Warm up
1 Look at the picture in this page: how is energy being produced? Is this energy renewable or non-renewable?
Renewable energy sources are not exhausted by their exploitation and theoretically can be used indefinitely. Examples include solar, wind, and water energy, and other resources that may be replenished such as timber or livestock.
Using sunlight to produce electricity through special devices such as solar collectors, photovoltaic plants and concave mirrors will not exhaust sunlight coming to Earth. The sun rises every day and its energy may be used – no matter how much of its energy is used one day, it will still be there the next one. Over time, and under the right conditions, forests grow again and timber can be sustainably harvested indefinitely.
Renewable sources and energy efficiency are no longer seen as niche sectors that are promoted only by governments and environmentalists.
renewable rinnovabili exhausted esaurite exploitation sfruttamento replenished rifornite devices dispositivi concave mirrors specchi concavi sustainably in maniera sostenibile concerns preoccupazioni peak oil picco di consumo
Increasing levels of investment suggest that sustainable energy has become mainstream and the future of energy production, as non-renewable sources decline.
This is reinforced by climate change concerns, nuclear dangers and accumulating radioactive waste, high oil prices, peak oil and increasing government support for renewable sources. These factors are commercialising renewable energy and enlarging the market; the demand for renewable energy is increasing, with the consequent adoption of new products to replace obsolete technology and the conversion of existing infrastructure to a higher standard. The use of renewable energy has grown continuously in the European Union: by 2020, it reached 22.1%, but the aim is to increase its energy efficiency by at least 32.5% by 2030. Most renewable energy sources are practically inexhaustible or renewable within a human lifetime, while fossil energy sources need over millions of years to replenish, and are the main source of man-made greenhouse gas emissions, thus contributing significantly to the climate crisis. In 2020, Sweden was the first of the EU countries in using renewables (60.1%) followed by Finland (43.8 %) and Latvia (42.1 %). These results were reached thanks to the use of hydropower and solid biofuels, more ecologically friendly than conventional energy sources; wind and solar energy have also increasingly contributed to the growth of renewable energy in final energy consumption in most EU countries.
More about
To date, there are two ways to exploit sunlight to obtain energy. They have similar names but work differently. Solar panels, also called solar thermal, convert sunlight to heat and then heat to electricity.
Photovoltaic cells, or solar cells, convert sunlight directly into electric current by way of carefully-engineered semiconductor materials. Though solar photovoltaics are more efficient converters of sunlight, they are also more expensive.
reading comprehension
2 Read the text and match the two parts of the sentences.
1 Renewable energy sources
2 Solar collectors use
3 Sunlight is a source of energy
4 Sustainable energy has become
5 The exploitation of non-renewable sources
6 The newest electricity-powered products
3 Read the text again and answer the questions.
1 List some examples of renewable sources.
2 How can we produce energy from sunlight?
3 What are the main reasons for the decline of decline non-renewable sources?
vocabulary
4 Match the words (1-8) with their definitions (a-h). 1 demand 2 timber 3 livestock 4 harvest 5 plant 6 obsolete 7 replenished 8 exhaust writing
a sunlight to produce electricity. b the future of energy production. c are more energy-efficient. d can be used indefinitely. e which will never exhaust. f is meant to decline.
4 Why is timber considered a renewable resource?
5 Why was renewable energy seen as a ‘niche sector’?
6 What do significant levels of investments in renewable sources suggest?
a the crops that have been gathered b to put new supplies into something c to use all of something d the need or desire people have for particular goods e no longer useful because of new inventions f animals such as cows and sheep that are kept on a farm g a factory or a building where an industrial process happens h trees that produce wood to be used in building or making things
5 Write six short sentences using the words in exercise 4. The demand for nuclear energy is increasing nowadays.
You are a journalist for ‘The Green blog’. Your friend is an expert in the energy field. Ask him/her to help you write your next article about renewable energy sources: write questions about the various renewable alternatives, then compare their efficiency, pollution, costs. Then use the information to write your blog.
