Command Help create-isosurfaces

 

Command Name	Menu	Quick Key	Link to Command Table
create-isosurfaces	Model ribbon | Data from Model | Isosurfaces Surfaces ribbon | Create | Isosurfaces	iso	Click here

 

• Description

• How to Use

• Example

Description

Create a wireframe isosurface(s) from defined values within a block model.

 

 

How to Use

1. Ensure at least one block model object exists in memory.

2. Run this command.

3. The Generate Isosurfaces dialog is displayed.

4. Select the output  wireframes object in which the isosurfaces will be saved.

5. Select the Input Block Model which is to be used in generating the isosurfaces.

6. Optionally select a Subsample value.

7. Select the Isolevels Column.

8. Define the Isolevel Type parameters.

9. Define the Absent cells/values parameters.

10. Optionally select Smoothing parameters.

11. Select the an Isolevel ValuesFrom option.

12. Click Add to add the values to the Current Values list.

13. Select OK to generate the isosurface(s).

14. Load the isosurface(s) into the data window and check against the original block model data.

Examples

In the following example, isosurfaces were generated for a model according to data held in a user-defined "S" field. 2 unique values could be found in the data set; 2 and 4. By setting the Isolevels Column to [S] and the Isolevel Type to Passing Value(s), the surfaces were generated shown as below:



Note how the blue area (representing S = 2) encapsulates the smaller purple area (where S = 4). This is because in the blue area, 2 is the trigger point at which data values are included, up to the maximum value (2, 2.1, 2.7, 2.8, 3.4, 4.0, 4.2 etc., for example) and 4 represents a subset of this (e.g. 4.0, 4.2 etc.)

 

In the following example, the block model stores different ROCK type classifications for each block, ranging from ID 2 to ID 4. These have then been converted into isoshells:



These surfaces were generated by selecting the Equal to Value(s) option and the ROCK Isolevels Column. The blue and green areas represent data where the ROCK value exactly matches the value 2, 3 or 4 - all other values are ignored. As such, the data areas are distinct.

 

The surface of a Passing Values(s) isosurface (as shown in the examples above) will not necessarily follow cell boundaries, as it uses interpolation between samples to determine the point at which the level was crossed. This means that every sample must have a valid numerical value. Absent cell values or missing cells are tagged with a special value which does not necessarily have a numeric equivalent. This is normally treated as being very low. However, depending on the particular task, it may be necessary to treat absent values as being very high, in order to generate an isosurface in the correct direction, as shown in the examples below.

The following example shows a simple isosurface that has been created within the extents of the block model on the surface of the topology, since no cells were present in the empty region:



Repeating the above example, but including boundaries, means that not only were the missing cells in the air above the surface checked, but the ‘missing’ cells outside of the model boundary were also considered: