Vector Feature Drawing

iXGIS provides comprehensive drawing tools for point, line, and polygon features. This guide explains the available feature drawing methods.

Snapping Options

Before drawing features, decide whether to enable Snapping.

Snapping helps connect or align features accurately to specific positions such as endpoints, vertices, and edges. It improves editing accuracy and efficiency, creates seamless connections between features, and helps avoid topology errors such as dangling points and gaps.

• Enable Snapping

  Step 1: Click the Snapping drop-down button.

  Step 2: Enable Snapping.

  Step 3: Select snapping types. Endpoints and edges are supported.

  Step 4: Configure other snapping options, such as XY tolerance and snapping tips.

• How Snapping Works

  Snapping is usually enabled while drawing features. For example, if you have already created one feature and want to create another feature whose boundary must touch it, Snapping helps place the new boundary exactly on the existing edge or endpoint. Without Snapping, hovering over the boundary does not constrain the pointer. With Snapping enabled, the pointer snaps to the feature edge or endpoint and displays the current layer name when it reaches a valid snapping target.

Feature Drawing Workflow

Feature drawing is used to interactively create basic vector features such as points, lines, and polygons, from simple point markers to complex polygon outlines. In typical workflows, enable Topological editing and Snapping before drawing.

Select a Layer

Select the layer where the new feature will be saved.

Choose the layer to edit based on the required geometry type: point, line, or polygon. Only visible layers are listed.

Start Drawing

After you select a data layer, iXGIS displays the feature forms supported by the current layer type:

• Point layer
• Multipoint layer
• Line layer
• Polygon layer

Draw Features

Use the drawing tools to create point, line, and polygon features.

Draw Point Features

You can create points directly or create a point at the end of a temporary line.

Create Points Directly

Click a location on the map with the left mouse button to add a point feature.

You can also right-click to open the drawing options and enter Absolute XYZ coordinates to create a point feature.

Line Endpoint Point

Line endpoint point creates a point feature at the endpoint of a temporary line. You first define direction and length using line construction methods. After you click Finish, the system deletes the temporary line and creates a point feature at its endpoint.

This method is useful when you need to locate a point accurately with direction and distance constraints, such as creating a second point from a known point by azimuth and distance.

Example: create a second point from the first point with an azimuth of 90 degrees and a distance of 300 m.

Step 1: Select a point layer and enable Snapping options as needed. In the point construction methods, select Line endpoint point, then click the map to set the start point. You can snap to an existing point or endpoint.

Step 2: Use Fixed direction to set the direction to 90 degrees, then use Fixed length to set the length to 300 m. Click the map to set the endpoint of the temporary line.

Step 3: Right-click to open the drawing options and click Finish. The system deletes the temporary line and creates a point feature at its endpoint.

Draw Multipoint Features

A multipoint feature is a geometry type where one feature contains multiple points. It is different from multiple point features:

• Multiple point features: each point is one record and can have its own attributes.
• Multipoint feature: multiple points share one record and the same attributes.

Example use case: one object is represented by multiple point locations, such as several entrances to one facility that need to be managed as one object.

Steps:

1. Select the target multipoint layer.
2. Select Multipoint in the drawing tools.
3. Click the map to add point locations one by one.
4. Finish drawing by double-clicking the left mouse button, or right-clicking to open the menu and clicking Finish.

astuce

For accurate positioning during drawing, right-click to open the drawing menu and use Absolute XYZ or other constraint methods, depending on the available options in the interface. You can also switch point construction methods to use different point drawing forms.

Draw Line Features

A line feature consists of an ordered sequence of connected vertices. The general operation is:

• Click to add a vertex.
• Move the pointer and click again to add the next vertex.
• Finish by double-clicking the left mouse button, or right-clicking and clicking Finish.

Enable Snapping, such as endpoint or edge snapping, to connect lines accurately to existing features.

Polyline

Add vertices one by one using the general line drawing operation. To control direction, length, or coordinates accurately, right-click during drawing and use options such as Absolute XYZ, Relative XYZ, Direction and distance, Fixed direction, and Fixed length.

