Warning of height difference
During calculation there can be warnings on the command line like:
Warning! Calculation point XXX has height difference of more than...
This is always accompanied by a green line on the noise modules layer for temporary data. This layer is specified in Global Settings . If the line is shorter than 50m, there will also be drawn a green circle around it on the same layer.
The lines and circles are drawn to make it easier to find out where the warning is triggered.
The value this warning relates to, is by default 2m, but can be changed in Global Settings .
The warning means that the program received a terrain profile where two consecutive points in the profile had a height difference of more than the set value. If you e.g. have a map with equidistance 1m, there should never be any consecutive points with more than that difference. When that happens, something might be wrong in the terrain data, e.g. one point on a height curve might have a wrong value.
In a new data set, you should always do a calculation of only one or a few points to see if there are any height warnings. If there are, check to see if these warnings have detected a real problem or if the data is ok. After having fixed this and/or adjusted the value for the height warning, start the big calculation.
NB! You should never start a big calculation if it results in many green lines. The drawing will escalate in size and might well cause a total crash because the memory gets filles up. It does _not_ help to freeze the layer with temporary data, the lines are created on that layer anyhow!