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Description: Terrain - third party format | Version: 9.0.0 | Updated: 01.01.13 | |
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Some terrain data formats of third party software can be converted to the WindSim .gws format. As guidance, key data interpreted by WindSim found in third party formats are reproduced below. Both data organised as contour lines and in a regular grid can be converted. Be aware that the data must be in total compliance with the below examples for a successful conversions. If you experience any problems using the conversion tools, please send your format to WindSim AS, as the Tools->Convert terrain model will be in continuous development.
The conversion from contours to a regular grid is based on linear interpolation of the contours nodes located nearest to the nodes of the regular grid. If the differences in distance between adjacent nodes forming the contour lines become too large, the conversion method could be inaccurate. A refinement of the contour lines is automatically suggested if the distance between contour nodes become too large.
The WAsP .map format starts with 4 header lines, where only the fourth line is interpreted by the conversion tool. The fourth line contains the scaling and offset factors z_scale and z_offset. If these values are set different from 1.0 and 0.0 respectively, then the following heights will be established in WindSim; z_windsim = z_scale*(z_offset + z_map).
The following lines contain the contour data. If a line starts with a real (Z) and an integer (N), then the integer gives the number of following pairs of east-west and north-south coordinates with a height given as the real Z. If a line starts with two real numbers (R1) and (R2) and then an integer (N), then the integer gives the number of following pairs of east-west and north-south coordinates with a roughness height given by the real numbers R1 and R2 as the right and left hand side values respectively. Each record with contour data could be given with single pairs or as three pairs on each record. The below .map example shows three pairs per record:
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+DEMO|UnKn (Unknown datum)
0.0 0.0 0.0 0.0
1.0 0.0 1.0 0.0
1.0 0.0
830.0 16
166894.0 5703949.0 166906.0 5703950.0 166920.0 5703951.0
166934.0 5703950.0 166949.0 5703939.0 166951.0 5703915.0
166936.0 5703899.0 166924.0 5703893.0 166910.0 5703890.0
166897.0 5703890.0 166884.0 5703893.0 166871.0 5703899.0
166858.0 5703915.0 166862.0 5703938.0 166882.0 5703947.0
166894.0 5703949.0
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0.5000 0.0300 27
159036.9 5705728.0 159116.0 5705761.0 159148.9 5705741.5
159188.5 5705603.0 159293.9 5705504.5 159366.4 5705392.5
159478.5 5705445.0 159630.1 5705478.0 159676.3 5705596.5
159722.4 5705741.5 159801.5 5705833.5 159841.1 5705880.0
159893.8 5705965.5 159906.9 5705998.5 159972.9 5706024.5
160071.8 5706057.5 160229.9 5706057.5 160236.5 5706057.5
160243.1 5705886.5 160210.1 5705761.0 160196.9 5705695.5
160098.1 5705550.5 160104.7 5705544.0 160117.9 5705484.5
160183.8 5705247.5 160190.4 5705063.0 160198.5 5705040.5
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The AutoCAD .dxf and .dwg formats containing contours must be filtered in order to only contain the contour line data before converting the data to the .gws format. The filtering can be done with the freeware Dxf2xyz available at http://www.guthcad.com.au Extract from filtered .xyz file:
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1423867.259069,4893089.049024,780.000000 1423865.991614,4893066.028702,780.000000 1423860.985547,4893051.592401,780.000000 1423855.974078,4893038.853271,780.000000 1423848.397813,4893033.643849,780.000000 1423838.682060,4893033.080448,780.000000 1423828.944912,4893032.627098,780.000000 1423829.030462,4893009.063536,780.000000 1423826.965463,4892994.864576,780.000000 1420368.647705,4893108.244240,640.000000 1420373.963842,4893108.971279,640.000000 1420440.207429,4893109.737264,640.000000 1420478.365962,4893115.274838,640.000000 1420607.657164,4893172.829613,640.000000 . . . |
