Good Topology: What is it, and Why Does it Matter? 

So far in my 3D education, the most difficult thing has been understanding the whole workflow end to end. There are so many differently workflows and topology requirements can be very different for each. It would be great to explain the workflow implications for each of the common topology types. For example, game dev low poly workflow, game dev character workflow, VFX deformation/explosion workflow, etc.

we need it asap,thanks for the vid

Yes please! A series tackling different model of different styles and proportions for animation would be massive!

Yes, havent been able to find a good one that starts from the bottom and explains theory to work to complex things.

Yep, it seems that there's so much misunderstanding about topology once you scratch the surface.

Glad it was helpful!

I think what you say is important to consider and understand. I’m new to this and I was looking at a model with all quads in blender that seemed to have way more geometry than the faces would initially seem to allow. Upon closer inspection, I realized that the quad faces can, as you imply here, be 3D. To help me visualize this I had to think about a flat square, then if I move opposing vertices in opposite directions - eg two opposing corners go up or the two other go down - that’s like folding the square into two triangles that are not co-planar. However, there’s no combination of vertex moving that will make the triangle be anything but co-planar.

@@JayM928 Precisely :) Something else to note is that most engines convert 4+ polygons back down to tris when rendering. This isn't a problem when the quads are coplanar, but there are two ways to make two triangles from one quad and they can produce drastically different shapes leading to unpredictable behavior (never a good thing)

Quads can be bent into non-parallel shapes, yes. But that usually isn't the case, at least by default.

Well, just throw in Suzanne and you'll find plenty but ok.

@@DECODEDVFX A quad is just a polygon with 4 edges, aka a quadrilateral. It's very easy to make a quadrilateral with no parallel edges out of a square. Just take one of the vertices and move it to or away from the opposite corner vertex by any amount.

typology

That's exactly what topology is: a mathematical representation of edge flow, by drawing lines across a surface, which is traditionally done in an interval grid to create quads.

@@locinolacolino1302 In my college days, we did do drafting by hand to understand engineering drawings so we can present CAD models properly. What did we use? Grid paper.

I've also been told one of the benefits of quads is that they can bend along either of their diagonals, which can make animations less prone to artifacts. My understanding this allows a rendering engine to pick the best diagonal to triangulate on at runtime, so it can take better advantage of dynamic deformations. If you're working with a triangulated mesh, your diagonals are fixed, so they may be at odds with the angle a face should deform to follow a rig.

The vast majority of problems concern shading, because when you import the model as fbx or obj, the mesh gets automatically triangulated. Quad modelling rarely gives shading problems because a plane (face) is perfectly split into two triangles, on the other hand, vertices in ngons faces try to algoritmically reach other vertices to form triangles, basically distorting the mesh' s shading. I know you already know all that, this comment was more for the benefit of people reading this in the future. Cheeerssss

Try cube modeling or Retopoflow. it often is done by a machine.

The time benefit is mainly observed later down a studio pipeline, good topology is easier to unwrap, texture, simulate, shape-key, results in less lighting glitches. But as a one man band just go with whatever works.

@@locinolacolino1302 Depends. In most cases, the "Good topology" adds no benefit at all, especially if the model never leaves blender...

With quad topology you can easily create lods, however I think ngons are much easier to manage in order to reduce the polycount.

​@@gabrielegagliardi3956 Game engines will automatically split NGons into tris upon import. Feel free to triangulate in Blender to see the model how the Game Engine does.

Thanks!

Convert to tris. Remesh. Decimate.

@@DECODEDVFX Flip a few normals and split corners while your at it 😂😂

Most quads have at least two sides which are parallel or close to parallel.

When the lines are not parallel they instead follow the contours of the object usually. The lines concept still holds up even if they are not all perfectly parallel/perpendicular. I'm sure you are thinking of loops around the lips or ears on a face model or other unusual organic shapes, but the general flow of the face still has lines that flow upward and left to right, or across the contours, maintaining the continuity with the loop of faces its connected to. Correct me if I'm Wrong anywhere @DECODEDVFX

You still at the very minimum want to be able to use modifiers with pretty much any of your meshes

@@bobross9370 I'd argue that depends on the scene. The model is just there to fill out the shot? Then it really doesn't matter how well it plays with any modifier other than maybe decimate.

@@demian5631 It sounds like you may not understand why quad topology is important. It doesn't take that much more time to model with correct topology than it does to do a jank/crap job once you have the principles down and you've had some practice. The main difference? Other people can use/manipulate the model, it will work with modifiers, simulation and animations, you don't spend time fanangling or fixing/hiding errors later when things go wrong. Professionals don't really tolerate bad topology in many instances in the industry and in the end you'll understand and learn that even though your ego may think you're better than the decades of experience others have spent learning how to 3D model more efficiently, you'll eventually realize that Auto-Smooth Shading isn't your savior. Modeling and mesh principles are still the same as they were when we first started. Which means the mesh topology rules and guides are probably not obsolete! I don't want to discourage you, as I have gone through the stage where I thought I was better than I was, but it took some humility to realize that my cutting of corners was just wasting my time in the long run. Do it right and you'll do well.

@@demian5631 Pretty much what the other guy said, modelling quads is not hard at all, you could even do a lazy method on background objects with a quad remesh so long as it's workable topology. If you ever try to take 3D seriously, you will very quickly find out how important quad topology is. Modifiers matter a lot, it's best to have your options open on every model rather as struggle one at a time.

​@@bobross9370 If a model really needed it, then I would load the model up in instant meshes. Gives much better results than Blender's built in remeshers. My point wasn't that you should never care, it's knowing when to care. You are hired at a studio and have to work with others? Make sure the topology is at least decent. You are working on a project entirely by yourself with little time and no money and the object in question is out of focus and 10px big? Who cares! I've used alpha masked images as backfill before and no one has called me out on it yet. Spent your time wisely is my point.

This is a good example and helps me understand better. A lot of people talk about this topic from “professional” perspective, and all I really care about as someone just doodling around is “ok, but how much does it really matter?” The code example makes much more sense to me. There are times where it matters immensely, and times where it doesn’t matter at all. It depends on end goals, what you’ll use it for, does speed of execution matter, is there any reuse, are others going to need to be able to read it or modify it, is it a side project, is it a professional product, etc etc.

Mathematics and Modeling - like any very specialized field - have their own specialized terms. And sometimes they don't match up. Naming is hard!

I'm not exactly sure where you're coming from, but in the world of 3D modeling topology refers to the way the geometry of the model is structured, including the placement and flow of vertices, edges, and faces.