Inkscape/C3/Basics-of-Bezier-Tool/English

Title of script: Basics of Bezier curve

Author: Arthi. A

Keywords: Bezier curve, draw straight lines and closed paths, draw curved lines,

Visual cue	Narration
Opening Slide	Welcome to the Spoken Tutorial on “Basics of Bezier tool” using Inkscape.
Learning Objectives (Slide)	In this tutorial We will learn to Draw straight lines and closed shapes Draw curved lines Add, edit and delete nodes
System requirement (Slide)	To record this tutorial, I am using Ubuntu Linux 12.04 OS Inkscape version 0.48.4
	I will be recording this tutorial in maximum resolution mode. This is to accommodate all the tools that will be demonstrated.
Open Inkscape	Let us open Inkscape.
Click on Bezier tool	First let us draw a straight line using Bezier tool. The Bezier tool is right below the Pencil tool. Let's click on it.
Point to Tool controls bar	Observe the 4 options in the Tool controls bar at the top left. There are 4 modes of drawing bezier curve. By default, the Create regular bezier path option is enabled.
Click and drag >> Click once and right click	Click once on the canvas and move the cursor to the other end. Click once again. Notice that the line drawn is highlighted in green color. Now right-click to complete the line.
Point to end points	The two end points of the line are called nodes. We will learn more about them a little later. <<PAUSE>>
Draw a triangle	Next, let us draw a triangle. First draw a slanted line. Click once and draw another line at an angle.
Draw a triangle	Now click once more to draw a third line and join it with the starting node to complete the triangle.
	Next, we will draw a curved line using bezier tool.
Draw straight line >> Click and drag	Click on the canvas to draw a straight line. Click again, hold and drag to form a curve.
Click once and right click	Right-click to complete the curve.
Draw some sample curves	In a similar way, draw some more curve shapes on the canvas. Remember these steps- Click and draw a straight line. Click again, hold and drag to form a curve. Then right-click to complete the curve.
Delete all the shapes	Press Ctrl + A and clear the canvas before proceeding further.
	Next let us learn how to draw a closed curved path.
Draw a curved line >> Release the mouse and notice curved path	First draw a curved line on the canvas. Then we release the mouse and move the cursor away from the end node of the curved line. We see a curved path in red color.
Click once >> Straight path >> click and drag	If you click once and move the cursor, we see a straight path in red color. To make it as curve click and drag.
Release the mouse and notice curved path >> click and drag	Again at the end node the line curves as we move.
Click once >> Straight path >> click and drag	Again click once we see a straight path in red color. To make the straight line curve, click and drag
Click once >> move to the starting node and close the path	Again at the end node the line curves as we move. Move the cursor and go back to the starting node and close the path.
Tool controls bar >> Click on second icon	Go to Tool controls bar. Click on the second icon of the mode. This helps to create spiral paths and irregular shapes.
Draw some irregular curves	Draw some irregular curves and close the path. Observe that it transforms into the closest spiral shape. Let me clear the canvas now. <<PAUSE>>
Tool controls bar >> Click on third icon	The third icon creates only straight lines. Click on it and draw lines on the canvas.
Draw straight lines	Note we cannot draw curved lines in this mode. We can draw triangles or polygons which have straight sides.
Tool controls bar >> Click on fourth icon	Click on the last icon and draw on the canvas.
Draw a rectangle with 3 clicks.	In this mode, we can draw only parallel and perpendicular lines i.e. either vertical or horizontal lines. So, we can draw squares and rectangles in this mode. <<PAUSE>>
Delete the shapes >> Click on bezier tool	Let me delete all the shapes drawn.
Point to Shape option >> Click on drop down list	Shape option helps to draw lines or curves in a particular shape. Click on the drop down button.
Point to the 5 options	There are 5 options here- None, Triangle in, Triangle out, Ellipse, From clipboard.
Point to None	The first option that is None does not give any effect. So we will move on to Triangle in.
Click on Triangle in >> Draw a line	Click on it and draw a line on the canvas. The line is transformed to a triangle shape inwards.
Click on Triangle out >> Draw a line	Next click on Triangle out and draw a line on the canvas. Now a triangle shape is formed outwards.
Click on Ellipse >> Draw a line	Click on the Ellipse and draw a line. Observe that the line is in ellipse shape.
Point to From clipboard	We will learn about the last option that is From clipboard in later tutorial. <<PAUSE>>
Point to the Node tool	Now, let us learn to add, edit and delete nodes. This can be done using the Node tool.
Delete the lines	Delete the lines on the canvas.
Mode to regular path >> Shape to None	Go to Tool controls bar. Change the Mode to regular path and Shape to None.
Draw a human palm	Come back to the canvas and draw a rough human palm.
Click on the Node tool	Now click on the Node tool.
	Notice all the nodes in this figure are visible.
	Turn your attention to the Tools Controls bar.
Point to Tool controls bar	The first 6 icons here, helps to add and delete nodes and paths. Refer to the tool tip to understand better.
