Has anyone come across this problem before ? When applying a Rail Object to some MX strings, the last portion of Rail Object becomes skewed. Not so noticeable when using say highway guardrail, but becomes more apparent when using more of a barrier/wall type style. Changing the spacings etc has no effect i.e. the last part still at an angle.

Maybe its got more to do with my MX string creation than DVSP ?? Although bearings on the MX string look fine in MX…...........

This is not an MX related problem, it’s caused by the way that MAX/VIZ calculates the bearing of the shape at the last point on each spline. This is a known problem in MAX/VIZ - and a frustrating one. The geometry of the DVSP rail object is being generated based on the tangents that are being read from the parent shape.

We did quite a bit of work on swept objects, rail objects, and the DVSP object placement position controller to try to overcome this problem (you may remember seeing animated vehicles suddenly skew when reaching the end of a parent shape? - this is caused by the same issue). In this case, it looks like we need to take another look at the rail object plugin to find out why this problem isn’t being caught in some cases. If you could provide us with a sample shape object that exhibits this problem, that would be great.

In the meantime, adding a “normalize spline” modifier to the base shape and adjusting the “segment length” parameter usually solves the problem. If you haven’t used “normalize spline” before, it is like generating a master string in MX using major option EDIT 027 with REGU specified in field 2.

Bruce Harfield - 04 January 2007 08:49 AM

In this case, it looks like we need to take another look at the rail object plugin to find out why this problem isn’t being caught in some cases. If you could provide us with a sample shape object that exhibits this problem, that would be great.

Thanks for the “normalise spline” tip…....... I’ve attached a zipped max file that contains a sample shape object with the error for you to look at. Like I said, it doesn’t happen all the time so not a major problem, but would be nice to have fixed.

cheers Mark

Thanks for the sample Mark.  As a result, I can confirm that the source of this issue has been detected and the problem is now solved ready for inclusion in the forthcoming release of DVSP V3.1.

Good news Bruce. Thanks Mark

Sweet.  The forum’s working

My work around was to either normalise the string and / or fudge the end points.  I’ve found sometimes our strings haven’t been tieing in nicely with bridges and barrier so I’ve been fudging them anyway and if there was a skewed post at the end, I’d hide it in the bridge / barrier geometry.