# What Is A Projection Line?

## What is projection and its type?

Projection are defined as mapping of three-dimensional points to a two-dimensional plane.

There are two type of projection parallel and perspective.

1.

Parallel Projection use to display picture in its true shape and size.

When projectors are perpendicular to view plane then is called orthographic projection..

## What is projection of a point?

The projection of a point is its shadow on the paper sheet. The shadow of a point on the paper sheet is this point itself (idempotency). … The projection parallel to a direction D, onto a plane or parallel projection: The image of a point P is the intersection with the plane of the line parallel to D passing through P.

## What is 1st angle of projection?

First angle projection is a method of creating a 2D drawing of a 3D object. It is mainly used in Europe and Asia and has not been officially used in Australia for many years. In Australia, third angle projection is the preferred method of orthographic projection. Note the symbol for first angle orthographic projection.

## What is VP and HP?

VP: The plane in front of observer is the vertical plane. (VP) or it is also called a Frontal plane. … HP: The plane which is Horizontal and perpendicular to VP is Horizontal Plane. Top View (TV): The projection on the HP is called the Top View (TV) or Horizontal Projection or Plan.

## How do you project a vector?

The vector projection of b onto a is the vector with this length that begins at the point A points in the same direction (or opposite direction if the scalar projection is negative) as a. This quantity is also called the component of b in the a direction (hence the notation comp).

## What is projection line in civil engineering?

The figure or view formed by joining, in correct sequence, the points at which these lines meet the plane is called the Projection of the object. The lines or rays drawn from the object to the plane are called Projectors. The transparent plane on which the projections are drawn is known as Plane of Projection.

## What is projection line in engineering drawing?

PROJECTION OF LINES SH 1132 Engineering Graphics F.Y. B. Tech. CLASS B: Line parallel to (or in) one reference plane & inclined to other two planes (1) Line parallel to ( or in) V.P. & inclined to H.P. by . (2) Line parallel to ( or in) H.P. & inclined to V.P. by .

## What is the meaning of projection?

When you push something away from a central structure, that’s called projection. Both the ject in projection and the word jet come from the Latin root jactus, which means “throw.” A jet plane throws itself — or projects itself — away from a central structure (the Earth) and into the air. …

## What are the 3 planes of projection?

[FIGURE 3-2] Projections of the point are made onto three of the surfaces that make up the box: the top or “H” (horizontal) plane, the front or “F” (frontal) plane, and the right side or “P” (profile) plane.

## What are the types of projections?

Projection Methods Used In Mechanical DrawingOrthographic Projection. Orthographic projection shows a 3D object in two dimensions so that you can see three views: the front view, side view and top view. … Axonometric Projection. Axonometric is another type of orthographic projection. … Oblique Projection. … Perspective Projection.

## How do you find the projection of a line?

If a line is perpendicular to a plane, its projection is a point. The intersection point with the plane and its direction vector s will be coincident with the normal vector N of the plane. If a line is parallel with a plane then it will be parallel with its projection onto the plane.

## When a point is above HP and behind VP The point is resting in?

Explanation: The position of reference planes will be similar to quadrants in x, y plane co-ordinate system. As the 2nd quadrant lies above the x-axis and behind the y-axis here also the 2nd quadrant is above H.P, behind V.P.

## What are the two main types of projection?

There are two main types of projection:1)Parallel and Convergent2)Perspective and Parallel3)Parallel and Orthographic4)Station-point and Perspective5)NULL