Select Page
Introduction to 3D Modeling and Animation
Class 04: Topology

Topics

    • Topology
    • Deformation
    • Basic Sculpting
    • Week 04 Character Head Model Lab

This is class fore!

Topology

Topology

Topology refers to the geometric surface characteristics of a 3D object. Good topology support the three-dimensional form and ample deformation.

Gridflow

Gridflow refers to the regular/irregular path of edge loops across the surface of a three-dimensional objects.
You are looking for a regular clean flow of edges (not zig-zagging) that work perpendicular to each other (typically horizontal & vertical).

Deformation

Deformation

Deformation in a model refers to its ability to distort its shape. You must model your character to be able to bend, flex, twist, and so on depending on the areas of articulation.

Common Geometrical Errors

Non-Manifold Geometry

Non-manifold topology polygons have a configuration that cannot be unfolded into a continuous flat piece. Some tools and actions in Maya cannot work properly with non-manifold geometry. For example, the Boolean operations and the Reduce feature do not work with non-manifold polygon topology. The image below shows three examples of non-manifold topology polygons.

Lamina Faces

Lamina faces share all of their edges. Basically, one face “on top” of the other, usually sharing edges.
One common cause is extruding faces but not translating them after.

Non-Planar Surfaces

A polygon face is planar when all of its vertices lie in a certain plane. For example, a triangle face is always planar, because its three points define a plane.
A polygon face is non-planar when it has more than three vertices, and one or more of those vertices do not lie in the same plane. When a polygon mesh is comprised of quads or n-gons it is possible to have non-planar polygon faces.

Floating Vertices

Be careful about have random floating vertices.
Deleting edges but not the vertices are a common mistake.

Poles/Stars

Poles are areas where more than four edges meet and result in poor contiguous surfaces.

Dense or Sparse Geometry

Your objects should only have the necessary about of geometry needed to complete the form.

Non-Contour

If the geometry does not “wrap around the surface it will look incorrect and not deform appropriately.

Non Square

You are looking for square geometry where possible.
Square geometry will model, texture, and deform better than non-square geometry.
That being said you also want to limit your total polycount.

Basic Sculpting

3D Sculpting:

You could break down 3D modeling into two major categories; hard-surface and character.

Hard-surface modeling generally entails modeling items with “hard” surfaces (go figure). This mean man-made objects, like houses, vehicles, furniture, etc. They are often very similar to primitive forms so manually creating polygons in a CAD-like way makes sense. This is the type of modeling we have done thus far.

Character modeling involves modeling characters (surprise!). These are organic dynamic soft forms like humans, animals, plants, and other natural objects. These are best created using something that is fluid and freeform, like sculpting. This is often a good area for more traditional artists to flex their muscles.

The window to the right shows a good example of a mechanical hard-surface model vs an organic soft-surface model.

Zbrush Core Mini

Pixologic Zbrush has become an industry standard in digital sculpting. It is however a paid program. It is also very complicated (not as much as Maya but still pretty bad). Pixologic offers a free “lower-grade” version of their program called, Zbrush Core Mini. It does not have all the bells and whistles but does allow for Dynamesh Sculpt.

Dynamesh is process of sculpting on a mesh and the model auto-generates the geometry necessary for the change to the surface to happen. Basically it automatically will subdivide the model as you sculpt. This is very free-form and you do not need to worry about the geometry of the model at all while you work, just the aesthetics of the form.

Click this link to download ZBrush Core Mini

 

Retopology

Retopology is the process of creating a model with proper grid-flow on top of a reference model with poor geometry. This allows you to create an aesthetically pleasing model without concern of the geometry itself. Then you can simply use it as a guide to create a similar form but with proper topology.

Week 04 Character Head Model Lab

Week 04 Character Head Model Lab:

The character’s body is complete but he lacks a head. In this lab we will put a head on its shoulders.

You will be graded on the following:
  • Reference Accuracy
    • The model closely resembles the reference turnaround images.
  • Geometry
    • Produce a clean mesh with few errors.
  • Topology
    • Strong gridflow that supports the form well.
  • Aesthetic
    • Excellent design that is appealing to look at.
Resources:
Assignment Video Tutorials
You may watch these tutorial videos below to help you complete your assignment.
Assignment Lab Materials
You may download the lab materials here: 3Dweek04LabMaterials.

Assignment Video Tutorials

Wait! Before you go!

Did you remember to?

  • Read through this webpage
  • Watch the videos
  • Submit Week 04 Character Head Model Lab on Blackboard