There are two ways of projecting objects, namely parallel projections and central projections, where I have discussed in the article “2 Ways to Project Objects or Objects“. In this discussion we will review the definition of projections and the types of projection techniques based on the position and method. Here are our brief, clear and straightforward reviews.
According to Luzadder, the notion of projection techniques or drawing images is often called orthographic images, namely the projection of two or more faces to explain objects carefully in their shape and size. This projection technique image requires careful imagination. Because of this, this image is often used by reliable engineers, drawers, and contractors, because they know more about graphic images.
Projection Technique :
Image projection techniques can be divided into 4 types, namely :
1. Projection perspective (Scenographic)
In perspective projection, the projection line (visual radial line) meets in a point (convergent). It is as if we are staring at a projected image on a translucent paper, where the image is the same shape as the real object behind the transparent paper. The size of the image depends on how far the observer is with the actual object. Consider the following picture.
In this way, some argue that this perspective projection is not properly used for a working picture, because it is considered not to provide a definite measure. Therefore, the projection image is more often used as an introduction to an initial sketch.
2. Parallel Projection (Orthographic)
This projection has similarities with perspective projections. However, in looking at images and real objects that are behind them in a parallel position, so that it looks like the size. Consider the following picture.
3. One-field projection (Inclined Projection)
Projection of one field is a way to see some changes or inclinations (intentionally done) of object projectors in the image plane. This projection is a special type of orthographic projection known as the axonometric projection form. Consider the following picture.
In addition to the form of axonometrics, the projection of one field is also known as oblique projection. At first glance it looks similar or parallel like an axonometric projection, but the sloping projection forms take another angle of 900 with the projection plane so that the results seen in the image area will look different, depending on which angle we see or depend on the angle the projector is made with projection field. More details, note the following picture.
4. First corner projection and third angle
This projection is like arranging three glass pieces. Two glass pieces in a standing position cross like a + sign, and some with a horizontal position in the middle which will eventually divide up space and lower space.
Thus, four fields are formed which are distinguished as the first, second, third, and fourth angles. The lines that exactly form the intersection are called coordinate axes. The point of intersection is called the starting point. Consider the following picture.
In using the first angular projection and the third angle, what must be remembered is that with the angle however the object is placed, the observer looks at it from the front of the plane and from the top of the horizontal plane.