let us first consider the simplest scenario. If we assume that the selected CAD package is "A" then a designer who is also using that package is in the best situation. The following figure illustrates how they would interact with the data vault.

In the second scenario the users of a different solid modeling package would need to access the models via a translation. Thus, the data in the master model vault would have to be translated to a neutral format, which we are recommending (for the time being) STEP. In a perfect world we could just use STEP files (or some other format) for the master model, thus eleminating the need for a MMC. For the time being this is not feasible, but there are some potential emerging defacto standards which may provide a superior future collaboration vehicle. For the time being the translation from the master model to the STEP vault will need to happen either automatically or manually, depending on the system setup. The user of CAD system "B," the other solid modeling package(s), will interact with the data vault as follows.

Because it is desirable to keep the native model information, a special native vault is provided for model submission and maintenance. A project leader who has access to CAD-A would then periodically update the master model assembly with the updated geometry from the STEP vault.
The next level of user is the 2D CAD user (or even a non-CAD designer). At this level the designer must interface with a collaborating user who is either using the Master model CAD package (CAD-A) or another solid modeling package (CAD-B). The 2D designer fetches drawings form the dxf drawing vault. The collaborating user must then build or modify the solids based on the 2D design work and then submit to the Data Vault for the CAD-C user as shown below.