Self-accomplishment of GIS mapping staff (2)--Cartographic consciousness

Self-accomplishment of GIS mapping staff (2)--Cartographic consciousness

by Li Yuanxiang

The last mention of some cartographic errors of GIS mapping personnel, mainly for the GIS cartographic staff to analyze some of the problems in the cartographic work. But how to improve the self-cultivation of cartography, but it is a very long process, this chapter mainly for the promotion of cartographic cultivation to make some theoretical groundwork. One of the most important things to emphasize is cartographic awareness.

What is cartographic awareness? is when the first time to see the data, immediately respond to the data, basically forming a preliminary mapping ideas, and determine the technical route of cartography. In the final analysis, the so-called cartographic consciousness, for the drawing industry of the veteran, is experience. But experience often takes a long time to accumulate. There is also the case that a person with a talent for cartography is born with this keen sense of touch. But in any case, consciousness is illusory and needs to be cultivated for a long time. Let's talk about what GIS mapping consciousness includes.

Consciousness 1: The concept of a layer

Whether using GIS mapping or traditional image processing tools for cartography, the technology community has almost always organized graphs in layers. Why is there such an agreement? Let's analyze what the layer contains. In GIS, many key technologies involve layers, such as symbol layer, layer, data layer, MAP element layer and so on.

First, the layer is a classification method. Almost every GIS software will be very explicit requirements and restrictions on the layer, the data storage and organization are implemented in layers, and its rules are much stricter than CAD, so many people feel more confused about GIS mapping. A professor at a university in the last few days asked me that her students liked to use CAD to draw, and she couldn't understand why they liked CAD better. I told her at the very basic point, the CAD is drawn out is the figure, and the GIS is to draw the data, but also need to map the data. Of course, the two tools are different in many places, but for the drawing, the difference as I said, GIS will be relatively cumbersome and complex, do not want to CAD so free. But it is the GIS has other unique advantages of CAD completely does not have, so there are very many people to the GIS data to be plotted, do a good job of the front-end display part. GIS uses its layer of data classification, in fact, it is very convenient for later calculation and processing, more normative role.

Secondly, the layer has the position characteristic, namely upper gland lower layer. In cartography, very many people hate this natural logic, because it is a very painful task to handle the gland. But in fact, it is this gland relationship that makes GIS map making easy. For example, the two-line symbol setting, you can see the nature of the two-line symbol is two with a certain line width of the line symbol layer overlay each other, the upper cover of the lower layer, so that it will appear to have the same edge as the symbol.

There are also examples of previous road edges, as well as the use of a layer of the gland relationship, but this relationship is the same data using two layers to render it.

Layer of the gland example is simply a number, including the use of masks and other ways is also a very good way to use the gland. Therefore, do not think that the gland is a bad thing, in the eyes of professional-level cartographic personnel, the gland is a natural available rules. Without this awareness, you might miss out on a lot of cartographic shortcuts.

Finally, the layers are stackable. The superimposed nature is the most used, regardless of the acceptance, even if it is unconscious to the mapping, will also use the layer overlay. For example, the most basic to put a few data on the same map, this becomes the graph stack added. Of course, experienced drafters will also tell us that there are a lot of stacking methods that can be done with almost unimaginable results. For example, the stacking of symbolic layers, stacking beautiful symbols

As if using overlay shadow data and transparency to achieve emboss effect

or overlay and work with a cartographic layer to make the map look more stereoscopic.

None of this is done with the related characteristics of the layer. Interestingly, almost all the features of the map, will skillfully use the characteristics of the layer to make a fuss, and the characteristics of the layer to the fullest. So, why am I here to first raise the concept of the layer, because this is the basis of GIS mapping, and it is not a GIS can be very good, it is not a technical term, but a basic noun, with the organization, gland, superposition and other basic attributes of the noun.

Awareness 2: Data Awareness

Why do you want to mention data? Since GIS mapping is a mapping of data, there is hardly a cartographic person starting with the vectorization of the data, because we will get the data before we go to the drawing, rather than drawing it directly like CAD. Well, the problem is coming soon. If you get the data to map directly, there will be a lot of problems. Some people complain that the quality of the data is too poor to make maps based on data, others say that the data is too small, the map is vague and seems to lack content. For many years, this "kind" approach by cartographic staff was rather unwise. Although data is the foundation of cartography, it is not always possible to limit the mapping of the map to data. For example, in the production section of the vegetation, the ArcGIS Cartographic Techniques Series (1) To restore the true vegetation, it is a practice to improve data quality by using vegetation polygons to generate a scrub effect on the surface of a random point.

As mentioned above, the way the terrain is rendered, "ArcGIS Cartographic Technique Series (2) Terrain rendering", using the original data to do simple processing and stacking, you can restore the high and low terrain.

Others, of course, need to do some processing of the data themselves and retouch the map by processing some of the ancillary data. For example, by computing the projection surface of the polygon data, the projection surface is superimposed to make the building look more stereoscopic (the Internet map is doing so).

For the use and processing of data, its key is from scratch, from there to excellent. In addition, there is no esoteric approach. However, it is possible to improve the quality of the map by means of data processing, which is an integrated capability that requires a combination of skills and skills, which is difficult for the general cartographic staff.

Consciousness 3: Thinking and observing

Thinking and observing is the most difficult to cultivate a cartographic consciousness. This is not to say that the cartographic staff for cartography lack of thinking and observation, here is to express a deeper way of thinking, can be understood as the need for a sharp mapping of the olfactory, and through effective observation and thinking, to achieve the seemingly impossible map effect. For example, the effect of the water cube mentioned in the previous section is to simulate by observing the texture of the water cube surface, and to use the luminous effect of the representation, such as

There is the use of Hillshade can achieve the three-dimensional effect of the unspoken rules, clever use of internal buffer and Euclidean distance to generate raster data, the ultimate relief effect, specific reference to the "ArcGIS Mapping Skills Series (3)-Make the map more stereoscopic"

All of these need a lot of observation, thinking, analogy, and so on, all from the sharp observation of the data, that is, I in front of the data awareness based on the realization.

Awareness 4: Ingenious use of tools

Why use it skillfully, rather than using it skillfully? There is an essential difference. Perhaps everyone has heard the story of selling oil Lang, the most familiar word is "without him, hand ripe ear." Only on the basis of proficiency in the tools, we will think how to skillfully use them. For example, using the Point tool to generate random vegetation points to fill, the above mentioned is the inner buffer, Euclidean distance, cropping, hillshade and overlay to achieve the three-dimensional relief effect. These are the way of surprise, there is no rule of drawing can not use European geometry tools, the key is how to use. The effect of the map is perfect, the key is to see whether the tool uses the beauty.

Summarize:

With regard to cartographic consciousness, it has always been a great length of indoctrination that it is important to practice more thinking, to accumulate in practice, and to integrate into the consciousness of cartographic personnel. In this way, the cartographic consciousness will inadvertently play its part in the map making.

Self-accomplishment of GIS mapping staff (2)--Cartographic awareness