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General Considerations

1) Only rectangular borders are allowed. Call if you need an irregular border.

2) Limit model length and width to 1" increments.

3) Largest laser marked model size is 48" x 96" and 7" high relief.

4) Constrain your elevation grid height values (z values) to a valid range. Some data sets, such as the SRTM, have missing data.

    Missing data needs to be "repaired" or filled in as it is replaced with an out of range value such as -9999 or -32768.

    Out of range values may produce out of range height in the scaled model and are not allowed.

5) Bare earth elevation grids only. Buildings with vertical drops are possible but CNC milling tool limitations apply. Call.

6) Vertical exaggeration (if desired) is done by CNC printer setting, not by multipling elevation values by a scale factor in Global Mapper.

    Why? We have software tools that show if tool/object interfernce occurs when the vertical exaggeration is varied.

7) Image file size can be very large large at 500 pixels per inch. 

    For GeoTIFF image export, use the 'Grayscale - Min is Black' format (not 24-bit color) to minimize file size.

    Maxmum IMAGE file size as 48 x 96 x 500 x 500 bytes ... 1.152 Giga Bytes.

8) Review image and shape for irregularities. Correct irregularities before submitting.

    Check IMAGE for gaps in image, image rectification problems, image quality and resolution, alignment with elevation grid.

    Check SHAPE for gaps in data, missing data, data anomolies (spikes, lidar surface triangulation problems).

9) Import the final SHAPE and IMAGE files into Global Mapper. Verify their outlines coincide. Check meta data for file size consistency.

    Image file size height and width in pixels should be divisible by 100 with 0 remainder. Shape file height and width should be divisible

    by 100 with 1 remainder.

10) Keep in mind, changes in scale may have a large effect on volume of material. Increasing scale factor by 2, multiplies volume by 8.

11) The laser has excellent ability to transition across vertical drops. It does not mark vertical surfaces.

12) Verify or select suffiicient resolution of the image and shape source data for the scale of the model.



We review your SHAPE and IMAGE files to see if we can spot any problems before making the model.

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