In our continuing series of CGI basics, we look at the Bridge function
Get a thorough understanding of the Bridge function
If you’re new to CGI there are far too many tools to choose from in a dizzying array of software. This series aims to break everything in CGI down to the very basics, so that every artist can be armed with the knowledge of which tool is best. This time we are looking at the Bridge function.
Bridge is one of the most helpful functions in a 3D artist’s arsenal. It is a hugely versatile function that can create the foundations for a complex build, or create curved and twisted geometry all by itself with a single click of the mouse.
One of the key things that using Bridge teaches is the concept of surface normal direction on a polygon. While polygons (or faces) may appear to be a 3D shape, a polygon only has one ‘true’ side, and the normal denotes the perpendicular direction the polygon is facing. This matters when using the Bridge tool, as bridging two polygons facing the wrong direction can create unpredictable results, and make using the Bridge tool a disappointing experience for new users.
The Bridge tool has the power to radically change your geometry by removing polygons at the ends of bridge segments, so make sure you are aware of all the options that the Bridge tool has in each piece of 3D software.
These options can include factors such as twisting, and making a curved bridge, as opposed to a linear one.
Some apps can use the Bridge command to create polygons from vertices, which is a powerful way to remesh geometry. When working with meshes using Sub-division methods, like Open Subdiv, mastering the Bridge tool is a good way to get to grips with complex shapes. For example, creating a basic arm between a wrist and shoulder model.
Certain 3D applications can allow multiple elements to be bridged with one click, which enables complex and organic models to be created easily.
The Bridge tool is a versatile command that takes a lot of the pain out of 3D modelling.
Author Mike Griggs Mike Griggs is a 3D and visual effects artist with vast experience across the industry, as both a creator and a technical writer. www.creativebloke.com