Right-Angle Line

Creates orthogonal line segments.

This method constrains adjacent line segments to maintain right angles as much as possible. It is useful for drawing building outlines, road edges, and other regular geometries. Other operations are the same as polyline drawing: click to add vertices and double-click or click Finish to end drawing.

Radial Line

Creates multiple line segments radiating outward from a center point.

First set the center point, then set the endpoint of each radial line. This method is useful for drawing radial lines such as sight lines, radial roads, or sector boundaries. Finish the drawing the same way as a polyline.

Freehand Line

Creates a line that follows the pointer movement.

Press and hold the left mouse button in the layer and drag to draw. Release the left mouse button to finish.

astuce

Freehand lines usually contain many vertices. If you need a more regular line shape later, use tools such as Simplify or Smooth as appropriate for your data processing workflow.

Curve

Creates a smooth, nonlinear line feature.

Add control points as prompted to define the curve shape, then double-click or click Finish to end drawing. Curves are suitable for smooth boundaries such as bends and rivers.

Polygon Features

A polygon feature consists of a closed boundary, or outer ring, and may include inner rings. The general operation is:

• Click to add at least three vertices.
• Finish by double-clicking the left mouse button, or right-clicking and clicking Finish. The system closes the boundary automatically.

Enable Snapping to make new boundaries meet existing boundaries exactly.

Polygon

Draws a polygon freely. This is the default method.

Add vertices one by one using the general polygon drawing operation. To control direction, length, or coordinates accurately, use the corresponding constraints from the right-click drawing menu.

Rectangle

Creates a rectangle.

Usually, click twice to define the rectangle extent, such as by diagonal corners or width and height, depending on the interface interaction. You can also enter exact parameters from the right-click menu during drawing.

Square

Creates a square.

Click to set the center point, move the pointer to set the side length and adjust the rotation angle, then click again to finish. You can also enter parameters such as side length and direction from the right-click menu.

Circle

Creates a circle.

Usually, set the center point first, then set the radius to finish drawing. You can also enter parameters such as radius from the right-click menu, depending on the interface.

Ellipse

Creates an ellipse.

Usually, several steps are required to define the ellipse direction and major and minor axes, such as setting the center, the major-axis direction and length, and then the minor-axis length.

Right-Angle Polygon

Creates a polygon whose adjacent edges are perpendicular to each other.

This method constrains adjacent edges to maintain right angles as much as possible. It is useful for drawing building outlines, regular parcels, and similar geometries. Other operations are the same as polygon drawing.

Freehand Polygon

Creates a polygon that follows the pointer movement.

Press and hold the left mouse button in the layer and drag to draw. Release the left mouse button to finish.

Right-Click Drawing

Advanced drawing options provide precise input and constraints for the next point or vertex during drawing, including coordinates, direction, distance, and angle relationships. When drawing point, line, or polygon features, you can right-click at any time to open the drawing menu and select the required option.

General steps:

1. Start drawing a point, line, or polygon.
2. Right-click where you need an accurate point placement to open the drawing menu.
3. Select an advanced drawing method and enter values or select reference objects as prompted.
4. Click to confirm the point placement. Repeat as needed, then double-click or click Finish to end drawing.

Absolute XYZ

Absolute XYZ places the next point or vertex directly at a specified coordinate. It is suitable for coordinate staking, placing points by control points, and digitizing quickly from table coordinates.

Steps:

1. Right-click during drawing to open the drawing menu.
2. Select Absolute XYZ, enter coordinate values, and confirm.
3. The system creates the point or vertex at that coordinate.

astuce

If the map uses a geographic coordinate system, XYZ values usually correspond to longitude, latitude, and elevation, and XY units are degrees. If the map uses a projected coordinate system, XY values are usually projected coordinates and the units are typically meters.

Relative XYZ

Relative XYZ creates the next point or vertex by entering offsets, such as dX, dY, and dZ, from the current point. It is suitable for regular boundaries, array-style point placement, and constructing adjacent boundaries by offsetting a fixed distance.

