ETL Height & Paged grass

I am Tabib Ahmed(Graphics Designer) working with OGRE in application level. I want to make a terrain which is 20sqr. mile area in real field. I can't customize it properly. My area is full of hills, sea, river & uneven land also.I need to create grass in customize way. I want to know :-
1.Last limit of height 2.Is it same of 3ds max height, 3.Remove grass where I want(Like road, Housing area)
I am waiting on Your answer.

Tabib Ahmed

1 - Height is used as a FLOAT in ETL, so the actual last limit of height depends on how you save it, if you are saving it in a 16bit PNG, then you have 65536 distinct height values, if you want to have a 10cm height resolution, it means you can have heights between 0 - 6553 meters, if you wanna have 5 cm height resolution, then you can have heights between 0 - 3277 meters etc.

2 - Paged Grass allows you to define a coverage map, this coverage map is laid on your terrain and depending on the values in coverage map the grass is placed. The value 0 in coverage map means no grass where 255 means a lot of grass, so you simply paint a coverage map for your terrain and define the densities of grass in it, then pass that coverage map (density map) to paged grass...

ismail,