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Sort objects into layers

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All "raw" vector objects generated by automatic tracing belong to the same layer. However, quite often there are objects of different vector layers on the same thematic layer. There are a number of techniques for the rapid separation of objects on the necessary layers

All "raw" vector objects generated by automatic tracing belong to the same layer. Generally, next steps are vector filtering (deletion of vector rubbish), line joining across gaps and autodetection of objects. The video "Automatic relief digitization in Easy Trace Pro" demonstrates the process.

It seems reasonable to attribute thick, dashed, and thin lines to different layers at once but this function is not provided in Easy Trace and for now we do not plan to add it because of two reasons

  1. First, it is difficult sometimes to tell a thick line from a thin one in real maps even by sight.
  2. Second, change of line type within one object may cause troubles at line form processing. For example, full-flowing and intermittent (hatch) segments of a river line should be smoothed together to avoid a jog at the change point. Besides, the point itself is always difficult to identify reliably - is it the hatch already or simply a gap in the line.

But anyway, objects should be attributed to layers.

Layer change actually consists of two operations - object selection + change of the current layer. There are some ways to speed up the process. Let us consider them by the example of relief contours

  1. Attribute all contours to the Intermediate Contours layer at automatic tracing. Most of isolines are of intermediate type and you will not have to change their layer;
  2. Switch off all layers but the target ones - Intermediate Contours, Index Contours, and Supplementary Contours;
  3. Select some index lines with Group Editor and press the key "S" (cyclic layer change). The current layer changes for Index Contours, and thus all the selected lines are attributed to it now.
  4. Unselection and selection of the next group of lines.
  5. The same for supplementary contours.

Contour attribution to different layers should be done after joining of line segments, filtering, and line form optimization of course, just before input of elevation values. It is convenient to set different colors and line width for lines belonging to the temporary layers Index Contours, and Supplementary Contours.

Don't try to make the lines looking "as in the map". For example it is better to use solid line type (or a hatch with very short gaps) for supplementary lines but to make them, say, crimson.

Line attribution to temporary layers simplifies both visual control and attribute data input. It is much easier to sort out the lines than to input attributes for every object individually.

This way of sorting out does for other objects. Remember that only visible and non-frozen layers participate in cyclic layer change (in the top-down order in the layer list).

Sometimes, it may be more convenient to apply object marking (for small objects for example)

  1. mark all the objects that should be attributed to different layers;
  2. start the Marked Object Indication view mode;
  3. press "F" (navigate to the next object);
  4. attribute the object (the hot key "S"), than "F" again (or "DEL" if it is rubbish).
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