Click on a segment >> Point to nodes Click on Add node >> Point to the newly added node	Click on any segment. Notice both the nodes turn blue. Then click on the Add node option. Observe that a new node has been added exactly in-between the nodes of the selected segment.
Repeat the above steps for a smaller segment	Now select a smaller segment and repeat the above steps.
Point to the newly added node	You will see that a new node is added at the mid-point of the smaller segment.
Select the node	Now, select the newly added node.
Click on Delete node	Click on Delete node option. The node is now deleted.
Click on bezier handle icon	Click on any one of the nodes on the palm. To make the bezier handle visible click on the last but one icon on the Tool controls bar.
Point to bezier handle	Now the bezier handles for the selected segment is visible.
Click on any segment and move	If not, then just click on the segment and without releasing the mouse, move it a little. The segment will curve and the bezier handles will be visible now.
Click on end points >> rotate and resize	Click on the handles to resize and rotate the selected node.
Click on end points >> rotate and resize	In a similar way, modify the other nodes too.
Point to join node icon	The next icon helps to join nodes.
Point to extra node on small finger >> select it >> click on join node icon	Observe there is an extra node on the index finger. Select the extra middle node and the top node by using the Shift key. Now click on join node icon. Observe that the nodes are now joined together.
Point to break path icon	The next icon helps to break path at selected nodes. Let now break the connection between the thumb and the index finger.
Select node in between thumb and index finger >> click on break path icon	So select the joining node in between and click on break path icon.
Unselect the node >> select it again.	Unselect the node. Then select it again and move it a little. You will notice that the path is broken and the nodes are separated into 2 distinct nodes.
Select same 2 nodes >> click on next icon	To join them, select the same 2 nodes and click on the join selected end-nodes icon on the Tool controls bar. Notice, a new path is created between these 2 nodes.
Click on next icon >> Press Ctrl + Z	Click on the next icon i.e. Delete segment icon to remove the path or segment. Now the path is removed. Press Ctrl + Z to undo this action
Move hand aside. Click on the Bezier tool.	Let me keep this hand aside. Click on the Node tool once again. <<PAUSE>>
Point to the next 4 icons	Let us learn how to use next 4 icons on the Tool controls bar. These icons helps to edit the selected nodes.
Draw an inverted U shape >> Click on Node tool	Using the Bezier tool draw an inverted U shape. Click on the Node tool. Observe there are 3 nodes.
Select top node >> Click on Make selected nodes corner icon	Select the top node and click on Make selected nodes corner icon on the Tool controls bar.
Move the end points of the bezier handle	This makes it as the corner node. Click on the bezier handles and move them up and down to see the change.
Click on the node smooth icon	Click on the next icon to make the node smooth. Observe the change in the shape.
Click on the node symmetric icon	Click on the next icon which makes the node symmetric.
Click on the node auto smooth icon	Click on the next icon which makes the node auto smooth. <<PAUSE>>
Select the left segment >> click on first icon	The next 2 icons works only on segments. So, select the left segment of the U shape and click on the first icon.
Click on next icon	As the tool tip says, the segment is now made into a straight line. Click on the bezier handle and try to move. You will see that we cannot make it curved.
Click on next icon	Click on the next icon to make it a curved line again. Now move the bezier handles and observe now we can make it into a curve shape. <<PAUSE>>
Click on next icon	Click on the next icon to convert selected object to path.
Click on next icon	Click on the next icon to convert the stroke to path. Click and drag the nodes to make the strokes visible. <<PAUSE>>
Point to next X and Y co ordinates	The next 2 icons helps to move the selected nodes in X and Y directions respectively.
Click on up and down arrows of X and Y	Click on the up and down arrows and observe the change.
Point to next 2 icons	The next 2 icons works only if the path has clipping and masking effects. You can explore these options on your own. <<PAUSE>>
Summary (Slide)	Let us summarize. In this tutorial we learnt to Draw straight lines and closed shapes Draw curved lines Add, edit and delete nodes
Completed assignment	Here is an assignment for you Draw a flower with 5 petals, 1 stem and 2 leaves using bezier tool. Color the petals with pink color. Color the stem and leaves with green color.
Completed assignment	Your completed assignment should look like this.
About Slide	The video available at the following link summarizes the Spoken Tutorial project. Pls watch it.
About Slide	The Spoken Tutorial Project Team conducts workshops and gives certificates for those who pass an online test. For more details, please write to us.
About Slide	Spoken Tutorial Project is supported by NMEICT, MHRD, Government of India. More information on this Mission is available at this link.
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