sorry - back to this again. I noticed these light terrain streaks are more pronounced when the compile is darker - the darker the terrain the more pronounced the light streaks at the seems. Im trying to pronounce the shadows of the stones by turning the light down a little - but then i get these streaks more pronounced - maybe a better trick, reduce bounce (how?) or something?
do ambient, ambientlight and suncolor all effect terrain ?
Ok, by "brushes" I'm guessing you mean solid brushes and not LOD Terrain. It is probably still a texture problem. You should try an original one like "misc_outside/nu_grass_set2_sp".
To make the shadows sharper, highlight the faces of the grass near the stones and hit key S. Look for the "Intensity" and "Density" windows. Not sure which, but one of them makes the shadows sharper if you change it to 1. Doing that will also increase the compile time and probably lower preformance (fps). Try lower numbers (like .2) and increase until it looks good. But don't go over 1.
If you make suncolor 70 70 70 in worldspawn, you will have full sunlight. Ambientlight is how bright the shadows are, so set it lower to darken them.