Inkscape/C2/Layers-and-Boolean-operations/English

Title of script: Layers and Boolean operations

Author: Arthi. A

Keywords: Add a new layer, Rename and position it, Add various filters, Create boolean operations

Visual cue	Narration
Opening Slide	Welcome to the Spoken Tutorial on “Layers and boolean operations” using Inkscape.
Learning Objectives (Slide)	In this tutorial We will learn about Layers Filters Boolean operations
System requirements (Slide)	To record this tutorial, I am using Ubuntu Linux 12.04 OS Inkscape version 0.48.4
Go to Dash home and type “Inkscape”.	Let us open Inkscape. Go to Dash home and type Inkscape.
Click on Inkscape logo	Click on the Inkscape logo.
Open the Assignment_2.svg	Let's open the Assignment_2.svg file that we created earlier. I had saved it in documents folder.
	First, we will learn about Layers in Inkscape.
Go to Layers >> Click on Layers	Go to Layer menu and click on Layers option. Now the Layer palette is opened on the right side of the interface.
Point to the default layer	By default a layer is there. You can see, that is named as Layer 1.
Click on plus icon	To add or create a new layer, click on the plus icon on the Layer palette.
	A dialog box named Add layer opens up.
Point to the Layer name	In the Layer name text box, we can assign a name to the layer. I will name this layer as eye.
Click on the drop down list	Now, we can decide the position of the layer by clicking on the Position drop down list.
Point to the 3 options in the drop down list	There are 3 options here. Above current will keep this layer on top of the current layer. Below current will place this layer below the current layer. As sublayer of current indicates that it will be a part of the current layer.
Click on Above current	I will position it as Above current and click on the Add button.
Point to the eye layer	Notice a new layer named eye is now visible in the Layer palette.
Add another layer >> Name it bow	In a similar way, create another layer named bow.
Point to the 3 layers	Now we have 3 layers in the Layer palette.
Click on Layer 1 >> Rename it as circle	Next let us learn to rename a layer. First double click on Layer 1. And then rename it as circle and press Enter.
Point to the shapes on the canvas	Coming back to our canvas. There are 2 eyes and a bow. Let us move these shapes to the 2 different layers that we created.
Select the eyes >> Paste on the eyes layer	Select both the eyes by dragging the mouse. Now press Ctrl + X on your keyboard. The eyes have now disappeared.
Click on the eye layer	Now click on the eye layer in the Layer Palette.
On the canvas, press Ctrl + Alt + V	Come back to the canvas and press Ctrl + Alt + V.
Copy the bow >> Paste on the bow layer	Repeat the same action for the bow shape.
Click on any empty space on the canvas	Click on any empty space on the canvas to deselect all the objects. <<PAUSE>>
Slide	Eye and Lock icons The eye and lock icons help to hide and lock layers. When you hide a layer, you are able to see the objects on the subsequent lower layers clearly. When you lock a layer, you are able to prevent accidental edits to that particular layer. These are particularly useful when we have to work on large and complex graphic assignments.
Point to eye and lock	Notice 2 icons namely, an eye and a lock, on the left of each layer. We will now learn how to use these.
Lock bow layer	To lock or unlock layers, click on the lock icon. I have now locked the bow layer.
Unlock them	Note that if a layer is locked, we cannot make any changes to that layer.
Drag to select the bow	Let's try to select the bow on the canvas. You will notice that it is not possible to do so.
Unlock bow layer	Now, I will unlock the bow layer.
Drag to select the bow >> change the colour to blue and then back to red	Now, I am able to select the bow object and change its properties, as well. <<PAUSE>>
Point to the eye icon	To make a layer visible or invisible on the canvas, click on the eye icon to the left of the layer.
Click on the eye icon repeatedly	I am clicking on the eye icon for the bow layer. Observe what happens on the canvas. <<PAUSE>>
Click on bow layer.	Now, let me duplicate the bow layer.
Go to Layers >> Click on Duplicate Current Layer.	Now, go to Layer menu and click on Duplicate Current Layer option.
Point to bow copy layer	Notice a new layer named bow copy is created in the Layer Palette window.
Point to the canvas	But we cannot see the new bow on the canvas. That is because the bow object is overlapped on the previous layer.
Select the bow and move it.	Select the bow on the top layer and move it to one side to see both the bows. <<PAUSE>>
Click on circle layer	Select the circle layer.
Draw an ellipse	Draw an ellipse on the canvas encircling the eyes and the bows. Color it orange. The ellipse is seen in the background with the other objects visible above it.
Point to the 4 layer positioning icons	The four icons next to the plus icon in the Layers Palette, helps to position the selected layer.
Point to the first icon and click on it	The first icon raises the selected layer to be the topmost layer. The circle layer is currently selected. Observe that on clicking, the circle layer now becomes the topmost layer.
Point to the fourth icon >> Select the circle layer and click on the icon.	The last icon lowers the selected layer to be the bottom-most layer. Click on this icon. Observe that the circle layer is now the bottom-most layer.
Click on the second icon	The second icon raises the selected layer, one layer above. Click on this icon. The circle layer has moved above the eye layer. So the eyes are not visible.
Click on the third icon	The third icon lowers the selected layer, one layer below. Click on this icon. Now the circle layer has moved below the eye layer.
Point to the 4 icons	So, that is how these four icons can be used.
