Intro To Models

Intro To Models for Unreal Engine 4 - Page 1

Unreal gives you access to brushes where you can craft the roughing out of a level that is sometimes refered to as "gray blocking". This is where a designer lays out the level and figures out the gameplay before it goes to an art team to properly model and create assets.

Otter dancing with a fish

You will need to install the latest version of UE4 4.25.x by downloading the Epic Games Launcher. You will also need a GitHub account which is free to sign up for as we will be using version control. You will also need a mac or PC that is powerful enough to run unreal. If you are on a PC you will have to download and install git (on a mac it may prompt you to install git as well but you can do it through the terminal). We will also install Github Desktop as it provides a GUI interface so you don't have to worry about command line. Once git is installed you will also need to download and install the Git LFS (Large File System) as well for both PC and mac. You will also need access to Maya 2020..

Lets make sure you can see hidden folders. On the PC follow these Windows 10 Turn on Hidden Folders directions. On the Mac it is a bit more involved so go and turn on hidden folders on Mac.

1. Anatomy of a 3-D Model

Lets look at the some terminology and what it means for a 3-D Model.


Install all Software

UE4's models need consist of polygons. It will not take models that are made with NURBS or other surface types. A polygon is a plane that has at least three lines that connect to form a closed shape.

The best format to take into Unreal is the FBX format. Most 3-D software will allow you to export your model as polygons in the FBX format. This is a proprietary format that is used by most software but is owned by Autodesk.


Polygonal face

Lets look at the simplest polygon a face. Here it is displayed in Maya 2019. It is the area within the edges covering the arean of the plane.



A polygon is made up on vertices, edges and faces. Lets look at a vertice. It is an X, Y, Z point in 3-D Space. So a plane consists of 4 vertices. They all connect to each other to form a closed shape.



So this plane consists of 4 Edges. Every pair of vertices contains one edge. Multiple edges can share the same vertice. So these 4 edges just have 4 vertices as each one is used twice.



Every group of edges that form a closed polygon is called a face:



Now even on a single plane, it can contain multiple faces. If we divide this one plane up into a 4 by 4 grid. We get 16 planes. Make sure you have no faces made up of more than 4 lines. These Ngons (N stands for any number greater than 4) will be problematic in Unreal.



Now a quad (4 vertices for a polygon) is two triangles (3 vertice polygon sometimes refered to as "tris"). For Unreal it will eventually take anything into triangles so you can use quads or triangles with little issues.


Face Normals

Now lets look at some hidden attributes that you don't see but are very important to how surfaces are displayed. Each face has a normal which is a perpendicular line to the tangent plane of the surface. The normal is used for determining the surface's orientation for lighting.


Vertex Normal

A vertex normal has the normals from all adjacent faces. This way the renderer can figure out where the edge lies for lighting and shading.


Vertex Normal Alteration

These vertex normals can be adjusted to behave differently without adding geometry to the model. In 3D Studio Max is is called Smoothing Groups. In Maya you can affect the surface normals by softening the edge of the vertex normals on a face.


Different Edge Types

This takes an average of the three vertex normals and softens the edge. This will be exported and viewable in UE4.