BLOCK MODEL
Overview You can open an existing block model or create a new block model with this function. In addition to opening existing Surpac *.MDL block models, you can also open Datamine and GEMS block models, as well as creating a new Surpac *.MDL model from Whittle *.MOD models and Whittle *.RES results files. Function Name(s) : • BLOCK MODEL OPEN From the Block modelling menu, select Block model, model, then New / Open to invoke the function.
Model name To create a new model, enter a name. When creating a new block model, the name should only consist of alphanumeric characters, and should start with an alpha character (a,b,c,...z). The name should not include spaces. Examples: mynewmodel, zone3west, testmodel_2008. To open an existing model, use the file chooser or type the name of the t he model, including the extension. The following model types are supported: *.DM
Datamine block model You can only open *.DM files with this function.
*.DMS
Extended Surpac block model An imported Datamine model with additional attributes created by Surpac - for example, calculated attributes.
*.BPR *.BPR
GEMS GEMS bloc block k mode modell (opt (optimi imised sed for horizo horizonta ntall need needlin lingg in in GEMS GEMS))
*.BPR2 *.BPR2
GEMS GEMS block block model model (opt (optimi imised sed for for verti vertical cal need needlin lingg in GEMS) GEMS)
*.FBM
Free Block Model This is an extended Surpac block model which allows free sub-blocking in X, Y, or Z. This format is usually created for the purpose of importing centroids from another source, such as Datamine or Vulcan, which have different sub-blocking than the Surpac *.MDL format. *.FBM files are created from Block model > Save as. as.
*.RES
Whittle results file
*.MOD
Whittle mo model fi file
*.MDL
Surpac block model This is the standard Surpac block model format.
Load With Constraints Constrained Model Name If the model is to be loaded with constraints select 'Y' and enter the name of the sub-model.
Overview
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BLOCK MODEL
Choose Cancel from the SELECT MODEL form to return to the previous menu. Complete the SELECT MODEL form and choose Apply. If the model exists and is not to be loaded with constraints, it will be made current and the BLOCK MODELLING menu is displayed. If the model is to be loaded with constraints, further forms are displayed to allow you to enter the constraints. See Loading Constrained Block Models for more detailed information about loading models with constraints. If the model does not exist, the CREATE DEFINITION FOR NEW BLOCK MODEL form is displayed so that you can confirm the creation of a new block model. CREATE DEFINITION FOR NEW BLOCK MODEL frm20020 Choose Cancel from the CREATE DEFINITION FOR NEW BLOCK MODEL form to enter a different block model name or choose Apply to display the CREATING NEW BLOCK MODEL DEFINITION form. CREATING NEW BLOCK MODEL DEFINITION frm20025 Model name The model name is for display only. Description Enter a description of the block model if desired. You may use this to record the purpose of the block model. Define Model using? The model may be defined using either minimum and maximum coordinates (the default) or using origin coordinates and extent. Using the radio buttons, it is possible to select which method is preferred. Choosing origin and extents will change the heading above the Minimum Coordinates boxes to Origin, and the Maximum Coordinates boxes to Extents. If any values were entered in these boxes, they will be recalculated to origin and extent values. Get Extents from string file? This option allows you to select a string file, and the extents of that string file will then be used to populate the Minimum Coordinates and Maximum Coordinates fields with values. Simply tick this field, and Location and ID Range fields will appear. Select the string file(s) you wish to use as the extents of your model, and then leave the fields. Once you leave the fields, the form will return to normal, and you will be able to modify the minimum and maximum coordinates of the model. Minimum Coordinates Enter the minimum coordinates of the block model, in Y, X, Z Cartesian coordinates. This is the lower front left hand corner of the volume to be modelled. Note that if the Origin/Extents radio button is selected, the value entered should be the block model origin, in X,Y and Z Cartesian coordinates. In most cases this will be the same as the minimum coordinates.
