Many functions use the concept of filtering points. When performing an operation that goes through the database of DTM points and modifies them in some way, you can fine-tune the selection so certain points are used (those that pass the filter test) and certain points are ignored (those that fail the filter test).
You can filter points by specifying:
That the names of points are used to decide what passes and what fails.
That points belonging to only a specific surface pass.
That points with elevation above, below or between given values pass.
That points inside or outside a predefined fence area pass.
The summary page gives an overall indication of what the filter contains, without needing to go to each individual page.
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Option
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Description
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Reset button |
Click to reset the filter so all points will pass. |
Name filters are powerful. See the Name Filters section for more in-depth details on using wild cards for filtering names.
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Option
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Description |
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Names to pass |
Enter up to five names that should pass the filter. The standard entry of ALL (in uppercase) will pass all points. Blank entries are indicated by two consecutive hyphens i.e. --. |
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Names to avoid |
Enter up to five names that should fail the filter AFTER passing the pass filter. The standard entry of NONE (in uppercase) will pass all points. Blank entries are indicated by two consecutive hyphens i.e. --. |
The dropdown lists allow you to choose from names already existing in the DTM. See the Names List section for more details on the list.
Similar to name filters but searches on the tag of terrain points.
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Option
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Description |
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Tags to pass |
Enter up to five tags that should pass the filter. The standard entry of ALL (in uppercase) will pass all points. Blank entries are indicated by two consecutive hyphens i.e. --. |
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Tags to avoid |
Enter up to five tags that should fail the filter AFTER passing the pass filter. The standard entry of NONE (in uppercase) will pass all points. Blank entries are indicated by two consecutive hyphens i.e. --. |
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Option
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Description |
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Specific surface |
Select this checkbox and select the surface to which the filter should be applied. Only points on this surface will pass. |
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All selected surfaces |
Select this checkbox to have the filter applied to all visible and enabled surfaces. Points on disabled surfaces remain unchanged. |
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Option
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Description
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All |
This is the default option where point elevations are ignored, and all points will pass. |
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Above |
Select this option, and enter a value alongside it, to have all points with an elevation above or equal the value to pass. |
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Below |
Similar to the Above option, but this time to pass points below or equal a given value. |
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Between |
Select this option, and enter values alongside it, to have all points between a range, inclusive, to pass. The values can be the same to specify a single height. e.g. Entering values for between 0.0 and 0.0 will allow you to process only zero heighted points, useful for say batch deleting points that don't contribute to the ground model. |
These controls are only enabled if your project already contains predefined Fences. See Define Fence on how to do this.
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Option
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Description
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Fence |
Select this checkbox and specify the already predefined fence to which the filter should be applied. |
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Inside or outside |
Indicate whether points inside or outside the fenced area will pass. |