make 3d model from dem file

DEM importer_for_blender.py

import bpy
import bmesh
import bpy_extras
 
list_h = []
res = 0.0
rows = 0
cols = 0
min_h = 10000.0
scale = 1.0
 
print("DEM Importer")
 
def readMesh(filename):
    i = 0
    j = 0
    c = 0
    nodata = 0
 
    global list_h, res, rows, cols, scale, min_h
 
    for lines in open(filename, 'r'):
        list_c = lines[:-1].split()
        if list_c[0] == "ncols":
            cols = int(list_c[1])
        elif list_c[0] == "nrows":
            rows = int(list_c[1])
        elif list_c[0] == "xllcorner":
            west = float(list_c[1])
        elif list_c[0] == "yllcorner":
            south = float(list_c[1])
        elif list_c[0] == "cellsize":
            res = float(list_c[1])
        elif list_c[0] == "NODATA_value":
            nodata = int(list_c[1])
        else:
            for c in list_c:
                list_h.append(float(c))
 
    #Scale
 
    wx = res*cols
    wy = res*rows
    scale = wx / 10.0
    res = res * scale
    print(rows, cols, west, south, res)
 
    for h in list_h:
        if h < min_h:
            min_h = h
 
class ImportOperator(bpy.types.Operator):
    bl_idname = "object.import_aaigrid"
    bl_label = "Import ArcInfo ASCII Grid"
    global res, list_h
    filepath = bpy.props.StringProperty( subtype="FILE_PATH" )
 
    @classmethod
    def poll(cls, context):
        return True
 
    def execute(self, context):
        print(self.filepath)
        readMesh(self.filepath)
        mesh = bpy.data.meshes.new("Terrain")
        u = 0
        v = 0
        verts = []
        faces = []
 
        for h in list_h:
            vert = [-5.0+res*u, 5.0-res*v, (h - min_h)*scale]
            verts.append(vert)
            u = u+1
            if u == cols:
                v = v+1
                u = 0
 
        for y in range(rows-1):
            for x in range(cols-1):
                face = [y*cols+x, y*cols+x+1, (y+1)*cols+x+1, (y+1)*cols+x]
                faces.append(face)
 
        mesh.from_pydata(verts, [], faces)
        ob = bpy.data.objects.new('Terrain', mesh)
        scn = bpy.context.scene
        scn.objects.link(ob)
 
        return {'FINISHED'}
 
    def invoke(self, context, event):
        wm = context.window_manager
        wm.fileselect_add(self)
 
        return {'RUNNING_MODAL'}
 
def register():
    bpy.utils.register_class(ImportOperator)
 
def unregister():
    bpy.utils.unregister_class(ImportOperator)
 
 
if __name__ == "__main__":
    register()
    bpy.ops.object.import_aaigrid('INVOKE_DEFAULT')