Steps:

1. Set the start point, or current point, on the map.
2. Right-click to open the drawing menu, select Relative XYZ, enter offsets, and confirm.
3. The system creates the next point or vertex by the specified offsets.

astuce

If the map uses a geographic coordinate system, XYZ values usually correspond to longitude, latitude, and elevation, and XY units are degrees. If the map uses a projected coordinate system, XY values are usually projected coordinates and the units are typically meters.

Direction and Distance

Direction and distance determines the next point or vertex from the current point by azimuth and distance. It is suitable for staking by azimuth and drawing segments along a road direction.

Steps:

1. Set the current point.
2. Right-click to open the drawing menu, select Direction and distance, enter the direction and distance, and confirm.
3. The system creates the next point or vertex.

Fixed Direction

Fixed direction locks the azimuth of the current segment. You only need to determine the length, either by moving the pointer or by using Fixed length. It is suitable when multiple segments need the same direction.

Steps:

1. Set the current point.
2. Right-click to open the drawing menu, select Fixed direction, and enter a direction value.
3. Move the pointer to set the length and click to place the point, or use Fixed length to enter the length.

remarque

Azimuth uses north as 0 degrees and increases clockwise: north 0 degrees, east 90 degrees, south 180 degrees, and west 270 degrees.

Fixed Length

Fixed length locks the length of the current segment. You only need to determine the direction. It is suitable for drawing equal-length edges or adding vertices at a fixed step distance.

Steps:

1. Set the current point.
2. Right-click to open the drawing menu, select Fixed length, and enter a length value.
3. Move the pointer to choose the direction and click to place the point.

remarque

In a geographic coordinate system, length calculation uses geodesic distance. In a projected coordinate system, length calculation uses planar distance in the current projected coordinate system.

Deflection

Deflection uses the previous segment as a reference and creates the next segment direction by an entered deflection angle. It is commonly used to draw polylines by turning angles.

Steps:

1. Enable Snapping.
2. Draw the previous segment so the current point becomes a vertex.
3. Right-click to open the drawing menu, select Deflection, and enter the deflection angle.
4. Move the pointer to set the length and place the point, or use Fixed length to enter the length.

The deflection angle is measured as an azimuth-based turn from the previous segment. A value such as 90 degrees creates a right-angle turn according to the current calculation rules.

important

Deflection uses azimuth for angle calculation. In a projected coordinate system, the deflection angle is consistent with the angle calculated from projected coordinate values. In a geographic coordinate system, the deflection angle is not the same as an angle calculated only from longitude and latitude values.

Segment Deflection

Segment deflection first selects a reference segment and then creates a new segment direction by a deflection angle. It is suitable for constructing offsets or turns based on the direction of an existing line feature.

The segment deflection angle uses the reference segment as the baseline and is calculated by the azimuth method used in the geographic coordinate system.

Steps:

1. Enable Snapping.
2. Select or snap to a reference segment.
3. Right-click and select Segment deflection, then enter the deflection angle.
4. Set the length and place the point.

A deflection such as 270 degrees creates a new direction based on the selected reference segment and the current azimuth calculation rules.

Perpendicular

Perpendicular draws a new segment perpendicular to a reference segment. It is suitable for orthogonal structures, building boundaries, and perpendicular construction lines.

Steps:

1. Enable Snapping.
2. Snap to or select the reference segment.
3. Right-click and select Perpendicular, then move the pointer to set the length and place the point.

Parallel

Parallel draws a new segment parallel to a reference segment. It is suitable for road edges, parallel utility lines, and regular boundaries.

Steps:

1. Enable Snapping.
2. Snap to or select the reference segment.
3. Right-click and select Parallel, then move the pointer to set the length and place the point.

Finish Part

Finish part creates multipart features in one drawing operation. After completing the first part, click Finish part to start drawing the next part. All parts are saved as one feature.

Common scenarios:

• One feature consists of multiple separated polygons, such as one management unit containing several disconnected parcels.
• One feature consists of multiple disconnected line segments.

attention

Use Finish part only when the geometry type of the target layer supports multipart features.

