There are two main types of projection in 3D modeling: parallel and perspective. In this blog post, we’ll take a look at the difference between these two types of projection, and when you might want to use each one.
What is Parallel Projection?
Parallel projection is a type of projection where the projected image is a parallel, or non-converging, projection of the scene. Parallel projection is typically used for technical drawings, such as blueprints, where it is important to maintain the correct dimensions and relationships between objects. Perspective projection is a type of projection that simulates how we see objects in the real world.
Perspective projection involves drawing images on a flat surface so that they appear to recede into the distance. This type of projection is often used in art and photography to create a sense of depth and distance. While both parallel and perspective projection have their uses, perspective projection is typically more realistic and easier for viewers to understand.
What is Perspective Projection?
Perspective projection is the name given to a particular mapping of 3D points onto a 2D plane. It is commonly used in computer graphics, and in particular 3D games, to give the illusion of depth on a flat screen.
- To create a perspective projection, we first need to define a so-called “viewing volume”. This is basically a cube (or rectangular prism) within which all objects that we want to project must lie. We then define a point called the “center of projection”, which is typically somewhere near the middle of this viewing volume.
- All Perspective projections will contain this point. Now, imagine drawing a line from each vertex of the viewing volume (i.e. each corner of the cube) through to the center of projection.
- These lines will intersect the 2D plane at different points, and it is these points that we map our 3D vertices onto. The result is an image that appears to have depth, as objects that are closer to the center of projection appear larger than those that are further away.
Perspective projection is just one way in which we can map 3D points onto a 2D surface. Other common methods include orthographic projection and oblique projection. Each has its own advantages and disadvantages, and so the choice of mapping method depends on the specific application.
Difference between Parallel and Perspective Projection
- Parallel projection is a type of projection where the projected image is a parallel, or non-converging, projection of the scene. Parallel projection is typically used for technical drawings, such as blueprints, where it is important to maintain the correct dimensions and relationships between objects.
- Perspective projection is a type of projection that simulates how we see objects in the real world. Perspective projection involves drawing images on a flat surface so that they appear to recede into the distance.
- This type of projection is often used in art and photography to create a sense of depth and distance. While both parallel and perspective projection have their uses, perspective projection is typically more realistic and easier for viewers to understand.
Conclusion
In this blog post, we’ve taken a look at the differences between parallel and perspective projection. We’ve seen how each method can be used to create different effects in an image. Next time you need to create an illustration or just want to change up your photos, keep these concepts in mind.