The ESRI Shapefile .shp format containing contours must be filtered in order to only contain the contour line data before converting the data to the .gws format. The filtering can be done with the program Arcv2CAD converting .shp files into .dxf files. As a second step the .dxf must be converted to .gws as described above. The program Arcv2CAD is available at http://www.guthcad.com.au
The Surfer .grd format start with header information, giving number of nodes and extensions. Then follows the height data organised in a regular grid, starting at the Southwest corner proceeding towards East (nxp) and then towards North (nyp), with a blank line whenever nyp is augmented. Ten height values are stored in each record as real numbers, see below sample:
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! comments not belonging to the format DSAA ! header 25 30 ! nxp nyp; # nodes in West-East and South-North direction 0 900 ! x_min x_max; Extension in West-East direction 0 700 ! y_min y_max; Extension in South-North direction 25.0 150.0 ! z_min z_max; Extension in vertical direction z1_1 z2_1 ......... z10_1 ! z values starting in South-West corner, z11_1 ............... z20_1 ! progressing towards East and North z21_1 ..... z25_1 z1_2 z2_2 ......... z10_2 z11_2 ............... z20_2 z21_2 ..... z25_2 . . . z1_30 z2_30 ....... z10_30 z11_30 ............. z20_30 z21_30 .... z25_30 |
The WAsP .rsf format start with header information, giving number of nodes and extensions. Then follows the height data organised in a regular grid, starting at the Southwest corner proceeding towards East (nxp) and then towards North (nyp). WindSim only interpret the first three columns with terrain data and skip the remaining columns with WAsP results. The first three columns must contain three integers, or three reals, a mixture of integers and reals will give a conversion failure.
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! comments not belonging to the format 20 15 ..... ! nxp nyp; # nodes in West-East and South-North direction ..... x1_1 y1_1 z1_1 ..... ! x,y,z values starting in South-West corner, x2_1 y1_1 z2_1 ..... ! progressing towards East (nxp) and North (nyp) x3_1 y1_1 z3_1 ..... . . . ..... . . . ..... x20_1 y1_1 z20_1 ..... x1_2 y1_2 z1_2 ..... x2_2 y1_2 z2_2 ..... x3_2 y1_2 z3_3 ..... . . . ..... . . . ..... . . . ..... . . . ..... x20_14 y1_14 z20_14 ..... x1_15 y1_15 z1_15 ..... x2_15 y1_15 z2_15 ..... x3_15 y1_15 z3_15 ..... . . . ..... . . . ..... x20_15 y1_15 z20_15 ..... |
A generic xyz format is provided, consisting of 3 or 4 columns, where the first three columns give the position of nodes in East-West, North-South and vertical direction. If the fourth column is present the values are interpreted as roughness heights. The values in the columns can be given as either integers or reals. The storing order of the nodes can be of the following four types:
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Type 1 Type 2 Type 3 Type 4 ------------------- ------------------- ------------------- ------------------- | nyp*nxp| |1 2 3 ....... nxp| |nyp 2*nyp nxp*nyp| |1 nyp+1 | | | |nxp+1 2*nxp| |. | |2 | | | | | |. | |3 | | | | | |. | |. | | | | | |. | |. | | | | | |. | |. | | | | | |3 | |. | |nxp+1 2*nxp| | | |2 | |. | |1 2 3 ....... nxp| | nyp*nxp| |1 nyp+1 | |nyp 2*nyp nxp*nyp| ------------------- ------------------- ------------------- ------------------- |
Independent of the original storing order the converted .gws format will be of type 1.
The storing type is determined automatically based on the file structure. Hence, either the first or second column must contain equal numbers in the first two rows, see below sample extract of a valid xyz file:
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! comments not belonging to the format 649000 4332300 840 0.05 ! xyz format of type 1. 649050 4332300 840 0.05 ! the fourth column is optional, 649100 4332300 840 0.05 ! if included it will be interpreted 649150 4332300 840 0.05 ! as a roughness height 649200 4332300 840 0.05 649250 4332300 840 0.05 649300 4332300 840 0.05 649350 4332300 840 0.05 649400 4332300 840 0.05 649450 4332300 840 0.05 649500 4332300 840 0.05 649000 4332350 839 0.05 649050 4332350 840 0.05 649100 4332350 840 0.05 649150 4332350 840 0.05 649200 4332350 840 0.05 649250 4332350 840 0.05 649300 4332350 840 0.05 649350 4332350 840 0.05 649400 4332350 840 0.05 649450 4332350 840 0.05 649500 4332350 840 0.05 . . . |