I have grass/weeds (.for files) showing through runway boundary markers that I created in Sketchup. Have tried various attributes in sketchup for the marker objects to no avail. Where the grass and the markers overlap one is not aware of the other it seems. The grass appears to have grown through the object. Have tried laying the .for polygon first then the objects on top but no luck. This has been a problem for me for a couple of years of scenery development for my local regional airports and one I have not found answers to myself or in my various searches, so any help would be greatly appreciated.