Quads VS Tiangles

Modelling with Quads or Triangles What Should I Use?

As a modeler, you’ve probably already encountered your own internal debate on using quads or tris? The truth is, while it can come down to preference, there are some key advantages to using quads to create your models.

It’s also not the end of the world – or your model – if you use both, but it is recommended to use as few triangles as possible to save you some major headaches down the line. Let’s cover why quads are so beneficial for your work.

Understanding Different types of polygones

Triangles

Triangle is the simplist polygon that is made up of 3 sides or edges connected by 3 vertices, making a 3 sided face. When modeling, triangles are typically a polygon type often avoided.

Tringles tend to pose a problem when subdividing geometry to increase resolution and when a mesh will be deformed or animated.

Quadrilaterals

A quad is a polygon made up of four sides or edges that are connected by four vertices, making a four sided face. Quads are the polygon type that you will want to strive for when creating 3D models.

Quads will ensure your mesh has clean topology and that your model will deform properly when animated.

N-Gon

An n-gon is a polygon that is made up of five or more sides or edges connected by five or more vertices. It's important to keep in mind an n-gon is typically related to a five sided polygon, but it's not just limited to five sides.

An n-gon should always be avoided, they often pose problems at render time, when texturing and especially when deforming for animation.

So why choose quads?

When modeling with quads, the wireframe will have a much cleaner look and the model will be easier to navigate and edit. When you spend hours working on a project, you deserve to show it off, but if the wireframe is messy you become very limited to what you can put out in the world.

When you use quads you create clean, sleek lanes of polygons that are easy to follow through the model and provide beautiful edge flows that can be easily modified by you or a team member. Someone can convert a model made up of quads to triangles easier than converting a model made up of triangles to quads. Having clean polygons also makes for a less distracting wireframe that you may want to overlay onto a clay shaded model or even a textured asset.

Edge Loops

Edge loops are typically a continuous loop with no determined start or end point. If you were to follow a loop from a highlighted vertex, you would eventually end up at that exact vertex. Edge loops are helpful to add detail such as wrinkles or folds, they can also be used to help define how sharp an edge is.

If an edge loop runs into a triangle, the loop has to end. This breaks the flow of the line and it’s no longer a loop.

Sculpting

So you want to add that extra little detail to your model, you better use quads. If you plan on taking your model into a sculpting application, such as ZBrush or Mudbox, it is best to avoid triangles as much as possible.

Sometimes you may need to subdivide the geometry 4-5 times pushing your model to over a million polygons. This is why you want to work with a predictable quad- based mesh. This also helps build a lower resolution version and accent the model using edge loops.

Subdividing

When subdividing quads, your results are fairly predictable. You have rows and columns made up of four sided polygons and it is easy to see where those polygons will be split in half once it is subdivided.

When you subdivide triangles, things tend to get messy. There really isn’t a visual flow to the model.

Smoothing

If you plan on smoothing your geometry or using a quick smooth preview feature, triangles will produce anomalies across the surface of the mesh. Because of the uneven amount of vertices, the triangle can cause blemishes or pinch the geometry. This similar thing can happen to geometry created with n-gons.

Animation

Quads produce cleaner deformations. Typically, artists will focus on areas where there will be a lot of bending and deforming, such as knees, elbows and wrists, and provide a little extra geometry that will benefit the rig and animation. With quads, this is easily accomplished by adding or manipulating edge loops.

If you have a cluster of triangles in this area, it is harder to add or remove loops that will help benefit the animator. With triangles, it is also harder to see a clean flow of geometry and they tend to produce sharp angles that can harm the mesh’s appeal. When it comes to animation appeal is important both to the model and the artist who provided the mesh for animation

What about hard surface models?

When modeling hard surface models, the preference is still to use quads. The main reason: so you can quickly add and remove edge loops. When it comes to UV mapping your model, it is also easier when using quads. There are less edges to clutter the texture editor when placing UVs.

Triangles are not a bad thing. They just have to be used strategically throughout your model. When using them on organic models, it is best to hide triangles where they will not be visible or in areas where very few deformations are happening.

A good thing to keep in mind when working in quads is you can always convert it to triangles. There will be times when triangles will be preferred, an example of this is the final mesh of game assets or characters. In these instances most artists still prefer to work in quads and then convert their final model to a mesh built of triangles.

Page updated

Report abuse