⛔️ This article is for a legacy version of Scan2CAD. See our updated tutorials. ⛔️

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Define a set of warp control points

 

A source point is a point to be moved during a warp. Each source point has a corresponding destination point, which is the point that Scan2CAD will try to move it to.

 

Warp control points are up to 20 source-destination point pairs that define how a raster image will be warped when you use Raster Effects Menu > Warp.

There are two types of control point: lock control points and move control points.

Lock control points are points that you don’t want to move during the warp – the source point is the same as the destination point.
Move control points are points that you want to move during the warp – the source point and the destination point are different.

 

Add a lock control point by mouse

Add a move control point by mouse

Add a control point by typing coordinates

Automatically add control points around the raster image edges

Delete one control point

Delete all control points

Omit a control point from a warp run

Save a set of control points

Load a set of control points

View control points on the screen

 

Control point display is not persistent, meaning that control points will no longer be displayed on the screen if you redraw, zoom, pan etc. To display them, press Shift+C. If you change the control points the display will not be updated until you use Shift+C again.

 

Add a lock control point by mouse

1. Start adding the control point in any of the following ways:
Press Shift+A.
Select Raster Effects Menu > Warp > Add (Mouse) Control Point.
Press Shift+D or select Raster Effects Menu > Warp > View/Edit Control Points and then click on the Add (Mouse) button.
2. Position the cursor at the lock control point position.

You can either position the cursor visually or position it at an exact coordinate location.

As you move the cursor over the image, the prompt at the bottom of the screen displays the cursor’s coordinate position.

Normally the source and destination coordinates that are displayed are the coordinates of the raster image with 0,0 at the top left of the image. However if the image has been scaled using the Geo option in the Vector Scale Settings dialog, the source coordinates that are displayed are the coordinates of the raster image with 0,0 at the top left of the image. The destination coordinates are preceded by the word *Geo and are the real world coordinates with their origin at the bottom left of the image.

If you zoom into the image you will be able to locate exact coordinate positions easily because the cursor will have a box around its tip that is the size of one pixel. If you move the cursor slowly, the box will “jump” from pixel to pixel.

3. Click.

The lock control point is marked by a red numbered circle.

 

You may find it helpful to display a grid when adding lock control points.

 

Add a move control point by mouse

1. Start adding the control point in any of the following ways:
Press Shift+A.
Select Raster Effects Menu > Warp > Add (Mouse) Control Point.
Press Shift+D or select Raster Effects Menu > Warp > View/Edit Control Points and then click on the Add (Mouse) button.
2. Position the cursor at the source point.

You can either position the cursor visually or position it at an exact coordinate location.

As you move the cursor over the image, the prompt at the bottom of the screen displays the cursor’s coordinate position.

Normally the source and destination coordinates that are displayed are the coordinates of the raster image with 0,0 at the top left of the image. However if the image has been scaled using the Geo option in the Vector Scale Settings dialog, the source coordinates that are displayed are the coordinates of the raster image with 0,0 at the top left of the image. The destination coordinates are preceded by the word *Geo and are the real world coordinates with their origin at the bottom left of the image.

If you zoom into the image you will be able to locate exact coordinate positions easily because the cursor will have a box around its tip that is the size of one pixel. If you move the cursor slowly, the box will “jump” from pixel to pixel.

3. Press down your left mouse button. Holding down your left mouse button, move your mouse to the destination point.

You can either do this visually or using the coordinates displayed in the prompt at the bottom of the screen. If the image has been scaled using the Geo option in the Vector Scale Settings dialog the displayed real world coordinates allow you to position the destination point at an exact real world coordinate location which is useful for georeferencing.

As you move your mouse a line is drawn from the source point to the destination point.

4. Raise your left mouse button.

The source point is marked by a green circle and the destination point is marked by a red numbered circle. The two circles are joined by a dashed line.

 

You may find it helpful to display a grid when adding move control points.

 

Add a control point by typing coordinates

1. Press Shift+D or select Raster Effects Menu > Warp > View/Edit Control Points.

The Edit Warp Control Points dialog appears.

2. Click on the Add (Keybd) button.

Scan2CAD adds a new line to the control points table in the dialog.

3. Type the coordinates of the source and destination points into the new line.

All coordinates are raster image coordinates with 0 0 at the top left of the image.

 

Automatically add control points around the raster image edges

1. Press Shift+D or select Raster Effects Menu > Warp > View/Edit Control Points.

The Edit Warp Control Points dialog appears.

2. Click on the Add Edges button.

Scan2CAD automatically adds eight lock control points around the edges of the raster image. These help to prevent the image picture from distorting away from the image edges when you warp it.

 

Delete one control point

1. Press Shift+D or select Raster Effects Menu > Warp > View/Edit Control Points.

The Edit Warp Control Points dialog appears.

2. Click on the Remove button.
3. Click in any white field belonging to the control point you want to remove.

 

Delete all control points

1. Press Shift+D or select Raster Effects Menu > Warp > View/Edit Control Points.

The Edit Warp Control Points dialog appears.

2. Click on the New button.

 

Omit a control point from a warp run

1. Press Shift+D or select Raster Effects Menu > Warp > View/Edit Control Points.

The Edit Warp Control Points dialog appears.

2. Uncheck the control point’s Use option.

 

Save a set of control points

1. Press Shift+D or select Raster Effects Menu > Warp > View/Edit Control Points.

The Edit Warp Control Points dialog appears.

2. Click on the Save button.
3. Type a name for the file into the File Name section of the Save As Control Points File dialog.

Control points are stored in files with .Con (control) extensions.

4. Click Save.

The control points displayed in the Edit Warp Control Points dialog are saved under the name you have specified.

 

Load a set of control points

1. Press Shift+D or select Raster Effects Menu > Warp > View/Edit Control Points.

The Edit Warp Control Points dialog appears.

2. Click on the Load button.
3. Select the control point file you want to load from the Load Control Points File dialog.
4. Click Open.

The control points in the file you have loaded appear in the Edit Warp Control Points dialog.

 

View control points on the screen

Press Shift+C or select Raster Effects Menu > Warp > View Control Points.

The control points are displayed on the screen.

Control points marked with a *  are currently omitted from the warp run.

 

 

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