How to build the NeL landscape.

WHAT DOES MEAN 'BUILD THE NeL LANDSCAPE':
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Once you have created your tile bank and your landscape zones, you will need to preprocess your zone
in order to:

- Weld the boundary vertices of the zones
- Light the zones with shadows casted by the landscape and the static objects (like trees, buildings..)

REQUIREMENT:
------------

Before building the landscape you must have:

- Installed Cygwin tools and set the PATH properly. (Under windows)
- Compilated some binaries and putted them in the "bin/" folder. (zone_dependencies.exe, zone_welder.exe, zone_lighter.exe. zone_smoother.exe is not use anymore)

DATA EXPORTATION:
-----------------

You have to export those data:

- The .zone files in the "zone_exported/" folder. (NeL landscape zone files exported from 3dsmax)
- The .bank file in the "bank/" folder. (NeL bank edited with tileedit)
- The .ig files (named like the zone) in the folder "ig/". (NeL instance group file exported from max)
- The .shape files (for trees, building or every things that cast shadows on the landscape) in the folder "shaped/"
- The .tga files (for the shapes used for alpha blending and for displace tiles) in the folder "maps/"

CONFIGURE:
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Configure the cfg/properties.cfg file.

bank_path is the bank path
ig_path is the ig path
shapes_path is the shapes path
maps_path is the maps and displace tile path
additionnal_ig is the list of additionnal ig to load
sun_direction is the sun direction
load_ig is 1 to load ig, 0 to not load ig
shadow is 1 to compute shadows, 0 to not
oversampling ALWAYS 0
shadow_bias shadow bias is the bias used to avoid self shadowing
softshadow is 1 to use soft shadow
softshadow_blur_size is the blur size in meter
softshadow_fallof is the length of the foloff effect of soft shadows
softshadow_shape_vertex_count must be 10
sun_contribution use the direct lighting (normal)
sky_contribution use the pseudo radiosity lighting
sky_intensity pseudo radiosity intensity
global_illumination_cell_size cell size for the pseudo radiosity algorithm. Smallest, finest.
quad_grid_size Size of the quad grid side in meter. Should be a power of 2. (optimisation)
quad_grid_cell_size Size of a cell of the quad grid in meter. (optimisation)
cpu_num Number of CPU used to calculate the lightmaps. 0 for automatic detection.

COMPUTING:
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0_clean_all.bat - clean all the directories.
1_build_dependencies.bat - build dependencies files. Each zone will have a dependency file in which is listed the zone that cast shadow on it.
 -> generate the .depend file in the folder zone_depend/ 
2_weld.bat - Weld the zones. -> generates the zonew files in the folder zone_welded/
3_light.bat - Light the zones. -> generates the zonel files in the folder zone_lighted/

All the building process in incremental, ie, if you modify only ONE .zone file, the weld pass will modify the zonew file and each neighbor of
this zone. The light pass will relight only the modified zonew file.

The .zonel files are the final zone file. They are loaded by the engine. (see snowballs 2 source code for detail).