Increasing energy efficiency is one of the main ways to reach an affordable, reliable, sustainable and modern energy system, as stated by goal 7 of the 2030 Agenda. A modern energy system reduces consumption and costs, decreases energy dependency and decreases the environmental and climate impacts linked to energy supply and use.
While still relying heavily on fossil fuels for its energy, the European Union is set to increase its domestic energy production especially from renewable energy sources: doing so, it will decrease energy consumption, while building and updating infrastructure will grant clean energy in the whole EU.
1 Write under the pictures the names of the energy sources from the box, then say if they are renewable (R) or non-renewable (NR). biomass fossil fuels geothermal hydroelectric natural gas nuclear solar wind A B C D E F G H 2 Write the English equivalents for these words. 1 riscaldamento globale 2 combustibile 3 inquinamento 4 materia organica
5 ceneri 6 reagenti chimici 7 energia delle maree 8 biosfera 3 Underline the correct alternative.
1 Most of our energy is obtained from non-renewable / renewable energy sources. 2 Oil, natural gas and coal are fossil fuels / non-fossil fuels 3 Uranium is another solid / nuclear non-renewable element. 4 Uranium atoms create heat through a process called nuclear fusion / fission. 4 Complete the text with the words from the box. energy (x2) evaporates fuels hydroelectricity non-renewable renewable run out supply thousands
Non-renewable (1) is something that is being depleted, and at some point there will be none left. One kind of (2) resource is fossil fuels. Fossil (3) such as oil, coal and natural gas which are made from dead animals and vegetation remains from millions of years ago, take hundreds of (4) of years to be made. In a short time, fossil fuel will (5) because it is being used up too quickly. Oil is already in short (6) . (7) resources which can be used year after year, such as trees, water and solar (8) , can renew themselves quickly. It’s just like recycling paper. There is a confusion over the terms renewable resources and renewable sources of energy. All renewable sources of energy are also renewable resources. Water can become an energy called (9) . Water is a renewable resource as it keeps returning. As long as rain keeps falling on a country, it runs into the dams, into houses and then out again down to the sea, where it (10) up into the rain clouds. A renewable resource is always there and will never run out.
5 Complete the text about deforestation with the words from the box. agriculture climate deforestation emissions expansion minerals minute trees weather wood
6 Read the text about how a wind turbine works, and complete the picture with the missing words.
In the picture you can see the most common type of wind turbine, called horizontal axle. Wind turbines are large structures located on long poles with blades that produce electricity from wind power. The function of the blades is to collect the wind’s moving air or kinetic energy. The wind pushes the air and spins the blades of the wind turbines. The blades are connected to a drive shaft. The turning of the blades makes the shaft inside the turbine rotate, and the shaft set in motion the gears that are connected to the generator, making it spin. The spinning generator produces energy. So kinetic energy can be trapped to produce mechanical energy, which, in turn, produces electrical energy. The power cables inside the tower transfer the energy produced to a transformer, and then to the switchyard from where the energy is diverted to its final destination.
Forest wildfires, pest diseases, invasive species, drought and extreme (1) events are some of the reasons why every (2) we lose an area about 36 football fields of (3) Deforestation is also responsible for 13% of our yearly carbon (4) . All of these compounding issues are driven and amplified by (5) change. However, climate change is not the only cause of (6) . 85% of deforestation in the world is caused by industrial (7) due to meat production (especially beef), soy and palm oil. Timber logging due to the incredible demand for (8) and wood products and mining for the ever-increasing demand for (9) are additional causes of deforestation. Finally, large swaths of forest get cleared to make way for the (10) of cities and human settlements. 1 2 3 4 5 6
How it works
1In a graphical projection the image of a 3D object is projected:
A onto a planar surface. B onto a curved surface.
In most cases, a single view is not sufficient to show all necessary features.
To identify all the features of an object it is necessary to have different views or projections of it because an object is threedimensional and includes width, height and depth.
