projections of straight lines parallel to both HP and VP are discussed in this video. Theory of projections, orthographic projections of points, videos are uploaded. Let's see what are straight lines. Straight line is defined as the shortest distance between any two points.
The other two points are considered as point A and point B. These two points are the shortest distance between straight line and line. Projections of straight line means projections of these end points, end point A and end point B. So, the projection of line AB, orthographic projection means the projection of the end point of this line AB. We have already discussed the projection of points.
We know the orthographic projection of points. Therefore, we can easily understand the projection of straight lines. That is, the projection of the end points of that line. Position of a line with respect to reference planes.
Let's see. Reference planes HP and VP. With respect to HP and VP, let's see how a line is positioned.
The projection of the line in those different positions is the projection of straight lines. First, we have to learn. First one, line parallel to both HP and VP. Second, a vertical line. Two cases and a line.
perpendicular to HP and parallel to VP line perpendicular to VP and parallel to HP third position line inclined to HP and parallel to VP line inclined to VP and parallel to HP finally line inclined to both HP and VP in this example point of view this is the fifth position important that is line is inclined to both HP and VP. Line is inclined to both horizontal plane and a vertical plane. Line in the e 4 positions um clear I want to slack you all e 5th position other the line inclined to both HP and VP will put in manasalakan but he video discussing the first position other the line parallel to both horizontal plane and vertical plane.
Line AB parallel to both HP and VP. Here we can see that distance from HP to A and distance from HP to B is the same. That means line parallel to HP. Horizontal plane is parallel to this line. Similarly, line parallel to VP.
in the a local a infant distance um we peel in the end a be like a la infant distance in same honor I'll angle we peel in the E line lay any point like Allah perpendicular distance they might honor very mother a port you line parallel to VP a he positional align in the projection honor number order discuss a friend view infinity in the front in the view Gable A is the visual race passing through A and B is the pass through B. When it strikes in VP, the front view of A is A', and the front view of B is B'. As discussed earlier, the front view is A'B'. For top view, The points that meet in HP, passing through visual rays A and B, the top view of A is a, and the top view of B is b, thus the top view is in HP.
The height from reference line XY to A dash, from A to a, all these will be same. That is, in that figure, a dash o1 equal to aa will be there. That is, in the front view, this above distance is seen here. The distance from HP to NdA is seen here. To locate that, this projector will be drawn perpendicular to the reference line and when the above distance from HP to A is marked, front view a dash will be obtained.
Same height is the length of bb, which is equal to the distance from hb to b. Both these are equal because the line is parallel to hb. Similarly, in the top view, the length of O1a, i.e. the in front distance, is equal to the distance from vp to O1a.
In front distance. Vp from point B to the in front distance. These will be the same. When the plane is rotated. First quadrant is opened.
That is when the HP is rotated down. Let us see how the orthographic projection of it comes. For that we will consider a question.
A straight line AB 60 mm long is parallel to both HP and Vp. the point is 30 mm above HP and 20 mm in front of EP. E distance equal to 30 mm. E above distance equal to 30 mm.
E in front distance equal to 20 mm. Parallel to both HP and VP, let us look at the orthographic projection of this line. From reference line, XY. First projector is on the left side.
We know that A dash is 30 mm above. The reference line is 30 mm above. That is, this distance is equal to 30 mm.
A dash can be located. In front distance, that is, from VP to A, this in front distance is equal to 20 mm. This is the problem. Therefore, in front below the X-ray line is the top view.
The X-ray line below. The Infront Distance is equal to 20 mm. Length of the line is equal to 60 mm.
Therefore, Length of AB is equal to 60 mm. Since the line is parallel to VP, the Front View of A dash and B dash is equal to 60 mm. The Infront Distance is same as the above distance. When A dash and B dash join, Front View is obtained.
When AB is joined, top view get to a dash b dash um same length i reckon random this is so you would align parallel to both hp and vp hp like lower projection top view vp like lower position front view random rule and the area observe with the gariam front view and top view both are parallel to x y and both those true length Let's see how this problem is manually drawn. Let's see how this problem is manually drawn. Let's see the question again.
A straight line AB 60 mm long is parallel to both HP and VP. A straight line AB 60 mm long is parallel to both HP and VP. The point A is 30 mm above HP and 20 mm in front of VP. Draw its projection.
The point A is 30 mm above HP and 20 mm in front of VP. Draw its projection. tannery another other either HP in the NDA local distance 30 mm tannery you know line parallel to HP at the wonder it's feeling the NDB like Allah you distance of 30 then you're you are they well a in front distance to a from VPS 20 mm and are the regular other the e distance it when deanna therefore NDB like a distance of 20 then I think any even their projection knock on friend view in failure in the front view will be Vp projectors will be A'A'B'B'line is parallel to Vp so front view will be true length therefore this line will be 60mm this height is above distance from HP which is equal to 30mm probably So, to draw the top view, when viewed from the top of infinity, the top view is formed in HP.
The inference distance is 20 mm. Since the line is parallel to HP, the length of top view, true length and 60mm will be the length of A and B. To draw the projections of this, first draw the reference line X, Y using thin line.
The probability given is that end A is 30mm above HP and 20mm in front of EP. Locate the position of A. Note the given data. 30mm above HP. that means above xy line a 20 mm in front that is 20 mm below xy line true length equal to 60 mm 30 mm above it a dash locating 20 mm in front rather 20 mm below xy line a locatia a dash a projector line in line use it very cute I'm a carry on The end of the line is B, which is in the same above distance.
Therefore, B'will also be in the same above distance. The length of the line is 60 mm. Since the line is parallel to VP, the front view will get true length. Therefore, we can draw a-b'thick line using 60 mm. Similarly, the top view is also true length.
60 mm xy line parallel same infinite distance of view thick line use very good b dash b projector line thin line use is very good projection complete i dimension Definition of straight line, projection of straight line, position of straight lines with respect to principal planes. This video will discuss it. What are they?
First position that is line parallel to both HP and VP. Detailed I will discuss it. Next video will discuss another. Projection of vertical line. First case line perpendicular to HP and parallel to VP.
Second case line perpendicular to VP and parallel to HP. Thank you for watching. Please like, share and subscribe.
Doubts and anything comment below.