kirra-docs

Surpac STR / DTM Import

Kirra reads Surpac string (.str) and DTM (.dtm) files three ways: string files as blast holes, string files as drawings, and a DTM with its string file as a surface. All three are on the Surpac row of the Import dialog’s Drawings / CAD tab.

Import dialog — Drawings / CAD tab, with the Surpac row's drop-down

How to import

Open the Import dialog and choose the Drawings / CAD tab — see The Import Dialog.

On the Surpac row, choose from the drop-down:

Choice	Reads	Creates
STR holes (default)	A `.str` of drill holes	Blast holes
STR	A `.str` of strings	Drawings (KAD lines, polygons and points)
DTM & STR	A `.dtm` and its `.str`	A surface

Click Open and select the file(s).

If the data is more than 100 km from what is already loaded, Kirra warns that the coordinate systems may not match — see The Import Dialog.

STR holes

Each hole in the string file is a collar point and a toe point. Surpac stores extra information about each point in its descriptor fields (D1, D2 …), and different sites put different things there — so Kirra asks what each one holds.

The STR Holes — map descriptor fields dialog lists every descriptor column with the first rows of the file. For each, choose what it is: Hole ID, Length, Diameter, Subdrill, Dip, Angle, Bearing, Burden, Spacing, Hole Type, or (Ignore).

STR Holes — map descriptor fields, with the Surpac 6.3 DrillBlast starter layout The Surpac 6.3 DrillBlast starter layout maps D3 to Hole ID, D4 to Length, D5 to Diameter and so on. Save your own mapping with the preset bar at the top.

Setting	What it does
Starter layout	Fill in the mapping from a common layout: Survey (10-field), Survey (5-field) or Surpac 6.3 DrillBlast
Diameter unit	Whether the diameter descriptor is in metres (×1000) or millimetres
Default Ø (mm)	The diameter for holes with no diameter descriptor

Click Import. The holes form one blast named after the file. If any land on top of existing holes, Kirra asks what to do with them. Kirra reports how many holes it imported.

STR (drawings)

Each string becomes a drawing entity:

A string whose first and last points match (within 1 mm) becomes a closed polygon.
Other strings become lines; single points become points.
The name comes from the first descriptor (D1, or D2 when D1 is empty). Unnamed strings are called Line_<string number>_0001.
The colour follows the Surpac string number.
Strings longer than 10,000 points are split into parts.

All of the file’s drawings go into one drawing layer named after the file. Text in the descriptors is kept as point labels; no separate text entities are made.

DTM & STR (surfaces)

A Surpac surface is two files:

File	Contains
`.str`	The points
`.dtm`	The triangles, by reference to those points

Select both together — hold Ctrl (Cmd on a Mac) and click each. With only one, Kirra reports Missing Files.

All the triangulations in the file are merged into one surface, drawn green with the default elevation colours, in a surface layer named after the .dtm. If the surface has more triangles than the 3D limit, Kirra offers to reduce it.

Coordinate order

Surpac writes coordinates as Northing (Y), Easting (X), Elevation (Z) — the reverse of the usual X, Y, Z. Kirra swaps them on import and export, so the data lands in the right place without you doing anything.

Kirra reads both text and binary .str files.

Drag and drop

You can drop Surpac files onto the canvas:

Dropped	Result
A `.dtm` and `.str` with the same name	Imported as a surface
A `.dtm` alone	Kirra asks for its companion `.str`
A `.str` alone	Kirra asks Surpac STR — holes or geometry? — choose Holes or Geometry

Surpac STR — holes or geometry?

A Micromine .str dropped on the canvas is recognised and imported as Micromine — see Other CAD Formats.

After import

A Surpac surface can be used for gradient colouring, boolean operations, assigning hole grades, contours, GeoTIFF export and blast analytics. See Importing Surfaces.

Exporting back to Surpac

In the Export dialog’s Surfaces / Mesh tab, click Save on the Surpac Surface (STR + DTM) row. One .str and .dtm pair is written for each visible surface.

Troubleshooting

Problem	Fix
Missing Files	Select both the `.dtm` and the `.str`
A dropped `.dtm` is not imported	Drop it together with its `.str`, both with the same name
Holes have the wrong diameter	Check Diameter unit in the descriptor mapping
The data lands in the wrong place	Check the file really is Surpac (Y, X, Z); a Micromine `.str` belongs on the Micromine STR row