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Rotating of block model from one grid system to another grid system.

Kwamina AW 5 years ago in Resource Estimation updated 5 years ago 7

I am trying to rotate a block model from one grid system to a secondary grid system. I am finding it difficult to get the blocks line up well without overlaps though they are at the right position. 


How is this resolve in micromine.. 

Do you want to recalculate the coordinate system (planar to geographic) or just rotate the block model to any direction (X, Y, Z)?

Both grids are plane grids and I want to recalculate the coordinates and rotate such that the blocks line up well without overlaps.

+1

If I understand the question I think you want to go about it like this:


  • Rotate using Survey>Convert Coordinates Between>Plane Grid
  • If your coordinate transformation has rotation I think you will have to accommodate that in additional block rotation. I would suggest doing the grid conversion and measuring where the nodes align to check your work.
    • Note: I have have had trouble altering rotated block model files. From what I can tell MM really doesn't want you altering the XYZ data once you have applied a rotation. To get around this: first save a backup copy, do arith and multiple each xyz column by 1 and save to a new set of temp fields call east, north, elv (or whatever you like), be sure the structure is the same so there is no precision loss. Then modify the file and remove the XYZ fields this will kill the rotation. The temp field will save the original coordinate location.
  • Rename the _ columns to align with the names of your newly rotated grid columns. As you know MM always has to pair with block size for each row.
  • Next use Modelling>Block Model Tools>Converted Imported Data to Block Model. To apply simple rotation check apply rotation and rotate about the Z axis and place a 0 for the others. Ignore specify origin and parent block size. Also note the Modify input file does not actually work to you will have to create a new file.
Hopefully I didn't miss the mark too much on understanding your question.

Many thanks Geoff, I followed your guidance however the blocks are still overlapping. The blocks do not seem to rotate for some appropriately for some reason. I tried transforming and rotating some strings and they line up very well. I am not sure if I'm not doing something right. 

+1

Hi,  why not use the option Modelling | Block Model Tools | Reblock with rotation.  My understanding is that it is designed to do most of what you want.  Work out the angle between your current grid and your new grid.  Survey | Convert Coordinates Between | Plane Grids will tell you this if you do not know the rotation and you enter two common points.  Use that angle in the Reblock with rotation, keeping your blocks the same size and just rotating the blocks into a new block model.  Then use just block shift your new model (calculate the difference in east and north and if necessary z between two points in both grids and then use the File | Fields Calculate to add or subtract to your X,Y and Z values.  Your model should be on the new grid with the blocks rotated.

Thanks Keith

I tried this option however  I seem to hit a wall as this tool  requires I reblock. My current   block size is very small.(1.5X1.5X3). Not sure how to go around this. 

Hi  Geoff and Keith. I finally resolved the rotation issue thanks to you both. It was a hybrid solution . Basically I re-structured the file to disable the rotation per Geoff's suggestion and then rotated the block model using the Block model/Reblock with rotation functionality and then transformed the XYZ using the survey|convert coordinates.         


Once again many thanks to all of you.