Graphical projection is the protocol used to represent a 3D object on a plane surface without including the mathematical calculations. It actually makes the study of design of an object or structure easier. Graphical projection has an important role in machine drawing and design.
width larghezza depth profondità sundials meridiane
Orthographic projections that show more than one side of an object.
A parallel projection (or axonometric projection) is a projection of an object in three-dimensional space onto a fixed plane. The lines of sight, or projection lines, from the object to the projection plane are parallel to each other. Its advantage is that it helps you to evaluate the object’s shape and size proportion without any distortion. It is a basic tool in descriptive geometry.
The projection is called orthographic if the lines of sight are perpendicular (orthogonal) to the image plane, and oblique if they are not.
In parallel projection, the lines of sight from the object to the projection plane are parallel to each other. Within parallel projection there is a subcategory known as pictorials.
Technical drawings do not show objects as they appear in photographs, because photographs do not indicate true dimensions. A technical drawing shows as many views of an object as it may be necessary to define its exact shape and size. The most common method of doing this is called orthographic projection.
Orthographic projection has been known since ancient times.
In about 14 BC, Roman engineer Marcus Vitruvius Pollio used the projection to construct sundials and to compute sun positions. Vitruvius also seems to have invented the term orthographic (from Greek orthos, straight and graph, drawing) for the projection.
The orthographic projection is a two-dimensional representation of a three-dimensional object. In the orthographic projection the object is viewed along parallel lines that are perpendicular to the plane of the drawing. Orthographic drawings include top views (plans), flat front and side views (elevations), and cross-sectional views showing profile.
In a drawing or painting the vanishing point is the point on the horizon where parallel lines seem to meet at a distance, giving the illusion of depth. When the set of parallel lines is perpendicular to a picture plane, the construction is known as one-point perspective, and their vanishing point corresponds to the oculus or eye point, from which the image should be viewed for correct perspective geometry. Traditional linear drawings use objects with one to three sets of parallels, defining one to three vanishing points.
vanishing point punto di fuga
One-point perspective projection.
reading comprehension
Double-point perspective projection. Three-point perspective projection.
2 Read the text and match the two parts of the sentences.
1 Graphical projection makes
2 Graphical projection
3 Axonometric projections
4 The term ortho means
5 An orthogonal projection is
6 Orthogonal projection has been known
3 CERT Read the text again and answer the questions.
a a two dimensional representation. b since the Roman times. c the study of the structure of an object easier. d are parallel projections. e plays a major role in machine drawing. f ‘straight’.
More about
1 Why does graphical projection make the study of design of an object easier?
2 Define a parallel projection.
3 How are the lines of sight from the object to the projection plane?
4 What do the Greek words ortho and graph mean?
5 How are the lines of sight in an orthogonal projection?
6 Who used projections to construct sundials?
writing
4 Do some research on the Internet about 3D printing, and write a short report about the latest developments that you find.
5 Watch this video about pictorial drawings and answer the questions.
1 What are pictorial drawings?
2 What do the words Cavalier and Cabinet refer to?
3 In which one does the image look a bit distorted?
4 In which one is the depth halved?
5 How many variations does perspective drawing have?
A pictorial is something illustrated or expressed in pictures; it is an essential part of graphic language. A pictorial drawing is the view of an object (actual or imagined) as it would be seen by an observer who looks at the object either in a chosen direction or from a selected point of view. It is a 3D representation of an object.
There are three types of pictorial views: perspective, isometric and oblique.
