As a result, the earths poles and landmasses closest to them are distorted. Projection of straight lines ii line geometry angle. The gnomonic map projection in the image is centered on the north pole with meridians radiating out as straight lines. In standard presentation, conic or conical projections map meridians as straight lines, and parallels as arcs of circles. On a mercator projection map, any rhumb line is a straight line.
Projection of straight lines part1 by subhodaya video3 youtube. Like the cylindrical projection, conic map projections have parallels that cross the meridians at right angles with a constant measure of distortion throughout. Projection of a straight line of a plane definition of. Projection of straight lines in engineering graphics pdf. Other meridians are curves or possibly straight from pole to equator, regularly spaced along parallels. Pseudocylindrical projections map parallels as straight lines. Different surfaces and planes form the configuration or shape of any object.
Scale decreases along all lines radiating from center point of projection. Both the meridians and parallels are expanded at the same ratio with increased latitude. As on the lambert conformal projection on which it is based, the earth is developed by means of a conic projection. Projection of straight lines ii free download as powerpoint presentation. Along parallels, each point from the surface is mapped at a distance from the central. The end a is 12 mm in front of the vp and 15 mm above hp. To estimate evenly spaced, and regularly increasing, rents or other revenues from a project,although reality may be a little more irregular. In standard presentation, these map the central meridian and parallels as straight lines. The projection is defined on the entire sphere, except at one point. Straight line basis is a method of calculating depreciation and amortization. Straight line is also the shortest distance between any two given points. Despite their usefulness for navigation, rhumb lines do not show the shortest distance between two points.
If straight lines are drawn from various points on the contour of an object to meet a plane, the object is said to be projected on that plane. A straight line may have different orientations in space well be positioning this line in different ways that is it may be parallel or inclined to. Pseudocylindrical projections represent the central meridian as a straight line segment. P when reduced length and angle are given, line parallel to one plane and inclined to. Graphical projection methods rely on the duality between lines and points, whereby two straight lines determine a point while two points determine a straight line. Are all of the lines of latitude parallel to each other on both the globe and the mercator projection. Projections of straight lines pdf book manual free.
These maps show lines of latitude as parallel straight lines and lines of longitude as nonparallel lines that become increasingly curved as you move farther away from the maps central meridian. Basic engineering drawing projection knowledge zone, the. An imaginary line that is used to locate or project the corners, edges, and features of a three. Projections of straight line when inclined to both hp and. Firstly the vertical lines are guarented to stay straight for any r. Engineering drawing projection of straight lines, telugu video lecture line parallel to h. Projection of lines a straight line is the shortest distance between two points. Since the projection is from the centre of the sphere, a gnomonic map can represent less than half of the area of the sphere. The mercator projection is a plane conformal projection and is not perspective this projection is the most often use in navigation. Mar 14, 2017 projection of lines sh 12 engineering graphics f. A line is a geometric primitive that has length and direction, but no thickness. When do straight lines become curved when talking about projection. Sep 27, 2017 projection of straight lines telugu lecture. The mercator projection is a cylindrical projection that was developed for navigation purposes.
Thats why greenland looks bigger than south america. Where it is defined, the mapping is smooth and bijective. Expressing a projection on to a line as a matrix vector prod. This is a projection where the lines of latitude and longitude are projected as straight lines at 90 degrees to each other.
Mar 14, 2020 projections of straight lines ppt, engineering drawing, semester mechanical engineering notes edurev is made by best teachers of mechanical engineering. Secondly, the lines going through the center of the screen are guarented to stay straight as well for any r. The location of a line in projection quadrants is described by specifying the distances of its end points from the vp, hp and pp. Projection of a line onto a plane,intersection point of. If a given line is perpendicular to a plane, its projection is a point, that is the intersection point with the plane, and its direction vector s is coincident with the normal vector n of the plane. Angles become distorted moving away from the equator. The projections of a line measures 80mmin the top viewand 70 mminthe front view.
Mercator projection, a map projection introduced by flemish cartographer gerardus mercator in 1569. Projections of straight lines straight line it is the shortest distance between two given points. Projection of straight lines part1 by subhodaya video3. Here is an example problem for drawing the orthographic views for a straight line when inclined to both principal planes. The panini projection bring severals guarentees on the lines. Line, cross, point lasers for positioning tasks lap. Nov 12, 2016 in this tutorial, the object is a straight line. The mercator projection was used for its portrayal of direction and shape, so it was helpful to the sailors of that time. The simplest position a straight line occupies in a space is, it is parallel to both v. Straight lines projection civil engineering drawing questions and. Other meridians are longer than the central meridian and bow outward, away from the central meridian.
