raytracing problems / speed

[___mats___]

Hello -

I have been having problems using raytraced settings on my renders in LW9. using refraction and reflections I get weird artifacts (like double polys almost), rendering this with the classic camera, (it renders OK with the advanced camera but it is like X6 slower than rendering on LW8.3)

any ideas? why does LW 8.3 not have any of these issues and render faster?

thanks

[Sekhar]

I've seen artifacts like this when there are two polys on different layers whose surfaces line up. You don't happen to have duplicate polys, do you?

[___mats___]

no :( double checked (triple checked)

I know thats exactly what I thought originally, but no, it is not the case.

:(

[jameswillmott]

Can you post the object/scene?

[toby]

Using any shaders?

[___mats___]

hi guys,
thanks for the replies, I have tweaked a lot of settings on the scene, I will have to revert and see what was causing the problem, the only shader I was using was fast fresnel.

I will take a look and post a scene file

thanks,

PS I sent a scene file earlier to chilton also, awaiting comments