Slope can be measured in degrees or in percent slope.
Fixed Size
Allows you to specify a length for all the slope vectors.
If this is not checked, the length of each slope vector will be computed by multiplying the Length value given and the amount of slope. Also, the slope vector will not be drawn if it is outside of the minimum and maximum range.
Auto Size
This will compute a reasonable value to use for computing the Length of each slope vector.