The higher the power, the longer the line will be brighter than the environment and thus remain visible. A straight line ab of 40 mm length has one of its ends a, at 10 mm from the hp and 15 mm from the vp. On this channel you can get education and knowledge for general issues and topics. The lines of latitude are horizontal straight lines, perpendicular to the meridians and the same.
A straight line is the shortest distancebetween two points. Projection of straight lines, situated in first quadrant only, inclined to both horizontal and vertical planes location of traces only. Draw the projections of the line if it is parallel to the vp and inclined at 30 to the hp. Top views of two end points of a straight line, when joined, give the top view of the straight line. A projection, i always imagine, is if you had some light source that were perpendicular somehow or orthogonal to our line so lets say our light source was shining down like this, and im doing that direction because that is perpendicular to my line, i imagine the projection of x onto this line.
In geometry, the stereographic projection is a particular mapping that projects a sphere onto a plane. Start studying ied 2 technical sketching and drawing. A straight line 55 mm long makes an angle of 30 deg to the hp and 45 deg to the vp. Ied 2 technical sketching and drawing flashcards quizlet. Straight line locus of a point, which moves linearly the shortest distance between any two given points.
The vector projection of a vector a on or onto a nonzero vector b also known as the vector component or vector resolution of a in the direction of b is the orthogonal projection of a onto a straight line parallel to b. Determination of true length and true inclinations of straight lines from the projections not involving traces projection of plane surfaces like rectangle, square, pentagon, hexagon, circle surfaces inclined to one reference plane. The subsections below describe the mercator projection properties. Also known as straight line depreciation, it is the simplest way to work out the loss of value of an asset over time. The final subsection completely generalizes projection, orthogonal or not. The explanation is the easiest way to understand the engineering drawinggraphics subject. When you decide what type of projection you wish to use. Then decide the view which will give us the true length of the line and true inclination. Study 68 terms basics of map projections flashcards. This projection has minor, but not major, distortions.
Projection of straight lines in engineering graphics pdf in engineering drawing practice two principal planes are used to get the. The observer moves back to pole c and pole d is reset in line with c and b see fig. Projection of straight lines and planes first angle brainkart. Projections in engineering drawing my tutorial world. Great circles plot as straight lines on the lambert conformal projection. However the concept of orthographic projections must be known to thoroughly understand it. Our recent energy survey revealed that straightline projections are the most common energy budgeting technique in commercial real estate. The maximum distance for getting a sharp line, crosshair or point is about 30 m. Rotating line method and rotating trapezoidal method. Straight line is the locus of a point, which moves linearly. Orthogonal projection of a straight line if a straight line p is not a ray of projection not perpendicular to either projection plane, then its horizontal and vertical projections are lines p and p. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Projections of straight linesdefinition of straight line.
The figure formed by joining, in correct sequence, the points at which these lines meet the plane, is called the projection of the object. Sep 20, 2008 projections of straight lines mid point problem posted on september 20, 2008 25 comments straightlinemidpointsolution click this link power point slide showto see the illustration of mid point problem. To create a straightline projection, managers simply copy last years actual bills over to next year, optionally applying an adjustment. Perspective projection a method of projection in which a threedimensional object can be represented by projecting points upon a picture plane using. Engineering graphics projection of points and lines. All books are in clear copy here, and all files are secure so dont worry about it. Cylindrical projections represent meridians as straight, evenlyspaced, vertical lines and parallels as straight horizontal lines. Projection of straight lines link for projection of points. Ground rules for projection of straight lines slideshare. Tips for projection of straight linesiiinclined to both.
These straight lines are then often plotted on a map with the mercator projection for use in navigation because it follows true compass directions and is, therefore, useful in such a setting. This is the projection of choice because on these maps the arc of a great circle is depicted as a straight line. When a line is parallel to or it is contained by the hp, its top view is equal in. Directions are true from the center point north pole. Lesson 2 projections of straight lines part ii slideshare. The mid point of theline is 45 mmin front ofvpand 35 mm above hp. Projection of straight lines and planes first angle. The figure formed by joining various points thus obtained on the plane, is the image of the object and is called projection. Front views of the two end points of a straight line, when joined, give the front view of the straight line. Projection of a line onto a plane orthogonal projection of a line onto a plane is a line or a point. Conic in standard presentation, conic or conical projections map meridians as straight lines, and parallels as arcs of circles. The straight lines crossing at right angles of this map projection make it useful for navigation, but it distorts. Projection of a line study material for iit jee askiitians.
When a projection preserves great circle routes as straight lines, we call it an azimuthal projection. These lines are the same as in the mercator above, but the projection changes their appearance. In the graph,a the dark columns shows a straight line projection for apartment leaseup over the course of the year. The location of a line in projection quadrants is described by specifying the distances of. Projection of straight lines a straight line is the shortest distance between the two.
