103-L-14 by mayank govil

LESSON 14 USING A DIGITIZER STRUCTURE 14.0

OBJECTIVES

14.1

INTRODUCTION

14.2

PEN-TABLET POWER PRESSURE

14.3

BRUSH STROKES

14.4

TYPES OF BRUSHES

14.5

FEATURES OF PEN-TABLETS 14.5.2 14.5.1

14.6

USING STROKES, DRAWING LINES AND SHAPES 14.6.1 14.6.2 14.6.3 14.6.4 14.6.5 14.6.6

14.7

PEN TILT AIRBRUSH

TO DRAW A PRESSURE-SENSITIVE LINE APPLYING BRUSH STROKES TO APPLY A PRESET BRUSH STROKE TO CREATE A CUSTOM BRUSH STROKE DRAWING LINES USING OTHER TOOLS IN COREL DRAW TO DRAW A STRAIGHT LINE

ASSIGNMENTS 14.7.1 14.7.2

CLASS ASSIGNMENT HOME ASSIGNMENT

14.8

SUMMING UP

14.9

POSSIBLE ANSWERS TO SELF-CHECK QUESTIONS

14.10

TERMINAL QUESTIONS

14.11

REFERENCES AND SUGGESTED FURTHER READING

14.12

GLOSSARY

14. USING A DIGITIZER In the previous lesson, we were introduced to the digitizer as a design tool. In this lesson we will learn more about some of the advanced functions that can be performed using a digitizer. You shall see that with the Corel draw software, digitizer serves the same purpose as that of a mouse. But the digitizer possesses one extraordinary feature namely the power of pressure sensitivity. In this lesson this aspect will be highlighted.

14.0 Objectives After going through this lesson, you will become: •

More comfortable with a digitizer.

•

Familiar with advanced features of the pen tablet power pressure options o Applying pressure o Tilt actions o Using the pen’s bearing o Air brush

•

Deft in using different types of brush strokes, drawing lines and shapes

14.1 Introduction All tablets are pressure sensitive. They literally feel the full range of pressure from the pen. The pressure sensitivity allows one to control drawing/painting software tools. By changing the pressure with which the pen is applied on the tablet, one can alter brush size, opacity of the image etc. For example, with a pressure-sensitive tool if you press hard you get an opaque image, a fatter paint brush and a darker stroke. Similarly, if you press lightly, you have a transparent clone, a thin brush and a gentle stroke of colour. A tablet can also sense the tilt of your pen in programs like Photoshop, and Painter, giving you the ability to tilt your brush for cool effects.

14.2 Pen-Tablet Power Pressure To demonstrate the pressure sensitive control, we will show some drawing /painting features using Corel. You will study more about Corel Draw features in the next lesson in Unit 5 of the Course No. CTD 104 and in course no. CTD 203. Some of the features that can be used with the help of Pen and Tablet include: 2

Artistic Media, Smart Drawing, Freehand, Polyline and Eraser. Pen tools, stylusenabled tools, like the Smudge Brush and Roughen Brush; they help you use a pen tablet to apply line effects. When Smudge Brush is selected in Corel Draw, you can use Property Bar options to activate the Pressure, Tilt, and Bearing settings on Pen/Stylus. Stylus options provide control over smudging operations in various ways. 14.2.1 Applying pressure When the Stylus Pressure option is selected, the Smudge Brush uses stylus pressure to apply varying degrees of Dryout to your strokes in Corel Draw. Dryout is a setting that enables diminishing or expanding nib width based on stylus pressure. With Stylus Pressure option selected, stylus pressure can be increased or decreased with the frequency of the applied spike effect. 14.2.2 Tilt action When you apply smudging, with the Stylus Tilt setting activated, the angle of your stylus relative to the tablet surface sets the elliptical shape of the Smudge Brush nib. With Stylus Tilt selected, the angle of your stylus controls the angle of the individual spikes. 14.2.3 Using bearing Using the Stylus Bearing option, you can control the angle of the elliptical nib shape by rotating the stylus in relation to the tablet surface. For example, the Smudge Brush can be used to apply distortions to an outline path to emulate the appearance of tall grass. Choosing Stylus Setting from the Spike Direction, drop-down list enables stylus movements to set the direction of the roughened spikes.

