Drawings Examples


Example: Draw Lines, Areas and Points

Simple example of using basic mouse moves to add points, lines and areas to a drawing.

Example: Drawings use Geom Fields in Tables

An essential discussion on how drawings are created from geom fields in tables, including how the drawing knows which coordinate system to use.

Example: Two Drawings from the Same Table

Take a table with a geom field that is visualized by a drawing.  Add a second geom field to the table and create an rtree index on that field so it can be visualized by a drawing.   Copy the first drawing, paste it and adjust the pasted copy so it uses the second geom field. Demonstrate how to use the Transform dialog to show "live" modifications in the second drawing compared to the first drawing.

Example: Create a Drawing from a Geocoded Table

A partner example to Example: Create a Geocoded Table from a Drawing   A geocoded table has records with a latitude and longitude for each record.   This example starts with a table containing a list of cities with a latitude and longitude field for the location of each city.   We create a geom from the latitude and longitude fields using a template in the Transform dialog and then we create a drawing that shows the cities as points.  This example shows all the infrastructure steps involved.

Example: Format a Drawing using the Style Dialog

In this example we provide a first, step by step look at how to format areas in a drawing using the Style dialog.  We can specify the same formatting for all areas or use a field to automatically set formatting, a process usually known as thematic formatting.

Example: Format the Size of City Points by Population

A common GIS task is to format the size of points in a drawing based on some value.  For example, the size of points that represent cities might be formatted based on the value of the city's population, with cities that have larger populations being marked by larger point icons.  This is an example of thematic formatting and is easy to do using the Style dialog.

Example: Add, Delete and Edit Thematic Formatting Intervals

This topic provides a step by step example of adding, deleting and editing intervals in the Style dialog that are used for thematic formatting.

Example: Multiple Primary and Fill Colors in a Drawing

At first glance that the same Color and Color, Fill values apply to areas, lines and points in a drawing may seem a limitation.   It is easy to use different Color and Color, Fill settings for different objects with different colors for areas, for lines and for points.   This example shows the simple procedure to use.

Example: Style Properties in the mfd_meta Table

Style properties for drawings such as colors for areas are stored in human readable JSON values as properties in the mfd_meta system table.   This example shows how we can copy formatting from one drawing to another by simply copying values between records in the mfd_meta table.

Example: Formatting Tricks

The visualization capabilities of Manifold using Style can be exploited to provide many visual effects.   This topic provides some examples of how to use Style in unexpected ways to create a range of more elaborate effects.

Example: How Not to Format a Drawing

When using Style to format a drawing it is a really bad idea to use the same color for objects that is used for the background color.    It can also be a bad idea to use transparent color.   This topic illustrates why.

Example: Trace an Area in a Map over an Image Background

In a map with a drawing layer above an image layer (served dynamically by an imageserver), create an area object in the drawing by tracing over the outlines of something seen in the image layer below

Example: Create a Line using the New Object Dialog

Step by step creation of a line in a drawing using the New Object Dialog.

Example: Create a Line using Curved Segments

Creating a line made up from curvilinear geometry using the New Object Dialog.

Example: Create an Area with a Hole

Using the New Object Dialog, create an area in a drawing where the area includes one or more holes.  This is similar to how we create areas that have islands as part of the area.   

Example: Create an Area with Holes and Islands

Using the New Object Dialog, create an area in a drawing where the area includes holes and also islands.

Example: Create a Multipoint

How to create multipoints using the New Object Dialog.  This topic provides two examples:  First we create a multipoint and then next we create a multipoint having two branches.  The purpose of this topic is to help teach the implementation of geometry in Manifold and other typical spatial packages using a somewhat unusual and rarely met object type, the multipoint, which combines what appear to be many separate points into a single multipoint object.