Any straight line drawn on a map based on a mercator projection is a rhumb line. It is also used for calibrating a map in the shareware version or in the registered version if the true projection is not known. Any straight line through center point is a great circle. Perspective projection article about perspective projection. Here are some typical examination questions on chart projections. Now the straight line is the great circle, and the curved one is the loxodrome. Whereas on the azimuthal equidistant projection only straight lines that originate at the maps central point show greatcircle arcs, the gnomonic projection has no such limitation. Projections of straight lines ppt, engineering drawing. A flat surface on which a straight line joining any two points would wholly lie. Revolving or moving straight lines in different ways obtains these surfaces and planes. For obtaining the image of an object, various points on the contour of an object, are thrown forward on to a plane by means of straight lines or visual rays. Hence, in monges projection, a straight line is represented by a pair of projections p,p.
On a northsouth passage the rhumb line course coincides with a great circle, as it does on an eastwest passage along the equator. Great circles transform to straight lines via the gnomonic projection. Sep 11, 2007 tips for projection of straight lines iiinclined to both planes posted on september 11. When we use equalarea projection maps is because we want to have the true size of the features. Expressing a projection on to a line as a matrix vector. Straight line depreciation is the most commonly used and easiest method for allocating depreciation of an asset. It is a form of parallel projection, where all the projection lines are orthogonal to the projection plane, resulting in every plane of the scene appearing in affine transformation on the viewing. A straight line is the shortest distance between two points. Grasp the concepts of projection of a line including projection line definition and straight line projection with the help of study material for iitjee by askiitians. In the last video we saw that if we had some line that was defined as all of the scalar multiples of some vector ill just write it like this. Parallel to one plane and perpendicular to the other. For any other position first assume the given line parallel to both the planes. What are projection lines in technical drawing answers.
This document is highly rated by mechanical engineering students and has been viewed 3270 times. Land area is more accurate than on a mercator projection. The meridians are vertical lines, parallel to each other, and equally spaced, and they extend to infinity when approaching the poles. Since meridians lines of longitude and the equator are great circles, they are always shown as straight lines on a gnomonic map. Location of a line the location of a line in projection quadrants is described by specifying the distances of its end points from the vp, hp and pp. Straightline is the shortest route to bad budgets gridium. The orthogonal projection of the eye point onto the picture plane is called the principal vanishing point p. Download projections of straight lines book pdf free download link or read online here in pdf. Pseudoconical in standard presentation, pseudoconical projections represent the central meridian as a straight line, other meridians as complex curves, and parallels as circular arcs. A straight line is also the shortest distance between any two given points.
The above position resulting in straight line as a top view and front view. The projections of a straight line are obtained by joining the top and front views of. Rhumb line in the mercator projection rhumb line in the mercator projection. In gnomonic maps great circles are displayed as straight lines. The next subsection shows how the definition of orthogonal projection onto a line gives us a way to calculate especially convienent bases for vector spaces, again something that is common in applications. In its basic form, a cylindrical surface touches the globe along a line called a tangent. Directions are true only from center point of projection.
To keep longitude lines straight and maintain the 90 angle between the latitude and longitude lines, the mercator projection uses varying distances between latitude lines away from the equator. After a certain distance, lines and points can no longer be focused. Projection of straight lines part1 by subhodaya video. The parallels of latitude and the meridians of longitude are all straight lines on the mercator projection. Projections of straight lines ppt, engineering drawing, semester mechanical engineering notes edurev notes for mechanical engineering is made by best teachers who have written some of the best books of mechanical engineering. A line cd 80 mm long is inclined at an angle of 300 to the h. The lines from the object to the plane are called projectors. Read online projections of straight lines book pdf free download link book now. The statements that describe equalarea projection are the following.
In the graph,a the dark columns shows a straightline projection for apartment leaseup over the course of the year. Projection of lines projection of intersecting lines when the lines are intersecting, the point of intersection lies on both the lines and hence these lines have no shortest distance between them. This video depicts the methodology of drawing projection of straight lines i using autocad. Thank u sir for projection of lines inclined to both the refrence planes. Projections of a straight line kept inclined to both hp and vp. Aug 06, 2019 these meridians are equidistant and straight lines which converge in locations along the projection regardless of if theres a pole or not. Assume the line to be located in each of the four quadrants by turns. The mercator projection is a useful navigation tool, as a straight line on a mercator map indicates a straight course, but it is not a practical world map, because of distortion of scale near the poles. A method of projection in which a threedimensional object can be represented by projecting points upon a picture plane using straight lines converging at a fixed point, representing the eye of the viewer. Rhumb lines and loxodromes facilitate navigation, as navigators prefer to follow a straight line route on the map and set their compass direction accordingly.
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