renderable splines and solid objects

Hi all!

does anyone know what these errors are? medium preset.
walls are solid objects, mortar renderable splines set to 2 cm..

looks like co-planer faces.
Are the splines intersecting the walls?

yes, they are. but with the size of the spline they should be 1 cm outside the wall.

stephan

it must be GI shadows then. Try making them not visable to GI

getting a bit better, but there are still some artifacts

why use a spline? why not just map them onto that surface

yeah, thats what i did in another project. works fine. but the map is so big, you can not see a s*** in the viewport.
so i tried the spline thing..

stephan