Summary

Method	Purpose	Common uses	Notes
Absolute XYZ	Creates a point or vertex from explicit coordinates.	Coordinate staking and placement by known control points.	Coordinate units and meanings depend on the current map coordinate system, such as projected coordinates or longitude and latitude. Follow the interface prompts.
Relative XYZ	Creates a point or vertex by offsets from the current point.	Create adjacent points by shifting a fixed distance; auxiliary drawing for regular arrays.	Offset direction and units follow the interface prompts. Best suited to projected coordinate systems.
Direction and distance	Creates a point or vertex from the current point by direction and distance.	Locate a point from a known point by azimuth and distance; draw segments along a heading or road direction.	Direction origin rules and distance units follow the interface prompts.
Fixed direction	Locks the segment direction and lets you adjust only the length.	Draw multiple segments in parallel directions; maintain a consistent trend.	Often used with Fixed length for fixed-direction and fixed-length drawing.
Fixed length	Locks the segment length and lets you adjust only the direction.	Draw equal-length edges; advance vertices by a fixed distance.	Often used with Fixed direction.
Deflection	Uses the current segment as a reference and creates the next segment by a deflection angle.	Draw road polylines or regular polylines by turn angles.	The deflection angle is calculated according to interface rules. Whether negative angles are supported depends on the interface.
Segment deflection	Uses a reference segment as the baseline for deflection and draws a new segment.	Draw by deflection from an existing line feature.	Usually requires Snapping and a selected reference segment.
Perpendicular	Draws a perpendicular segment from a reference segment.	Draw perpendicular lines, building right-angle edges, and orthogonal structures.	Usually requires Snapping and a selected reference segment.
Parallel	Draws a parallel segment from a reference segment.	Draw parallel edges, road edges, and utility lines.	Usually requires Snapping and a selected reference segment.
Finish part	Creates a multipart feature in one drawing operation.	Create multiple line or polygon parts as one feature.	Use only when the target layer geometry type supports multipart features.

Point Construction Methods

Point construction methods are geometry construction tools used to determine point locations accurately when drawing point features or line and polygon vertices.

Scope: when drawing Point, Multipoint, Polyline, Polygon, and similar features, you can switch point construction methods as needed.

astuce

Point construction methods answer how a point is constructed. Advanced drawing options answer where the point is placed, such as by coordinate, direction, or distance. The two can be used together.

Direct Point

The default method. Click the map to place the point. For exact coordinates, right-click and use Absolute XYZ.

Intersection

Creates a point at the intersection of two lines or boundary segments. It is usually used when the point must be placed exactly at the intersection of two extended edge directions.

Steps:

1. Select the first edge or segment as the reference direction line as prompted.
2. Select the second edge or segment.
3. If the two reference lines intersect, the system creates a point at the intersection. If multiple candidate points exist, select one as prompted by the interface.

Direction-Direction

Determines a point location by the intersection of two direction lines. It is suitable for determining a point from two different positions by intersecting directions.

Steps:

1. Draw or specify the first direction line: set the start point and define its direction by rotating or entering a direction.
2. Draw or specify the second direction line.
3. The system creates a point feature or vertex at the intersection of the two direction lines.

Direction-Distance

Determines a point location by the intersection of one direction line and one circle, or distance constraint. A common use is to define a ray from point A by direction while requiring the point to be a specified distance from point B.

Steps:

1. Draw or specify a direction line.
2. Draw or specify a circle by setting the center and entering or setting the radius.
3. The system creates a point at the intersection of the direction line and circle. If two intersections exist, select one as prompted by the interface.

Distance-Distance

Determines a point location by the intersection of two circles. It is commonly used when the distances from the point to points A and B are both known.

Steps:

1. Draw or specify the first circle by setting the center and entering or setting the radius.
2. Draw or specify the second circle.
3. The system creates a point at the intersection of the two circles. If two intersections exist, select one as prompted by the interface.

Line Midpoint

Creates a point at the midpoint of a line segment. It is suitable for quickly getting the midpoint between two points.

Steps:

1. Specify the start point and endpoint of a segment, or select an existing segment.
2. The system creates a point at the midpoint of the segment.