You are here: Menu Commands > Block model > Constraints > New constraint file
GEOVIA Surpac

New constraint file

You can use this function to create constraints and save constraints files to use with other block modelling functions.

To run this function: Choose Block model > Constraints > New constraint file, or...

  • In the Function Chooser, type BM MAKE CONSTRAINT, and press ENTER.

It is easy to define simple constraints. However, you can also create complex constraint expressions if necessary.

CautionCaution: The constraint file saves the results of running a constraint. When you open the .con file, the same blocks will pass the constraint every time, even if their attribute values have changed. No additional blocks pass the constraint. The .con file is effectively a static list of blocks that passed the constraint at a specific date and time.

Fields on the Enter constraints form

Field Description
Constraint name

The letter associated with the constraint. This is the same as the position of the Constraint values table.

You can use these letters to create a constraint expression in the Constraint combination field. For example, you might create constraint a, of constraint type BLOCK, which is defined as grade > 0.2, and constraint b, of constraint type DTM, which is defined as above contact.dtm.

Constraint type

The type of constraint you want to apply. Options are:

  • CONSTRAINT: Blocks inside or outside of an existing constraint that is defined in a constraint file.
  • 3DM: Blocks inside or outside of one or more closed, valid objects.
  • BLOCK: Blocks with attribute values which match the expression that you specify.
  • Note: The BLOCK option is not available when you are creating a new block model by applying a constraint to an existing model (because you can use Lower and Upper in the Block model load form instead).

  • DTM: Blocks above or below a surface.
  • PLANE: Blocks above or below a plane defined by an equation.
  • STRING: Blocks inside or outside of closed segments of one or more strings.
  • X PLANE: Blocks greater than or less than a specified easting.
  • Y PLANE: Blocks greater than or less than a specified northing.
  • Z PLANE: Blocks greater than or less than a specified elevation.
Constraints file

The name and location of a constraint file that you have previously created and saved.

Note: This field is available only if you selected CONSTRAINT.

Inside
  • Selected: Blocks within the constraint file, 3DM, or string are selected.
  • Cleared: Blocks outside the constraint file, 3DM, or string are selected.

Note: This field is available only if you selected CONSTRAINT, 3DM, or STRING.

3DM file

The name and location of the 3DM file you want to use to constrain the block model.

The 3DM must also be consistent. That is, trisolations cannot intersect each other or define a common or touching surface.

Note: This field is available only if you selected 3DM.

Id range

The ID range for the 3DM.

Note: This field is available only if you selected 3DM.

Object range

The objects in the 3DM that you want to use to constrain the block model. If you leave this field blank, all objects are used. All objects that you specify must be closed and they must be set to solid or void.

Note: This field is available only if you selected 3DM.

Trisolation range

The trisolations of the objects in the 3DM that you want to use to constrain the block model. If you leave this field blank, all trisolations are used. All trisolations specified must be closed and be set to solid or void.

Note: This field is available only if you selected 3DM.

Attribute

The name of the attribute, for example grade. The values that you select in the Attribute, Operand, and Value fields collectively define the constraint.

Note: This field is available only if you selected BLOCK.

Operand

The operator to apply to the field. Options are:

  • = : equal to.
  • != : does not equal.
  • > : greater than.
  • <= : less than or equal to.
  • < : less than.
  • >= : greater than or equal to.

Note: This field is available only if you selected BLOCK.

Value

The value against which to perform the operand on the attribute value to constrain the block model.

Note: This field is available only if you selected BLOCK.

DTM file

The name and location of the DTM file that you want to use to constrain the block model. Only the blocks of the block model that are within the boundary string of the DTM are affected by the constraint.

Notes:

  • To use a DTM as a constraint, the DTM must be created by CREATE DTM.
  • This field is available only if you selected DTM.
Above
  • Selected: Blocks above the DTM, plane, X plane, Y plane, or Z plane are selected.
  • Cleared: Blocks below the DTM, plane, X plane, Y plane, or Z plane are selected.

For a DTM created on the XY plane, the portion of a block model that is considered above the DTM is the portion physically above the DTM.

