Difference Between Orthographic and Isometric Projection

Projection is a computer graphics system in which an image is shown in various dimensions. This helps to view 3D images into their 2D counterparts. Projection can be of two types which include Orthographic and Isometric Projection. In this article, we will discuss the difference between Orthographic and Isometric Projections.

What is Orthographic Projection?

Orthographic projection is a type of projection in which the projection and view plane are perpendicular to each other. Orthographic projection is a method in which 3D objects are converted into 2D objects and displayed on the screen. Projectors are arranged parallel to each other and they are also perpendicular. This type of projection is called multi-view projection.

Views of Orthographic Projection

There are three views of orthographic projection which include ?

• Front view
• Top view
• Side view

What is Isometric Projection?

Isometric projection is a type of projection in which an object is projected with all its three dimensions. This helps in the measurements of all sizes of an object easily. The same scale factor is used to measure two principal axes. The third axis is measured by different scale factors.

Drawing Terminology

The terminology used in a drawing is as follows.

• Drafting ? Drafting is a method of drawing in which a design is conveyed with the help of technical fields.
• Annotate ? Annotate is a method in which notes or labels are used in a drawing.
• Guidelines ? Guidelines are the lines which are used to add letters. These guidelines are not printed on paper.
• Construction Lines ? Construction lines are temporary lines which are used for guides.
• Hidden Lines ? Hidden lines are the lines represented in dashes. These lines are used for showing the edges of a hidden surface.
• Dimensions ? Dimensions can be of different types like
  • Radial
  • Linear
  • Arc
  • Ordinate
  • Angular

Difference between Orthographic and Isometric Projection

The table below shows the difference between Orthographic and Isometric Projections.

Which is better: Orthographic Projection or Isometric Projection?

Orthographic projection is a type of projection in which a 2D view of a 3D object is shown. In this type of projection, the projectors are arranged parallel to each other and the view plane is perpendicular to each other. Isometric projection is a type of projection in which all three faces of an object can be viewed.

Conclusion

Projection is a method of showing graphics on a screen through one or more projectors. Orthographic and Isometric are two types of projections which are used to project images. Orthographic projection converts a 3D image into a 2D image while Isometric projection shows all three sides of an image. There are many more differences and users have to use any of these projection methods to display the object.

FAQs on Orthographic Vs. Isometric Projection

1. Which projection type displays a 2D image of an object?

The orthographic projection shows the 2D image of an object. Isometric projection shows the 3D image of an object.

2. In which type of projection, the direction of the projection is perpendicular to the view plane?

In orthographic projection, the direction of the projection is perpendicular to the view plane.

3. Which type of projection has the ability to preserve distances and angles?

Distances and angles can be preserved in orthographic projection.

4. Why real images are not visible in orthographic projection?

Real images are not clearly visible in the orthographic projection because of the presence of hidden lines.

5. Which projection is useful for rectangular shapes?

Isometric projection is useful for the rectangular shape. The depth and shape of the image are distorted in isometric projection.