14.3 Brush Strokes When you apply smudging with the PEN Tilt setting activated, the angle of the Stylus relative to the tablet surface sets the elliptical shape of the Smudge Brush nib. Using the Stylus Bearing option (Fig. 14.1), you can control the angle of the elliptical nib shape by rotating the stylus in relation to the tablet surface.

Fig. 14.1

The Roughen Brush has similar options for controlling line roughening. This tool enables to create specialized line effects by applying jagged edges or spiked lines to the outline path of an object. Options on the Roughen Brush Property Bar in Corel Draw help to control the Frequency, Tilt, and Bearing of the roughening effects. Roughening applied to an outline path creates an alternate effect on tall grass illustration. Creative operations such as sketching, cartooning, airbrushing, painting, erasing, or even just applying interactive line effects are much more productive using Pen and Digitizer.

14.4 Types of Brushes There are more than 30 brushes designed in Corel Draw to produce textures resembling fabric and paper surfaces. The range in this collection focuses on rougher textiles, as these produce the most beautiful textures for backgrounds and surface details on 3D objects. Some of the brushes of Corel Draw are listed below: • Burlap Brushes

Based on both large textured nibs and small scattering nibs.

• Canvas Brushes

Similar to the burlap brushes but have finer textures; paper textures that are all rough, some resembling crumpled papers, others resembling hand-made papers with colour variations. Generic rough surfaces can be combined to produce some nice depth effects.

• Stitching Brushes

Designed to resemble stitches.

• Weave Brushes

They don't resemble any particular fabric.

• Wool Brushes

These produce a somewhat fuzzy, multi-hued surface.

14.5 Features of Pen-Tablets A large size tablet gives high degree of drawing precision and accuracy than smaller models. More the active tablet space available to sketch on, more details the pen strokes will produce. For hard-copy tracing operations, a large model that has a translucent tablet film is used to utilize the large hard-copy sizes. When using the tools in Corel PHOTO-PAINT to manipulate pixels, pen tablet is used with airbrush accessory or a pen model that includes a built-in pressure eraser for easy fixes. 14.5.1 Airbrush To control tool attributes, such as size, opacity, and exposure, Tablets provide the option of using a digital airbrush with adjustable finger wheel. 14.5.2 Pen tilt Tablets can sense the angle at which the pen is held (Fig. 14.2). Both, the amount and direction of tilt are measured and communicated to the software to allow tools to behave in the most natural way possible. Fig. 14.2

Self-check Questions 1.

What is the purpose of a Stylus Bearing options?

What types of operations are most productive with a digitizer?

State the various types of brushes on designed on Corel draw.

What do you mean by pressure sensitivity?

14.6 Using Strokes, Drawing Lines and Shapes 14.6.1 To draw a pressure-sensitive line i) Open the Curve flyout, and click the Artistic Media tool. ii) Click the Pressure button on the property bar. iii) This lets you draw curves with a pressure-sensitive pen controlling the width of the stroke. iv) If you want to make the edges of the line smooth, type a value in the freehand smoothing box on the property bar. v) Drag until the line is of the shape you want. vi) If you want to change the width of the line, type a value in the Artistic Media tool width box on the property bar. 14.6.2 Applying brush strokes Let us examine how to apply a variety of preset brush strokes, ranging from the strokes with arrowheads to ones that are filled with rainbow patterns. When you draw a preset (already defined) brush stroke, you can specify some of its attributes. For example, you can change the width of a brush stroke and specify its smoothness. You can also create custom brush strokes using an object or a group of vector objects. When you create a custom brush stroke, you can save it as a preset. Vector object is a specific object within a drawing that is created as a collection of lines rather than as patterns of individual dots or pixels. Vector objects are generated from mathematical descriptions that determine the position, length, and direction in which lines are drawn. 14.6.3 To apply a preset brush stroke i)

Open the Curve flyout, and click the Artistic media tool.

ii)

Click the Brush button on the property bar.

iii) Choose a brush stroke from the Brush stroke list box. If you want to smooth the edges of the brush stroke, type a value in the Freehand smoothing box on the property bar. iv) Drag until the stroke is of the shape you want. If you want to set the width of the stroke, type a value in the Artistic media tool width box on the property bar. If you have access to a brush stroke that is not listed in the Brush stroke list box, you can apply it by clicking the Browse button on the property bar, and locating the brush stroke file. 6

14.6.4 To create a custom brush stroke •

Select an object or a set of grouped objects.

