Acc-u-Trans Translation Services

Q. When you say TTI uses Feature-Based Native file conversion, what does that mean?

A. Feature-Based Native file conversion is one in which all of the original geometry and geometric features of the model in a source CAD system file are re-created in a specified target software application. For example, if the source is CATIA and the target application is Pro/E, all of the geometry and geometric features are re-created directly in Pro/E. The method used by TTI completely bypasses the use of neutral files such as IGES, STEP, etc., and the potential errors that neutral file translations can create.

This means that the translation we bring to you is ready to use, fully modifiable and accurate. It will look and function as though it was created in the target CAD system. No more wasted time spent in further cleanups or "healing".

Q. When I import a neutral file in a target CAD system and save it, I get a native file extension which tells me it is now a native file. What is the difference between that native file and the native file you are providing?

A. What you have is a native file with an imported object in it, often referred to as a "dumb solid." We at TTI define our file conversions by levels. Your ability to manipulate the file is limited by your specific applications level of support for imported geometry. Usually you can add protrusions or cuts but it is very difficult to redefine, move, resize, or reshape them.

At TTI we provide you with file translations that allow you to manipulate the geometry with all of the functions and capabilities of your specific CAD application.

Q. Can TTI translate every feature of every CAD system?

A. TTI has identified and defined two levels for CAD file translations. The first level is available now and the second level will be available in 2001. See the Acc-u-Trans TM information section for a more detailed description of the characteristics of the two levels of translations.

Q. What are the advantages of Feature-Based Native file translations?

      A. The advantages of Feature-Based Native file translations include (but are not limited to):

      • Fully modifiable features and entities that have better accuracy and are easier to work.

      • Smaller and more efficient files.

      • The ability to share CAD files across an organization or across an industry, regardless of the types of CAD systems being used by the parties sharing the files.

      • The realization of interoperability and collaborative engineering because the Feature-Based Native file translations pass all of the design features over to the target file rather than just creating a "dumb solid."

Q. How will Feature-Based Native file conversion help me in my job?

A. With a Native target file to work from instead of an imported neutral file, you will be able to work more efficiently and accurately. Your new part files will be immediately modifiable, both parametric and associative. In addition, because of the inherent accuracy of TTI's Feature-Based Native translations you will know that the converted file is accurate.

Q. What are the losses associated with Neutral File Formats compared to files translated by TTI's Acc-u-TransTM service?

A. Neutral file losses occur in two main areas: geometric accuracy, and entity association.

  • ACCURACY: Each CAD system defines geometry differently. You may not see the errors, but they show up in variations from the true surface geometry or intersections that may overlap or don't meet. That is why there is a need for healing in order to help in the repairs. This is only one example of the many errors that can occur. Your manufacturing tolerances can be used up by the errors.

  • ASSOCIATION: Modern CAD software, through associated parameters, defines the geometry, conveys tolerances, notes, dimensions, and even material specifications. Neutral file formats do not support these entities. When the file is exported to and from a neutral format valuable information is lost.

  • Q. If a neutral file translation opens, it's correct … right?

    A. Wrong! If it opens, that only means one of three things:

    1. Everything was translated correctly.

    2. The importing application did not recognize that there are errors in the geometry.

    3. The importing application made some assumptions and repaired them.

    You still have no idea whether the geometry is correct or not. TTI's tools and translation service verifies that the target file geometry matches the source file geometry.


    Q. I've been using IGES/STEP and it seems to work fine, why change?

    A. The neutral file conversions are often quite adequate when all you need is a dumb solid that will be used for manufacturing or packaging purposes. If the converted model is going to be used in the design process there are four basic reasons that neutral files may not be well suited for the job:

        1. ACCURACY: You don't really know if it has been converted accurately. You just know that you can open it and work with it. Unless you have the Native source file, and some comparison tools to analyze the Native source and target geometry, you do not really know that the converted geometry is accurate. Any of the subtle errors that go unnoticed and result in rejected, reworked molds, and scrapped parts were just chalked up to tool chatter, or improper feed rates, or some other reason. People rarely do more than a cursory critical dimension check of the CAD geometry and assume it is fine.

        2. MODIFIABILITY: When your customer, for example, decides to change a surface that defines the core or cavity geometry of a mold, wouldn't it be much quicker to simply regenerate the mold base with the updated part model file? With TTI's process the modified surface will automatically update to the correct new geometry. Your customer's revisions should have little or no impact upon your design costs, as opposed to IGES, STEP and other neutral file formats.

        3. TIME SAVINGS: Depending upon the source and the target, there can be a lot of time spent on the cleaning and healing process or even redrawing the model. Because there's no need to cleanup or heal the file, TTI's translation services will get the job done in a fraction of the time spent on neutral file translations.

        4. COST: TTI's Acc-u-TransTM CAD file translations will drastically reduce the cost of converting CAD files from one system to another by reducing the manual effort required. Converison costs can be reduced by 50% or more.

    Q. What are the accuracy comparisons between working with neutral file translations versus working with Feature-Based Native file conversions?

    A. Exporting a CAD model file to a neutral file format often induces errors. TTI's proprietary Feature-Based Native process does not induce the errors to begin with, therefore we don't have to waste any valuable time "healing" the model files. In addition TTI Acc-u-TransTM service uses a Mirror Model Comparator to automatically compare the source file with the target file and an automated check (LINK TO PRODUCT REVIEW) to insure that the translated file is accurate.

    Q. Can you give me some additional examples of what could be wrong with neutral file translation?

    A. Some of the most common examples include:

    • Errors introduced in the geometry. Because neutral file formats must take a "least common denominator" approach in order to accommodate many CAD/CAM packages many compromises will be made.

    • Lost design intent. For example, a dimension that defines geometry will no longer be associated with any geometry. Sometimes it is not even a dimension anymore. Tolerances that are attached to specific features are lost.

    • Lost associations, parameters and other manufacturing information.

    • Neutral files are typically large (3 to 10 times the size of the native file or more).

    • Difficult repairs to damaged files. Most CAD/CAM applications do not directly support modification of imported neutral files.

    • Difficult to incorporate updates and revisions to the original part file after you begin to work with an imported file.

    Q. What data is lost by not going Feature-Based Native?

    A. You get the basic geometry shell that may contain errors. The features and history are lost.

    Q. What will I get back from TTI?

    A. A native CAD file in the requested target system that will be fully modifiable and accurate. It will function as though it was created in the target CAD system.

    Q. Isn't a Parasolid translation the same as a Feature-Based Native translation?

    A. No. Virtually all of the CAD/CAM applications can export and import a Parasolid file. The key is that they will only support an exported version of the file. They won’t support exporting a Parasolid file in native Parasolid format. Therefore, how do you get a native Parasolid file from the source CAD application to begin with. The answer is, you don't.

    Q. Do I lose anything in Parasolid translations?

    A. Yes, it is just like exporting to a neutral format such as IGES or STEP. In fact, you would be better off considering an exported Parasolid is about the same as an IGES or STEP, it is about the same functionality you will get when you are done.