Could anyone please explain in simple language what "surface tolerance" is regarding the transformer "Contour generator". What units are used? If I specify a surface tolerance of 1, which coordinates are filtered out?
Userlevel 5
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- Influencer
- 3345 replies
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22 May 2018
The way I understand it that tolerance is the minimum z-difference (in whatever units your data is in) needed for a point to be added to the surface model.
The below example may give you clear answer
- For example, if the elevation values in your input raster are in feet, but you want the contours to be generated based on units of meters, set the z-factor to 0.3048 (since 1 foot = 0.3048 meter).
- For another example, consider an input raster in WGS_84 geographic coordinates and elevation units of meters for which you want to generate contour lines every 100 feet with a base of 50 feet (so the contours will be 50 ft, 150 ft, 250 ft, and so on). To do this, set the contour_interval to 100, the base_contour to 50, and the z_factor to 3.2808 (since 1 meter = 3.2808 feet).
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