•

Open the Curve flyout, and click the Artistic media tool.

•

Click the Brush button on the property bar.

•

Click the object or grouped objects.

•

Click the Save artistic media stroke button on the property bar.

•

Type a file name for the brush stroke.

•

Click to Save.

You can create custom brush strokes by clicking Effects Artistic Media, and specifying the settings you want on the Artistic Media Docker window/palette. 14.6.5 Drawing lines using other tools in Corel Draw Corel Draw is the most commonly used designing software as far as textile designing is concerned. Using this you can draw all kinds of different lines, from curved or straight lines to calligraphic lines can be drawn. Segments that are straight and curved in the same line can be created. You can draw straight or curved segments and then add one node at a time. You can also draw a curve by specifying width and height. Some lines have nodes and control points that you can manipulate to shape lines as you draw. What we mean by control points is that, the points that extend from a node along a curve that is being edited with the Shape tool. You can simulate the effect of a calligraphic pen when you draw lines. Calligraphic lines vary in thickness according to the direction of the line and the angle of the pen nib. You can control the thickness of a calligraphic line by changing the angle of the line you draw in relation to the calligraphic angle you choose. While drawing lines/shapes you can create pressure-sensitive lines, which vary in thickness. You can create this effect using the mouse or a pressuresensitive pen and graphics tablet. Both methods result in lines with curved edges and varying widths along a path. Software provides preset lines that let you create thick strokes in a variety of shapes. After you draw a calligraphic or preset line, you can apply a fill for colouring to it. Fill in Corel Draw is a colour-filling tool with different types, as uniform, fountain, or pattern fill applied to an area of an image.

14.6.6 To draw a straight line i)

Draw a straight line using the Polyline tool. •

Open the Curve flyout and click the Polyline tool.

•

Click where you want to start the line segment, and click where you want to end the line segment.

•

Double-click to end the line.

ii)

Draw a straight line using the Bézier tool. •

Open the Curve flyout, and click the Bézier tool.

•

Click where you want to start the line.

•

Double-click where you want to end the line.

If you want to create a multi-segment line, click where you want to end each new line segment and double-click to finish the line. iii)

Draw a straight line using the Pen tool. •

Open the Curve flyout, and click the Pen tool.

•

Click where you want to start the line. Double-click where you want to end the line.

•

If you want to create a jagged line, click where you want each new line segment to end. Double-click to finish the line.

•

Add line segments to an existing line: Using the Freehand tool, click the end node of a selected line, and click where you want the new segment to end.

iv)

Create a closed shape from a multi-segment line. •

Using the Freehand tool, click the end node of a multi-segment line. Click the first node.

•

You can constrain a line created with the freehand tool to a straight vertical or horizontal line by holding down Ctrl Key while you drag. You can change the angle of this line by clicking Tools Options, clicking Edit in the Workspace list of categories, and changing the value in the Constrain Angle box.

Draw a curved line using the Polyline tool. •

Open the Curve flyout, and click the Polyline tool.

•

Click where you want to start the curve, and drag across the drawing page. Double-click to finish the curve. 8

• vi)

This lets you draw lines and curves one segment at a time in preview mode. Draw a curved line using the Bézier tool.

•

Open the Curve flyout, and click the Bézier tool.

•

Click where you want to place the first node, and drag the control point in the direction you want the curve to bend.

•

Release the mouse button. Position the cursor where you want to place the next node, and drag the control point to create the curve you want.

•

Double-click to finish the curve.

This tool enables you to draw curves by placing nodes and shaping the segments between the nodes. vii)

Draw a curved line using the Pen tool. •

Open the Curve flyout and click the Pen tool.

•

Click where you want to place the first node, and drag the control point in the direction you want the curve to bend.