A draftsman/draftswoman, also called a drafter, is a person who specialises in creating technical drawings. Drafters draw pictures all day. They aren’t guided by a creative impulse but (0) from drafting firms, manufacturing plants, and construction companies. First they take the ideas, sketches and concepts from designers and then (1) for projects in many industries. Drafters start by (2) using such devices as compasses, T-squares and the like. Today, the most of them (3) and design systems or CAD. Modern computer technology has drastically changed the roles and responsibilities of their job. CAD programmes allow experts (4) that can easily be modified. Although CAD speeds up the working process, drafters still have (5) and symbols as well as the language standards and systems for the industry they work in. Communication and (6) are also important. Professionals usually work exclusively in a particular industry or discipline. A mechanical drafter, for example, (7) and their parts, while an electronics drafter might outline the schematics for electrical wires and currents within houses or consumer products; a civil drafter might work with engineers and surveyors to prepare land maps and design blueprints for buildings and other structures. Most of the main tasks of a drafter on a weekly or monthly basis are to check and (8) and the dimension of the object to be used; to modify and revise designs, to correct operating deficiencies or to reduce production problems and reproduce working drawings on copy machines.
C
1 INVALSI Read the text about the work of a drafter. Parts of the text have been removed. Choose the correct part (A-K) for each gap (1-8). There are two extra parts that you should not use. The first one (0) has been done for you. A to create highly accurate scale drawings B might draw diagrams for machines C by exacting specifications
D it is used in ships manufacturing E problem solving skills F being trained to draw by hand G Cad software can be used to design H to understand traditional drafting terms I use computer-aided drafting J determine the strength and quality of materials K turn them into detailed final working plans
DATE AND PLACE OF BIRTH 1908 – Natchez, Mississippi EDUCATION
MAIN WORKS
LITERARY ACHIEVEMENT
Fragmentary, due to extreme poverty
Uncle Tom’s Children; Native Son; Black Boy
His novels marked a new beginning in African American fiction. Wright refused to portray the stereotype of the black man who ‘knows his place’: he denounced and justified the hidden anger of black people caused by the limitations that society placed on African Americans.
– Paris
1 Read the fact file about Richard Wright and then, working in pair, give a short presentation of his life.
2 Read the text about the storyline of Black Boy and answer the questions.
Black Boy (A memoir)
Black Boy is the autobiography of Richard Wright’s hard years from 1912 to 1927, from the perspective of a child’s view. The story begins when four-year-old Richard sets fire to his grandmother’s house in Mississippi, and, as punishment, is nearly beaten to death by his mother. He recovers, and the brutal punishment gives Richard an ability to survive any circumstance. The family then moves to Memphis, Tennessee, where Richard’s father eventually deserts the family. Here, Richard learns about racism both from what he observes in the world and how his family members humiliate themselves in front of the whites. When his mother becomes ill, however, Richard moves with her back to Mississippi to live with his grandmother. By age 12, Richard has alienated himself from most of his family, which reinforces his role as an outsider – a role he later finds is shared by many American writers. Throughout the next several years, Richard excels at school but feels detached from his classmates because he behaves differently from other black children. After graduation and another failed period of time at a job, Richard steals the money to go North. With his stolen money he moves to Chicago. He realises that he will become a writer. Richard’s autobiography is continued in American Hunger, which was published nearly two decades after his death in 1960.
1 What is Black Boy about?
2 What does the author say about his experience with racism?
3 What makes of Richard an outsider?
3 Read this short extract from the book and answer the questions.
One winter morning in the long ago, four-year-old days of my life I found myself standing before a fireplace, warming my hands over a mound of glowing coals, listening to the wind whistle past the house outside. All morning my mother had been scolding me, telling me to keep still, warning me that I must make no noise. And I was angry, fretful, and impatient. In the next room Granny lay ill and under the day and night care of a doctor and I knew that I would be punished If I did not obey. I crossed restlessly to the window and pushed back the long fluffy white curtains – which I had been forbidden to touch – and looked yearningly out into the empty street. I was dreaming of running and playing and shouting, but the vivid image of Granny’s old, white, wrinkled, grim face, framed by a halo of tumbling black hair, lying upon a huge feather-pillow made me afraid. The house was quiet. Behind me, my brother, a year younger than me, was playing placidly upon the floor with a toy. A bird wheeled past the window and I greeted it with a glad shout. “You better hush,” my brother said. “You, shut up,” I said. My mother stepped briskly into the room and closed the door behind her. She came to me and shook her finger in my face. “You stop that yelling, you hear?” she whispered. “You know Granny’s sick and you better keep quiet!” I hung my head and sulked. She left and I ached with boredom. “I told you so,” my brother gloated. “You shut up,” I told him again. I wandered listlessly about the room, trying to think of something to do, dreading the return of my mother, resentful of being neglected.
