Triangles or Quads For Video Games?

Let’s start by looking at the basic shapes of polygons used with 3d modeling:

polygons

Triangles are made up of 3 sides which meet at the corners (called vertices). Quads are made of 4 sides. You can see in the above image how every shape can be broken down into smaller triangles.

ngon

Ngon example

There is also what is call an ngon, which is used to refer to a polygon made of more than 4 sides and has not been divided into triangles or quads. Ngons are not acceptable for games.

What to use:

Since all surfaces are automatically broken down into triangles in the game engine anyway which should you model with?

tri-to-quad

Dividing a triangle into quads.

Edge flow on organic models is important when you go to animate them to avoid problems with deformation. In these instances quads are preferred and should give you better results.

Additionally with programs that subdivide your model many times, such as Zbrush, quads will give you cleaner results because of the way triangles are subdivided.

eye-good-edge-flow

Good edge flow around an rhino’s eye.

On low poly (like those used in games) or hard surface (e.g. a table) models, modeling with triangles is perfectly acceptable. Just make sure that you have good edge flow where there will be joints so that during animation the model deforms properly!

Once your model goes into the game the cost of that model will largely come down to how many triangles (commonly referred to as tris) the model is divided into, so plan wisely!

Comparison of silhouettes based on triangles used.

Comparison of silhouettes based on triangles used. Source