here an working example of my solution:
https://www.youtube.com/watch?v=-SSio2tMuDA
tutorial will follow

greetz
robert
PS: Can someone Tell me how i make editor commands in play mode? thx!
processUsesBrush = "0";
processUsesBrush = "1";
function grass(%this) {
//Make the size of the brush
ETerrainEditor.setBrushSize(2, 2);
//Set the Shape of the brush
ETerrainEditor.setBrushType("box");
//Change "grass1" to the material you like
%matIndex = ETerrainEditor.getMaterialIndex( "grass1" );
//Change "test" to a terrain id you like
ETerrainEditor.setPaintMaterial(%matIndex, "test");
//%curPos = LocalClientConnection.Player.getPosition();
//%x = getword(%curPos, 0);
//%y = getword(%curPos, 1);
//%pZ = getword(%trans, 2);
//ETerrainEditor.processAction(%pX, %pY, %pZ, "paintMaterial");
//ETerrainEditor.setBrushPos(getWord(%curPos, 0) + %x, getWord(%curPos, 1) + %y);
//Run the thing
ETerrainEditor.processAction("paintMaterial");
//$eventID = schedule(230,0,grass);
}
...
exec("./grass.cs");
...
%curPos = LocalClientConnection.Player.getPosition();
%x = getword(%curPos, 0);
%y = getword(%curPos, 1);
//%pZ = getword(%trans, 2);
ETerrainEditor.setBrushPos(getWord(%curPos, 0) + %x, getWord(%curPos, 1) + %y);
scripts/server/grass.cs (19): ETerrainEditor::setBrushPos - wrong number of arguments (got 4, expected min 3 and max 3).