Build Steps

Steps are the fundamental building blocks of mine geometry models. Each step represents a discrete volume of excavation at a specific point in time with defined attributes.

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To generate a single or multiple (batch) step(s), there are three main steps:

1) Associate the mining date to the survey

• For the "single step", the date is manually entered to each step
• For the "batch generation steps", the date is automatically pull from elsewhere. Refer to the batch generate steps page to learn more.

2) Set the attributes of each steps

• Resolution - Determines the dimensions of the blocks used to construct the geometry mode
• Type - Classification of the excavation (e.g., Development, Stope, Caving)
• Material - Material classification (e.g., Void, Backfill, Ore)

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Resolution

Available resolutions include:

Resolution	Use Case	Performance
1m	High detail for mXrap analysis	Slower
2m	Balanced detail and performance	Moderate
3m	Good for larger excavations	Faster
5m	Whole-mine models, numerical modelling	Fastest

The resolution affects both processing speed and volume accuracy. Smaller resolutions provide more accurate volumes but take longer to process. The model will slightly overestimate volume by an amount proportional to the resolution used.

Best practice

• Start with 2m resolution for general mXrap usage
• Use 1m resolution only when high detail is critical
• Increase to 3-5m for whole-mine models or numerical modelling
• Consider processing time vs. accuracy requirements

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The date, type, and material attributes significantly affect the final model results. Ensure these are set correctly for each step to achieve accurate time-varying geometry, because it affets the intersection handling

Intersection Handling

There are two types of intersection calculations:

Same Type and Material

When two steps have the same type and material (e.g., both are Caving/Void):

• The second date's shell is added to the first
• Only the volume relevant to the second date is saved
• This represents expansion of the same excavation type

Different Type or Material

When steps have different types or materials (e.g., Development vs Stope):

• The intersection volume changes from one type to another
• For example, development that becomes a stope
• The overlapping volume is converted rather than added

3) Create the Steps (to use it to build the model afterwards)

Best practice

• Set accurate mining dates for proper chronological ordering
• Use consistent Type and Material classifications across all steps
• Add descriptive comments to steps for future reference
• Review step attributes before building models

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Below are info related to the step and the full procedure to manually build a step

Bounding Box Generation

When you select a survey, the app automatically generates:

1. Survey outline - The original survey geometry (purple wireframe)
2. Bounding box - Automatic bounds around the survey (adjustable thickness)
3. Excavation boundary - The block volume that will be saved as the step

You can override the automatic bounding box if needed to clip specific portions of the survey. However, use this feature carefully - clipping a survey without maintaining a closed surface will result in an incomplete volume.

Block Face Generation

The step building process occurs in two stages:

1. Block Faces - Generates the external boundary blocks (typically the longest step)
2. Filling - Fills the interior of the boundary blocks using a specialised algorithm (usually fast)

Development geometry blocks

The image above shows how development surveys are converted into block geometry. The app processes the survey to create blocks that represent the excavation volume.

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Closed Surfaces Required Input surveys must be closed surfaces with no large gaps. If the survey has missing sections (e.g., a cave shape with the bottom completely missing), the app will only create a shell rather than a proper volume, which will not work correctly in model building.

There is an automatic hole-patching option which can solve certain kinds of holes.

Viewing Options

Use the viewing controls to inspect your step before saving:

• Toggle between survey outline, bounding box, and excavation boundary
• Adjust bounding box line thickness for better visibility
• Use wireframe mode to see the relationship between the original survey and the block volume
• Enable clipping planes to inspect internal structure

Video

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Note that this video was made before the batch generate steps options was built.

Use the automatic boundary box on closed surveys to construct outer blocks and internal blocks. Also assign attributes for model generation.

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Troubleshooting

Problem: Step generation fails or produces unexpected results

• Verify the input survey is a closed surface
• Check for large gaps or missing sections in the survey
• Ensure the survey has sufficient detail for the selected resolution
• Try increasing the resolution if the survey is very detailed

Problem: Processing takes too long

• Increase the resolution (larger blocks = faster processing)
• Reduce the survey complexity if possible
• Process smaller sections separately if needed