Projections
Understanding Projections in Geometry
Projections
- A projection is a way of representing a three-dimensional figure on a two-dimensional plane.
- There are three main types of projections: perspective projections, orthographic projections and oblique projections.
Types of Projections
Perspective Projections
- Perspective projections depict objects as they would appear to the human eye or a camera lens.
- As objects get further away in a perspective projection, they appear smaller. This projection includes vanishing points.
- Parallel lines in perspective projection appear to converge at a distant point.
Orthographic Projections
- Orthographic projections represent objects by projecting the details of the 3D object onto a 2D surface. They maintain the relative proportions of the object.
- This represents an object as exactly front-on, top-down or side-on, commonly used in technical and engineering drawings.
- A set of orthographic projects includes the plan (top view), front view/ elevation and side view.
Oblique Projections
- Unlike orthographic projections, oblique projections provide a way to produce a two-dimensional drawing of a three-dimensional object which gives a better overall picture of the object.
- It includes the front face in regular proportion, but the depth can be drawn at any angle.
Working with Projections
- To sketch a 3D projection, it is best to start with the closest side to the viewer (often the front) and then add the other dimensions.
- In a full set of projections, every edge should appear in at least two views, and every point in at least three views.
- Understanding how to interpret and draw these projections is a crucial skill in architectural, engineering, and several other technical disciplines.
Understanding the principles of projections can aid in recognizing the properties of three-dimensional objects and how they can be represented in two dimensions. Practice drawing and interpreting different types of projections to improve your understanding and skills.