繁體 简体

Q&A: Transform translation is too large: ACIS Error

Question
When I perform a ray trace, the message/macro window displays the following message:

Warning: Possibly defective Object 1 is being added to the ray trace.
ACIS Error: Transform translation is too large.

Synopsis
ACIS Error: Transform translation is too large

Solution
This error message is due to the position of the object. When objects are separated by large distances, the accuracy of their location is diminished. ACIS is providing a warning because this accuracy is now outside their tolerance range. The dynamic range of the ACIS CAD engine is from 10E-006 to 10E+006 mm (1 nm to 1 km).

Objects which are dimensioned or positioned outside of this dynamic range (either too small or too large) run the risk of producing inaccuracy in the ray trace.

The reason for this limitation is that the variables for the CAD dimensions can only retain 16 places of accuracy. So the program could retain a location for an object as 87654321.12345678. Because these values can experience roundoff errors, ACIS “guarantees” accuracy to a range of 12 decimal places, so a location of 654321.123456 can be trusted to within .000001 mm (1 nm).

This dynamic range should allow an object to be located at 999999.999999 (1 km). Your object at 30,000 mm should be OK. It appears that ACIS has decided to warn users for an even tighter range. I guess I would not view this as a bug since it is a “warning message” rather than an “error message”. If you see that warning, you might want to examine the ray trace results and make sure rays are not ignoring the distant object.

30051 新竹市經國路二段160號9F-8
Tel : 03-5359299  Fax: 03-5358908
統編: 28521213

光學軟體設計領導者

© 2018 All rights reserved. Setup by Eidea