I am using Vue Esprit 6 and have a question. 

When I add an item to an Eco, I can type a number into the setting Presence that will increase the number of plants, object, etc.  However, when I look at an Eco from e-On, there are always two sets of numbers separated by a colon i. e. (-30; 50).  Since I can type in numbers corresponding to that sequence and otherwise, what do they represent in detail and what effect do they have on the terrain?

Thank for your help.

These figures only appear when the distribution is driven by a function. Typically, with 2 different objects to populate the first object in the list will have a -1.000 to 0.000 range, and the second a 0.00to 1.000 range, meaning that first object will apper in the black areas created by the function, and the second in the whites..If 3 objects, range will be divided by 3, and the middle range object will appear in the grey levels.
If you simply want to have more, say maple trees than birches, without the need of a particular visual pattern in the population, simply raise the presence of the maple to 1.5, and reduce the birch to 0.5

Whoa! That does make my head spin. Much appreciated!

Attached Link: Great Singapore Duck Race

Interesting coincidence, Cincinnati has the Rubber Duck race each year and they claim they will have 85,000 in the race also.  I wonder how many polys that would be?