int i;
	double rad_angle = 0.0;
	double angle = 0.0;
	double x = 0, y = 0, z = 0;
	double radius = 10.0;

	for(i=0; i<=36; i++)
	{
		// Transform degrees in rads
		rad_angle=(pi*angle)/180.0;
		// Calculate the x and z co-ordinates of a circle ground
		x = radius/(sqrt(1.0 + tan(rad_angle)*tan(rad_angle)));
		z = radius*(sqrt(1.0 - (1.0/(1.0 + tan(rad_angle)*tan(rad_angle)))));
		angle+= 10;

		// Check the co-ordinates in all the quadrants of the circle ground
		if ((i>=0) && (i<10)) // First quadrant
		{
			if (i==9)
			{
				_points[i] = TVector(0.0, 0.0, 1.0);
			}
			_points[i] = TVector(x, y, z);
		}
		if ((i>=10) && (i<19)) // Second quadrant
		{
			_points[i] = TVector(-x, y, z);
		}
		if ((i>=19) && (i<28)) // Third quadrant
		{
			if (i==27)
			{
				_points[i] = TVector(0.0, 0.0, -1.0);
			}
			_points[i] = TVector(-x, y, -z);
		}
		if ((i>=27) && (i<=36)) // Fourth quadrant
		{
			_points[i] = TVector(x, y, -z);
		}
	}
	// Construct the vector for the normal of the ground
	_normal = TVector(0.0, 1.0, 0.0);