Understanding Object Views: Orthogonal Projections Explained
Understanding Object Views
The main view is called an object, the orthogonal projections of the same on 6 planes, arranged in a cube. We can also define views as the orthogonal projections of an object, according to the different directions from where you look.
Views of an Object
If we place an observer according to the six directions indicated by the arrows, we get six possible views of an object:
- View A: Front view or elevation
- View B: Top view or plan
- View C: Right or right lateral view
- View D: Left or left lateral view
- View E: Bottom view
- View F: Rear view
Relative Positions of the Views
For the provision of different views on paper, you can use two orthogonal projection variants of the same importance:
- The method of projecting the first dihedral, also called the European (ISO E)
- The third method of projecting the dihedral, also called American (ISO A)
European System (ISO E)
It is used in almost every country of the world. This system is based on the projections of the body being made in the first dihedral planes, which are opaque.
The elements constituting the projection are formed by the source, body, and projection plane (the unit of measurement is mm).
American System (ISO A)
This projection is based on considering the body in the third dihedral, which is transparent. The flat elements of this projection are formed as a focus, projection plane, and body (the measurement unit is the inch).
Projections
Projections can be defined as a projection figure that results from projecting, on a flat surface, all points on the boundary of a solid or another figure. It has three key elements:
- Center of projection
- Plane projection
- Lines of projection
Different Types of Projections
Conics: The center of projection has a fixed position and is determined.
Cylindrical: The center of projection is at infinity. The cylindrical projection may be:
- Orthogonal: Projecting rays form an angle of 90 degrees with the plane projecting.
- Oblique: Rays projecting at an angle other than 90 degrees to the plane of projection.
Diédrico System
It is the precursor of all systems and the wider field of applications, especially in industry and civil works. It is also the most widespread of all known dual-projection systems, or Monge, this being the first French geometer who compiled it. It is a system of orthogonal cylindrical projections, i.e., that it is used only the orthogonal projection. This type of projection is the most commonly used in Technical Drawing.
It maintained relations of parallelism and in those dimensions that are parallel to the axes, also remain proportionality true shape and true scale.
In the Diédrico System, projections are made on planes perpendicular projection (horizontal and vertical plane) dividing the space into four quadrants as shown in the figure below.