File Information
ASCII Block Model File (Regular): BLOCK.ASC
ASCII File Format
Example
Corresponding Block Model Definition File
ASCII File Format
Block Centroid Block Variables
cx_1 cy_1 cz_1 var_1 var_2 Var_3... Var_N
cx_2 cy_2 cz_2 var_1 var_2 Var_3... Var_N
cx_3 cy_3 cz_3 var_1 var_2 Var_3... Var_N
.. ..
.. ..
.. ..
cx_N cy_N cz_N var_1 var_2 Var_3... Var_N
where
| cx_N cy_N, cz_N | Centroid of block N with respect to parent scheme. |
| var_N | Block variable. |
The centroid of blocks to be imported by Vulcan must be converted from absolute "real_world" coordinates to relative "parent scheme" coordinates.
To convert a centroid between coordinate systems, the following calculation may be used:
abs_x_centroid = (real_x_centroid-min_x_centroid)
+(x_size/2.0)
abs_y_centroid = (real_y_centroid-min_y_centroid)
+(y_size/2.0)
abs_z_centroid = (real_z_centroid-min_z_centroid)
+(z_size/2.0)
where
| x_size, y_size, z_size | Size of regular blocks in x, y, z. |
| min_x_centroid, min_y_centroid, min_z_centroid | Minimum centroid in block model file. |
| real_x_centroid, real_y_centroid, real_z_centroid | Block centroid from block model file in real-world coordinates. |
| abs_x_centroid, abs_y_centroid, abs_z_centroid | New block centroid in relative parent scheme coordinates. |
Thus, if the first few lines of an ASCII block model file initially looked like this:
Block Centroid Block Dimensions Block Variable
21806.25 11205.0 2105.0 7.5 10.0 10.0 0.0 00.0 30.0
21806.25 11215.0 2105.0 7.5 10.0 10.0 0.0 00.0 30.0
21813.75 11205.0 2105.0 7.5 10.0 10.0 0.0 00.0 30.0
and
min_x_centroid = 21738.75
min_y_centroid = 10655.0
min_z_centroid = 2105.00
and
xsize = 7.50
ysize = 10.0
zsize = 10.0
it would appear like this after the conversion:
Block Centroid Block Variables
71.25 555.00 5.00 0.0 0.0 30.0
71.25 565.00 5.00 0.0 0.0 30.0
78.75 555.00 5.00 0.0 0.0 30.0
The headers and field spacing are only included for clarity.
Currently, you must pre-process your ASCII block model file to suit the relative "parent scheme" format. This can be achieved by using a "gawk" script (refer to the GAWK manual in the System Administration > Effective AWK Programming section).
Example
(Regular ASCII Block Model in Parent Schema Relative Offset Format)
15.0000 5.0000 5.0000 2.930000 -99.000000
45.0000 5.0000 5.0000 2.930000 -99.000000
75.0000 5.0000 5.0000 2.930000 -99.000000
- - - - -
- - - - -
- - - - -
1395.0000 745.0000 685.0000 2.930000 -99.000000
Note:
To import Surpac block models, make sure that the Surpac ASCII file (.str) has no spaces in its name, for example, change pit model.str to pitmod.str. Also remove any header information from the .str file, any commas and the 1,1 (string name) from the first column. Also, Surpac exports coordinates in Y/X/Z format and this needs to be changed to X/Y/Z before the import. The number of decimal places in Surpac is often 12 and may be reduced prior to import. Columns in Surpac do not need to be a certain width, number or decimal places other than those restrictions placed by float or double integer restrictions.
Corresponding Block Model Definition File
* MAPTEK: Specifications 5-Jan-1999 13:35:02
BEGIN$DEF HEADER
n_variables=2.000
n_schemes=1.000
x_origin=77500.000
y_origin=3800.000
z_origin=400.000
plunge=0.000
dip=0.000
bearing=62.000
reblock
END$DEF HEADER
BEGIN$DEF VARIABLE_1
type='float'
name='sg'
default='2.93'
description='average sg'
END$DEF VARIABLE_1
BEGIN$DEF VARIABLE_2
type='float'
name='au'
default='-99.0'
description='average au'
END$DEF VARIABLE_2
BEGIN$DEF SCHEMA_1
desription='parent'
scheme_min_x=0.000
scheme_min_y=0.000
scheme_min_z=0.000
scheme_max_x=1410.000
scheme_max_y=750.000
scheme_max_z=900.000
block_min_x=30.000
block_min_y=10.000
block_min_z=10.000
block_max_x=0.000
block_max_y=0.000
block_max_z=0.000
END$DEF SCHEMA_1
BEGIN$DEF BOUNDARIES
n_boundaries=0.000
n_exceptions=0.000
n_limits=0.000
END$DEF BOUNDARIES
END$FILE
Note: The offsets in the .bdf file must line up with the sides of the blocks not the centres.