Point to the minus icon and then click on it	The minus icon at the end will delete the selected layer. Select the bow copy layer and click on it. Observe that the bow copy layer is no longer seen. <<PAUSE>>
Point to Blend mode	Blend mode is a shortcut to apply the Blend filter to an entire layer. This means that if objects overlap on the selected layers, Inkscape will do a pixel-by-pixel blend of the two objects.
Arrange circle layer to top	So, keep the circle layer on the top to make the filters visible.
Click on drop down list	Click on the drop down list of Blend mode. Notice there are 5 options.
Blend mode >> Click on Normal	The first option that is Normal, does not add any filter to the layer. Let me click on it. Observe no filter is added to the layer.
Click on Multiply >> Point to the canvas	Next click on Multiply. Notice that objects on the topmost layer, filters the light so that the objects on the bottom layers are visible. At the same time, it also blends or mixes the colors to form darker colors in the overlap regions.
Click on Screen >> Point to the canvas	Next option is Screen. Observe the top objects; they add lightness to the bottom objects. So, it blends or mixes the colours to form lighter colours in the overlap regions.
Click on Darken >> Point to the canvas	Select Darken. The objects on the top layer, darken the objects on the bottom layers.
Click on Lighten >> Point to the canvas	Now, let us select the last option that is Lighten. Here the top objects lighten the bottom objects.
Click on Normal >> Point to the canvas	If at any time you return the Blend mode back to Normal, the blend filters applied so far, disappears.
Click on Filters menu >> Click on ellipse >> Click on Filters menu >> Scroll down the various options DO NOT CLICK	We can see many more filters in the Filters menu. To apply any particular filter, first select the object first and then click on the desired filter.
Arrange circle layer to bottom	Move the circle layer to the bottom again.
Select eye >> Filters >> Blur >> Fancy blur	Let me select an eye. Go to Filters menu. Select Blur and Fancy blur. Observe the changes on the eye.
Select another eye >> Bevel >> Smart jelly	Let me select the other eye. Go to Filters menu. Select Bevel and Smart jelly. Once again observe the changes applied to the eye.
Select circle >> Filters >>Scatter >> Air spray	Now select the bow. Go to Filters menu. Select Scatter and Air spray The bow appears as if it has been air-sprayed.
	<<PAUSE>>
Point to Opacity	The Opacity option right below the Blend mode, helps to reduce the Opacity of the selected layer.
Reduce the Opacity level	Select the circle layer. Adjust the Opacity level and observe the change in the ellipse. <<PAUSE>>
	Next we will learn about boolean operations.
Go to Path menu >> Point to Boolean operations	Go to Path menu. These are the available boolean operations.
Draw a circle and square >> keep square above the circle	Keep the available shapes aside. Draw a square of green color and a circle of red color. Keep the circle above the square towards the side.
Select both >> Path menu >> Click on Union	=== Select both. Go to Path menu and click on Union. === Observe the 2 shapes are now joined together.
Press Ctrl + Z	Now press Ctrl + Z on your keyboard to undo this action.
Select both >> Path menu >> Click on Difference	Again select both. Go to Path menu. Click on Difference and observe what happens.
Press Ctrl + Z	Press Ctrl + Z again to undo this action.
Select both >> Path menu >> Click on Difference	Again select both the objects. Go to Path menu. Click on Intersection and observe the change in the shape.
Press Ctrl + Z	Press Ctrl + Z again to undo this action.
Select both >> Path menu >> Click on Exclusion	Again select both objects. Go to Path menu and click on Exclusion. Observe the change in the shape.
Press Ctrl + Z	Again press Ctrl + Z.
Select both >> Path menu >> Click on Division	Once again select both objects. Go to Path menu and click on Division. Click on the divided circle and move that part aside to see the result.
Press Ctrl + Z	Now press Ctrl + Z twice to undo these actions.
Select both >> Path menu >> Click on Cut path	Select both objects again. Go to Path menu and click on Cut path. Observe the change in the shape.
Move circle's stroke	Cut path option works only if the object has stroke. Unselect the shapes first. Now, select any one of the strokes and move it aside to make the cut path visible. <<PAUSE>>
Summary (Slide)	Let us summarize. In this tutorial, we learnt about Layers Filters Boolean operations
Assignment (Slide)	Here are 4 assignments for you Create a rectangle with pink color and a triangle with green color. Keep the triangle on the top of the rectangle. Select both. Use Union. It should look like a home icon. Name the layer as home. Draw a 2 circles. Keep one on top of the other. Select both and use Difference. It should look like a crescent.
Assignment (Slide)	* Draw an ellipse. Create a star with 10 corners. Keep it in the centre of the ellipse. Select both and apply Exclusion. Create 2 layers named crescent and star respectively. Cut the crescent shape and paste in crescent layer. In a similar way do for the star shape.
Completed assignment	Your completed assignment should look like this. <<PAUSE>>
About Slide	The video at the link shown, summarizes the Spoken Tutorial project. If you do not have good bandwidth, you can download and watch it.
About Slide	The Spoken Tutorial Project Team conducts workshops using spoken tutorials and gives certificates on passing online tests. For more details, please write to us.
About Slide	Spoken Tutorial Project is supported by the National Mission on Education through ICT, MHRD, Government of India. More information on this Mission is available at the link shown.
Acknowledgment	We have come to the end of this tutorial. This is Arthi and Saurabh from IIT Bombay, signing off. Thanks for joining.

Contributors and Content Editors

Arthi, Nancyvarkey