The room held nothing of interest except the fire and finally I stood before the shimmering embers, fascinated by the quivering coals. An idea of a new kind of game grew and took root in my mind. Why not throw something into the fire and watch it burn? I looked about. There was only my picture book and my mother would beat me if I burned that. Then what? I hunted around until I saw the broom leaning in a closet. That’s it. [...] I pulled out the broom and tore out a batch of straws and tossed them into the fire and watched them smoke, turn black, blaze, and finally become white wisps of ghosts that vanished. [...] My brother came to my side, his eyes drawn by the blazing straws. “Don’t do that,” he said. “How come?” I asked. He said “You’ll burn the whole broom,”. “You, hush,” I said. “I’ll tell,” he said. “And I’ll hit you,” I said. My idea was growing, blooming. Now I was wondering just how the long fluffy white curtains would look if I lit a bunch of straw and held it under them. Would I try it? Sure. I pulled several straws from the broom and held them to the fire until they blazed. I went to the window and brought the flame in touch with the hems of the curtains. My brother shook his head. “No,” he said. He spoke too late. Red circles were eating into the white cloth then a flare of flames shot out. Startled, I backed away. The fire soared to the ceiling. Soon a sheet of yellow lit the room. I was terrified, I wanted to scream but was afraid. I looked around for my brother; he was gone. One half of the room was now ablaze. Smoke was choking me and the fire was licking at my face, making me gasp.
2 What brilliant idea crosses his mind? 3 What are the consequences of his game?
critical thinking
“Whenever my environment had failed to support or nourish me, I had clutched at books.”
Richard Wright’s life in the storyline of Black Boy provides several interesting, thought-inspiring topics such as:
• racism: the book was written in a period where racial hatred was very prominent in American society.
• education (the one thing that cannot be stolen from a person)
• identity crisis and isolation
• poverty/dehumanization
had been scolding aveva rimproverato wrinkled rugosa broom scopa straws fili di paglia hems orli flare bagliore ablaze in fiamme was choking mi stava soffocando
writing 1 Choose one of the topics above and write an essay of about 200 words.
2 Read your essay to the class and listen to your classmates’ contributions.
my mine mio, mia, miei, mie your yours tuo, tua, tuoi, tue his his suo, sua, suoi, sue (di lui) her hers suo, sua, suoi, sue (di lei) its suo, sua, suoi, sue (di cosa) our ours nostro, nostra, nostri, nostre your yours vostro, vostra, vostri, vostre their theirs loro
L’aggettivo possessivo
• è invariabile, precede sempre il nome a cui è riferito e rifiuta sempre l’articolo:
My bike needs new rubber tyres. Our lab coat is white. Their science lesson is finished.
• alla terza persona singolare concorda con il possessore e non con la cosa posseduta:
Brian has just rebooted his computer. Susan told me about her new job. We are studying steel and its properties.
Gli aggetti possessivi sono invariabili rispetto al genere e al numero, hanno cioè la stessa forma sia per il maschile che per il femminile, sia per il singolare che per il plurale: Your dad and your sisters are waiting for you, hurry yp! My sisters are in the same class with your brothers.
Il pronome possessivo sostituisce un nome, non è mai preceduto dall’articolo, e alla terza persona singolare si accorda con il nome del possessore:
That red backpack belongs to Tom, it’s his The Kevlar hiking boots belong to Ann, they’re hers.