Overview
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BLOCK MODEL
Maximum Coordinates Enter the maximum coordinates of the total volume that is to be modelled. The point you enter here will be the upper, back, right corner of the volume being modelled. Note that if the Origin/Extents radio button is selected, the value entered should be the model extent in the X, Y and Z directions. The model extent is the distance from the model origin to the upper, back, right corner of the model. Note: Once the model has been created the minimum and maximum coordinates cannot be altered. If you need to model a different volume you must create a new model. Please note also that t he maximum coordinates may need to be slightly altered to accommodate the user block size you select. User Block Size Enter the block size for the Y, X and Z directions of the block. The unit block size is used as the reporting unit for block model reports. The block size determines the actual dimensions of the final modelled volume which can be greater than or equal to the specified extents. Note: The user block size cannot be altered after the model has been created. Model Rotation Enter the model rotation angles bearing, dip and plunge. These angles must be entered in degrees and define a rotation about the model origin. Note: The rotation angles of a model cannot be changed once the model is created. Sub Blocking Sub blocking is a method used by the Surpac block model to allow greater precision when applying geometric constraints (surfaces, solid models etc) to the model. Allowing sub blocking allows the model to divide a user block (defined above) into smaller blocks, which will then be used in calculations. See Sub Blocking for more information on the available sub blocking schemes. Once you have decided on a scheme, select "none", "standard" or "variable". Minimum Block Size The user block size (above) is used to perform all calculations, however, for precision, sub blocking may be used. Because sub blocking can create a very large number of blocks (and hence make the size of the model increase, and the speed decrease), the size of sub blocks should be chosen carefully. The minimum block size is some division of the user block size. Maintain Audit Trail The block model audit trail records all functions that modify the block model (for example fill functions) and can be used to re-create the block model if something goes wrong with the processing. See Audit Trail for more information. Choose Apply to display the MODEL CONFIRMATION form or Cancel to return to the SELECT BLOCK MODEL form. NOTE - The next form may take some time to appear. Please be patient. xxx frm20026
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BLOCK MODEL
The MODEL CONFIRMATION form shows the physical dimensions of the model and its blocks and subblocks. If these are acceptable, choose Apply to create the new block model. There is only one value that you can modify on this form, and it is the Possible Extents Adjustments It is often very difficult to determine the best extents for your data. Most people, when defining a block model, will simply choose the extents that suit the data, while giving no thought t o how these extents affect the model. It is therefore quite easy to get a very large number of blocks that lie on the outside of the model, but because of the size of the model, cannot be super-blocked to make the model more efficient. Because these blocks are on the edges of the model, they are very rarely filled with a value, and can dramatically affect the performance of the model throughout it's life (as a rule of thumb - more blocks = slower processing). These blocks will always be there, but they will never serve a substantial purpose. That is the purpose of this selection box. It lists a number of possibilities for the maximum coordinate of the model, and next to that it shows how many blocks will be created by the block model creation. Quite often, very small modifications of the model size will dramatically affect the number of of blocks that need to be created. So simply select the best option for you - one that does not greatly affect the model size (so that your data is not lost in huge amounts of waste) but does greatly affect the number of blocks created, and hence the performance of your model. In a worst case scenario, you have a user block size of 1x1x1, and you define the model to have extents of 511x511x511m. This will, at model create time, create about 800,000 blocks on the model boundary. By adjusting the extents 1m in each direction (to 512x512x512) you will create 1 block. This obviously will have a major effect on the performance of your model.
Loading Constrained Block Models Block models can be loaded with constraints to reduce the amount of information imported from the model files. See Block Model Concepts for a full description on the use of constrained block models. CONSTRAINING ATTRIBUTES BLOCK MODEL LOAD frm00907 Select Attributes to Import Lower Bound, Upper Bound, Import The scrolling region displays all the attributes in the block model and their types and default values. The Import field is used to indicate which attributes are to be included in the constrained sub-model. Numeric Attributes Attributes with numeric types (real, integer and float) can be bounded by an upper and lower numeric bound. Only blocks with attributes between these values will be imported. Enter the lower and upper bounds in the Lower Bound and Upper Bound columns. Blank entries indicate no bounds. String Attributes String attributes are bounded by supplying a list of valid character strings. Only blocks with string attributes with values matching those given will be imported. To define the valid strings for a character
Loading Constrained Block Models
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string attribute click the appropriate Edit String Bounds button. A new form will be displayed to enter the list of valid values for the attribute. EDITING STRING ATTRIBUTES STRING ATTRIBUTE LIST frm00908 Attribute name The name of the string attribute is displayed. Import all values? Enter 'Yes' if there should be no bounds on the possible values for the string attribute or 'No' to indicate that there are bounds on the attribute. If bounds are required enter the valid character strings in the scrolling region. ENTERING PHYSICAL CONSTRAINTS xxx frm20111 Enter the physical constraints required for loading the model. See Make Constraint for details on forming constraints. Note: Block constraints have no effect during block model loading. Bounds on block values should be entered on the previous form.
Loading Constrained Block Models
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