For DTMs created on other planes, the portion of a block model that is considered above the DTM is the portion lying in the 'towards' direction of the plane (along the section's Z-axis away towards your viewpoint). For example, if a DTM was created using the active plane and the active plane was:

  • a vertical plane resulting from VERTICAL SECTION LOOKING EAST, then the 'towards' direction is to the West. The portion of the block model that is to the West of the DTM will be considered above the DTM .
  • a vertical plane resulting from VERTICAL SECTION LOOKING WEST, then the 'towards' direction is to the East. The portion of the block model that is to the East of the DTM will be considered above the DTM.
  • a vertical plane resulting from VERTICAL SECTION LOOKING NORTH, then the 'towards' direction is to the South. The portion of the block model that is to the South of the DTM will be considered above the DTM .
  • a vertical plane resulting from VERTICAL SECTION LOOKING SOUTH, then the 'towards' direction is to the North. The portion of the block model that is to the North of the DTM will be considered above the DTM.

Note: This field is available only if you selected DTM, PLANE, X PLANE, Y PLANE, and Z PLANE.

Object ID

The object number for the DTM that you want to use to constrain the block model. if you leave this field blank, the first object is used.

Note: This field is available only if you selected DTM.

Trisolation ID

The trisolation number for the DTM that you want to use to constrain the block model. If you leave this field blank, the first trisolation is used.

Note: This field is available only if you selected DTM.

Equation of plane

The equation of the plane used to constrain the block model.

Note: This field is available only if you selected PLANE.

String file

The name and location of the string file that you want to use to constrain the block model.

Note: This field is available only if you selected STRING.

ID range

The ID range of the string file.

Note: This field is available only if you selected STRING.

Extent

The direction in which to extend the string file. Options are; X, Y, and Z.

Note: This field is available only if you selected STRING.

Lower bound

The lower extent to extend the string file. If you leave this field blank, the coordinates of the minimum point of the block model, in the direction specified, are used.

Note: This field is available only if you selected STRING.

Upper bound

The upper extent to extend the string file. If you leave this field blank, the coordinates of the maximum point of the block model, in the direction specified, are used.

Note: This field is available only if you selected STRING.

String range

The range of strings in the string file that you want to use to constrain the block model. If you leave this field blank, all strings are used. All strings must be closed.

Note: This field is available only if you selected STRING.

Segment range

The range of segments in the string file that you want to use to constrain the block model. If you leave this field blank, all segments are used. All segments must be closed.

Note: This field is available only if you selected STRING.

X

This specification is for a plane normal to the X axis and is defined by the x coordinate of the plane.

Note: This field is available only if you selected X PLANE.

Y

This specification is for a plane normal to the Y axis and is defined by the y coordinate of the plane.

Note: This field is available only if you selected X PLANE.

Z

This specification is for a plane normal to the Z axis and is defined by the z coordinate of the plane.

Note: This field is available only if you selected X PLANE.

Add Add the constraint to the Constraint values table.
Clear Remove a constraint from the Constraint values table.
Start again Remove all constraints from the Constraint values table.
Constraint values The list of constraint expressions that you want to apply to the block model. Each row is one expression.
Keep blocks partially in the constraint
  • Selected: Blocks that have any part assessed as being in the constraint are kept.
  • Cleared: Only blocks that have a centroid that meets the criteria of the constraints are kept.

CautionCaution: If you keep blocks partially in the constraint and use the block model report, without using a volume adjustment factor, you will overestimate your resource.

Note: The Keep blocks partially in the constraint option is not available when you are creating a new block model by applying a constraint to an existing model.

Constraint combination

The boolean expression you use to combine the constraints that appear in the Constraint values table. The two boolean operators you can use are AND and OR. You identify the constraints to combine using the letter it is assigned in the Constraint name, for example, a AND b. Another example is a OR b OR c.

If you leave Constraint combination empty, all constraints are combined using the AND operator.

Save constraint to

The name and location of the file to save the constraints you have set up. If you ran the New constraint file command or you want to save the constraints to a file, you must specify a file name. The constraints file effectively contains a list of blocks that matched the constraint at the time when you created the constraint.

Output

The constraint file is created with the file name you specified.

Troubleshooting

Messages Description
Model ''name'' is not registered with the current model. You can apply constraints models only to block models whose geometry (extents and resolution) are identical.