1 Underline the correct alternative.
1 That red screwdriver is my / mine.
2 This is my / mine plastic bag. Where is you / yours?
3 Look, this is Mary’s new toolbox: it’s her / hers toolbox.
4 No, this isn’t Mary’s toolbox, it belongs to Tom, it’s his / its toolbox.
5 Give the new welders their / theirs welding screens.
6 Look at our / ours new iron gate.
2 Complete the sentences with the correct possessive adjective.
1 favourite lesson is Information Technology. (Amanda)
2 birthday is on Saturday. (I)
3 metallurgy exam is tomorrow. (Liz and I)
4 best friend is called Matt. (Jake)
5 house is very big. (Rachel and David)
6 workshop is enormous! (my school)
3 Translate these sentences into English.
1 Non riesco a trovare il mio caschetto, posso usare il tuo?
2 Ho ricevuto il CV di Mike, ma manca la sua lettera di presentazione. .
3 La loro casa è completamente automatizzata; vuoi automatizzare la tua? .
4 La mia macchina non parte: la sua batteria è scarica.
5 Mia sorella e i suoi amici stanno per iniziare un corso di CAD; il mio è appena finito. .
6 Questo tornio è troppo vecchio per essere aggiustato: i suoi costi di utilizzo sono troppo elevati. .
Per esprimere relazioni familiari e l’idea del possesso si usa una costruzione chiamata possessive case (genitivo sassone). Il possessive case si forma aggiungendo ’s al nome del possessore, seguito dalla cosa o persona posseduta senza articolo.
possessore + ’s + cosa o persona posseduta Our designer’s projects are among the four finalists. Sarah’s father is a skilled machinist.
Quando due persone possiedono qualcosa insieme si aggiunge ’s alla seconda persona: This is Dan and Holly’s workshop.
Se il nome del possessore è un plurale o un nome che termina in s, si mette solo ’: Our designers’ project is among the four finalists.
Quello, quella di non si traducono:
My screwdriver is new, Benny’s is old.
Anche se di regola il possessore è una persona, ci sono alcune espressioni riferite a cose che richiedono questa costruzione. Le più comuni sono:
• espressioni di tempo e misura: Yesterday’s mechanical check failed.
• nomi di città e nazioni: Turin’s car industry is one of the most renowned.
• alcune espressioni di uso corrente: At a stone’s throw. (molto vicino)
1 Rewrite the sentences adding the possessive form (’s or ’) in the sentences.
1 The workers new helmets are yellow.
2 Bob and Roger tools are in the second drawer. .
3 The firms lawyers found an agreement. .
4 Hannah and Kathryn new jobs are in two different cities.
5 The board accepted yesterday project. .
6 Luis interview is tomorrow morning. .
1 Decide if these statements below are true (T) or false (F).
1 Traditional methods of drawing are useless in our technological age.
2 Using software sharpens the abilities for visual details.
3 Rapidograph is the brand of a specialised pen for technical drawing.
4 The disadvantage of a stencil is that it can’t be re-used.
5 Most technical drawings require a thick and a light line.
6 The thick line is used for hatching.
7 Orthographic projection has been known since Roman times.
8 The term ‘orthographic’ comes from Latin.
9 In orthographic projection the object is viewed along curved lines.
10 The effect of perspective projection is that distant objects appear bigger than nearer objects.
11 Vanishing point is the point where lines appear to converge.
12 Isometric means same measure.
13 Isometric projection represents two-dimensional objects in three dimensions.
14 CAD allows designers to create two or three dimensional shapes.
15 A pictorial drawing is a 3D representation of an object.
16 There are two types of pictorial view.
17 Pictorial drawing is an essential part of graphic language.
18 Rendering means computer-generated graphics.
19 Render is the resulting image of the process of rendering.
20 Technical drawing is ambiguous.
2 Complete the text about CAD with the words from the box.
angle animation applications costs design hardware interface machinery rotations two-dimensional
CAD software allows the use of computer technology for the development of (1) and design documentation. It is used to design curves and figures in (2) space, or curves, surfaces and solids in 3D objects. CAD has a great number of (3) : automotive, shipbuilding and aerospace industries, industrial design of tools and (4) , architectural design, prosthetics and also computer (5) for special effects in movies and advertising. The objects and features created can be changed to make them suitable for different purposes. Modern CAD can also allow (6) in 3D so that the designed object can be viewed from any (7) . Nowadays, CAD systems exist for all major platforms and no special (8) is required for most CAD software. The humanmachine (9) is usually via a computer mouse or a pen and a digitising or graphics tablet. The advantages of CAD are lower product development (10) and a much shorter design cycle.
