Photometric Light Shadow Type Issue

[CJI]

I did an extensive search here and through google but couldn't find anything that addressesd this rather strange issue i have come across. If i have missed a post on this or i am just being a little slow today please let me know.

 

I am making a very simple trough light on a bulkhead that you see so often in retail that provides that nice lighted halo around the ceiling. So i lofted a spline profile around the ceiling and intended to use a simple photometric light emitting from a line shape but I get a lot of light bleed where the light seems to be penetrating the geometry. I've not encountered this before but its at its worst when using raytrace shadows and better with mental ray shadows. The strangest thing is that this does not occur when the gemoetry is box modelled but happens when both loft and sweep are used, also happens regardless whether GI and FG are used. I thought I would fire it at you guys and see if you see something I havent't yet.

 

Using Max 2009 and Mental Ray.

 

Simple examples below.

 

Cheers

[CJI]

Ok i seemed to have found a fix. I had converted my loft with an edit poly modifier so didn't have access to the loft settings. I went back and lofted it again and systematically changed each setting. It turned out the culprit was the the smoothing under surface parameters. It had no visible effect which is why i probably glossed over it. Turned that off and 'voila' we have accurate light interaction. If any one can or wants to explain why this happened I would love to know, i am not super experienced with the Lofts in Max as of yet.

 

Cheers