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Clip (ArcGIS, QGIS, GRASS, Manifold; Extract Inside in TNTmips): The result includes the portions of polygons of one layer where they intersect the other layer. The outline is the same as the intersection, but the interior only includes the polygons of one layer rather than computing the LCGUs.
Clipping is defined as the interaction of subject and clip polygons. While clipping usually involves finding the intersections (regions of overlap) of subject and clip polygons, clipping algorithms can also be applied with other boolean clipping operations: difference, where the clipping polygons remove overlapping regions from the subject; union, where clipping returns the regions covered by ...
It can be used for line or line-segment clipping against a rectangular window, as well as against a convex polygon. The algorithm is based on classifying a vertex of the clipping window against a half-space given by a line p: ax + by + c = 0. The result of the classification determines the edges intersected by the line p. The algorithm is ...
Polygon: a region also includes an infinite number of points, so the vector model represents its boundary as a closed line (called a ring in OGC-SFA), allowing the software to interpolate the interior. GIS software distinguishes the interior and the exterior by requiring that the line be ordered counter-clockwise, so the interior is always on ...
Vector analysis is a primary function of MapInfo based on X, Y coordinates and the user can create and edit data directly with commands such as: node editing, combine, split, erase, buffer, clip region. MapInfo Pro includes a range of engineering “CAD like” drawing and editing tools such as lines, circles, and polygons (referred to as ...
In addition, many systems have tracing tools, so that newly digitized lines can exactly follow existing lines. During the overlay process, the preferred mode of sliver polygon prevention is the use of a fuzzy tolerance, which is sometimes called a "xy tolerance" (ArcGIS) or "snapping threshold" (GRASS), and was originally called an "epsilon ...
Cyrus–Beck is a general algorithm and can be used with a convex polygon clipping window, unlike Cohen-Sutherland, which can be used only on a rectangular clipping area. Here the parametric equation of a line in the view plane is p ( t ) = t p 1 + ( 1 − t ) p 0 {\displaystyle \mathbf {p} (t)=t\mathbf {p} _{1}+(1-t)\mathbf {p} _{0}} where 0 ...
Once all sides of the clip polygon have been processed, the final generated list of vertices defines a new single polygon that is entirely visible. Note that if the subject polygon was concave at vertices outside the clipping polygon, the new polygon may have coincident (i.e., overlapping) edges – this is acceptable for rendering, but not for ...