Polygonal Estimation

Polygonal estimation (Voronoi prism estimation) is a simple and fast way to build local influence volumes from composites. The method partitions a section into cells where each area is controlled by the nearest composite, then converts those cells into prisms for reporting and estimation workflows.

What this method does

• Uses the currently selected composite set as control points.
• Uses the selected prism section/orientation to build Voronoi cells.
• Converts each cell into a prism.
• Clips the generated prisms to the selected prism limits.

This makes the selected prism the final estimation boundary.

Before you start

Prepare data in this order:

1. Create a section that represents your estimation view (longitudinal or plan view).
2. Create mineralized intervals.
3. Create composites from those intervals (commonly central composites).
4. project composites to the working section and save them as a dedicated composite set. This will create a thickness value for all composites, needed for the polygonal estimation
5. Create a prism that covers the full area and thickness to estimate.

Important:

• Composite points outside the prism volume are not kept in the final Voronoi result.
• If you want horizontal polygons, use an appropriate plan-view section.

Recommended prism calculation setting

Before generating Voronoi prisms, verify the prism calculation mode:

• Open the Prism manager.
• Go to Calculation > Calculation Settings.
• Select By Composites.

This keeps prism values aligned with composite-driven estimation.

Create Voronoi prisms

1. Select the prism that defines your estimation boundary.
2. Right-click the prism.
3. Choose Create Voronoi prisms.
4. In the prompt, enter Maximum size for each polygon.

Command/prompt reference

• Create Voronoi prisms: Generates Voronoi-based prisms from the active composite set and the selected prism context.
• Maximum size for each polygon: Limits the extent of each Voronoi cell around its composite, helping prevent overly large polygons in sparse areas.

Results in the Prism list

After processing:

• A Voronoi subfolder is created under the selected prism path (name prefix: Voronoi_).
• Generated prisms inside this folder are the final clipped Voronoi prisms.
• Temporary construction prisms are removed automatically.

You can then select these prisms in the Prism dialog list and run your usual reports.

Practical guidance

• Use a prism thickness large enough to include all composites you want considered.
• Generated Voronoi prism thickness uses composite thickness when available; otherwise, the selected prism thickness is used.
• Choose polygon maximum size based on drill spacing and confidence level:
  • Smaller value: more local control.
  • Larger value: broader influence.
• If Voronoi limits look too wide or too tight, regenerate with a different maximum size.

Legacy figure references

• Figure 62: Voronoi prisms concept.
• Figure 63 (left): Prism limiting Voronoi extents.
• Figure 63 (right): Voronoi prisms after creation.