1 In small groups, search the internet and choose two examples of technical and artistic drawings. Add drawings or photos taken from the internet.
2 Gather information and write a text describing the similarities and differences between the two drawings.
3 Assemble the material and prepare your contribution to be shown in class.
• competenza multilinguistica
• competenza digitale
• competenza personale, sociale e capacità di imparare a imparare
• competenza in materia di cittadinanza
• competenza imprenditoriale
• competenza in materia di consapevolezza ed espressione culturali
21st-Century Life Skills
• Senso critico
• Creatività
• Decision-making
• Comunicazione efficace
There are three types of axonometric projections: isometric, dimetric and trimetric. Isometric projections, when the object is positioned in such a way that all its sides are equally distant from the axes, and the axes have a command angle of 120° each.
Diametric projections are like the isometric ones, but the direction of viewing is such that two of the three axes of the object appear equally foreshortened.
In Trimetric projections the direction of viewing is such that all of the three axes appear unequally spaced.
1 width a asse
2 height b rimpicciolito
3 depth c larghezza
4 foreshortened d vista
5 axes e altezza
6 sight f profondità
23 23 ASCOLTA e LEGGI il brano sulla prospettiva e DECIDI se le affermazioni che seguono sono vere (T) o false (F).
Perspective projection is a linear projection in which 3D objects are projected onto a picture plane. This has the effect that distant objects appear smaller than nearer objects. Besides, lines which are parallel in nature appear to intersect in the projected image. The single point where lines appear to converge is called vanishing point. Perspective drawing, which presents a realistic illusion of space, uses a horizon line and vanishing points to show how objects and spatial relationships might appear to the eye.
1 Perspective projection is a linear projection.
2 The effect produced by this projection is to make appear distant objects bigger.
3 In the projected image lines appear to intersect.
4 Perspective drawing gives a realistic view of space.
5 The vanishing point is where the lines appear to converge.
6 To show how objects can appear, perspective uses a horizon line and vanishing points.
PARALLEL
axonometric
4
24 COMPLETA il grafico con le parole del riquadro. isometric • dimetric • trimetric • perspectives CAD 25 24 ASCOLTA e LEGGI questo brano su Computer-aided design.
1 2 3
There are two types of computer-aided design systems used for the production of technical drawing. The first, called 2D CAD, may be used to design curves and figures in two-dimensional space on an electronic drawing tablet (or board), along with a drawing stylus. Its strength is in the making of revisions: while, in case of errors or edits, a new drawing on paper must be made from scratch, the 2D CAD allows a copy of the original to be modified. The second, called 3D CAD, is used to design curves, surfaces and solids in three-dimensional space. This software produces the geometry of the part, while the user defines the views of the part of the technical drawing. Any orthographic view is created by the software, there is no possibility of error. Both 2D and 3D CAD systems can be used to produce technical drawings for any discipline. The process of using a computer software to generate an image from 2D or 3D modelling, both a realistic or non-realistic one, is known as rendering, and the resulting image is called the render. Rendering software is mostly used in architecture, video games, movies and visual effects.
1 What are the main types of CAD systems?
2 Why has 2D replaced the paper drawing?
3 What does 3D produce?
4 What is the function of the user in 3D system?
5 What is rendering?
6 What is a render?
a It produces the geometry of the part.
b It is the generation of an image from 2D or 3D modelling through a software.
c 2D and 3D CAD
d The image resulting from the rendering process.
e Because it is much better in the making of revisions.
f The technical drawing of the user defines the views of the part.