•

Release the mouse button. Position the cursor where you want to place the next node, and drag the control point to create the curve you want.

•

Double-click to finish the curve. This tool enables you draw curves one segment at a time.

You can erase a portion of a curved freehand line by holding down Shift and dragging backward over the line before releasing the mouse button. You can close an open curve object by selecting the curve object and clicking the Auto-close curve button on the property bar. Auto Close closes an open path. viii) Draw Curve using Curve Flyout Button.

ix)

•

To draw a curve by specifying width and height, open the Curve flyout, and click the 3 point curve tool.

•

This tool enables you to draw curves by specifying height and width

•

Click where you want to start the curve, and drag to where you want the curve to end.

•

Release the mouse button, and click where you want the center of the curve to be. To draw a calligraphic line. 9

•

Open the Curve flyout, and click the Artistic media tool.

•

Click the Calligraphic button on the property bar.

•

Type a value in the Calligraphic angle box on the property bar.

•

Drag until the line is of the shape you want.

If you want to make the edges of the line smooth, type a value in the Freehand smoothing box on the property bar. If you want to set the width of the line, type a value in the Artistic media tool width box on the property bar. The width you set is the maximum line width. The angle of the line you draw in relation to the calligraphic angle determines the line's actual width. You can also access calligraphic lines by clicking Effects Artistic media, and specifying the settings you want on the Artistic media>Docker window/palette tool of Corel Draw. x)

To draw a preset (pre-defined) line. •

Open the Curve flyout, and click the Artistic media tool.

•

Click the Preset button on the property bar.

•

Choose a preset line shape from the Preset stroke list box.

•

Drag until the line is of the shape you want.

If you want to the edges of the line smooth, type a value in the Freehand smoothing box on the property bar. If you want to set the width of the line, type a value in the Artistic media tool width box on the property bar.

14.7 Assignments 14.7.1 Class assignments i)

Draw a straight line using the Polyline tool.

ii)

Draw a straight line using the Pen tool.

iii) Draw a curved line using the Polyline tool. iv) Draw a curved line using the Bézier tool. v)

Draw a curved line using the Pen tool.

vi) Draw a Curve using Curve Flyout Button.

14.7.2 Home assignments i)

Make a drawing on a cartridge sheet in order to draw it on computer with the help of a digitizer, which can employ all the above tools that has been discussed in the present lesson.

14.8 Summing Up This Lesson describes: i)

The various features of Pen used with Digitizer.

ii)

Application of Pen-Digitizer in drawing and creation of different impressions of Strokes.

iii) The various tools of Corel Draw Software for helping you to create designs. After going through this lesson you should be able to create Documents, save them in your folder, and know the type of formats being used while saving your document.

14.9 Possible Answers to Self-check Questions 1.

Using the Stylus Bearing option, you can control the angle of the elliptical nib shape by rotating the stylus in relation to the tablet surface.

Creative operations such as sketching, cartooning, airbrushing, painting, erasing, or even just applying interactive line effects are much more productive using Pen and Digitizer.

Types of brushes: o Burlap Brushes Based on both large textured nibs and small scattering nibs. o Canvas Brushes Similar to the burlap brushes but have finer textures; paper textures that are all rough, some resembling crumpled papers, others resembling hand-made papers with colour variations. Generic rough surfaces can be combined to produce some nice depth effects. o Stitching Brushes

Designed to resemble stitches.

o Weave Brushes They don't resemble any particular fabric. o Wool Brushes 4.

These produce a somewhat fuzzy, multi-hued surface.

The pressure sensitivity allows one to control drawing/painting software tools. By changing the pressure with which the pen is applied on the tablet, one can alter brush size, opacity of the image etc. For example, with a pressure-sensitive tool if you press hard you get an opaque image, a fatter paint brush and a darker stroke. Similarly, if you press lightly, you have a transparent clone, a thin brush and a gentle stroke of colour. 11

14.10

Terminal Questions

Describe the various features of a Digitizer Pen.

What are Brush Strokes?

How is the Pressure Sensitivity of pen observed while drawing with Pen?

What are the various tools used for creating lines and shapes in Corel Draw?

14.11