Geometry - Introduction 

Triangle and Polygon Usage

Level of Detail

Additional Geometry Best Practices

Demo: Level of Detail

This project will highlight optimizations for 3D models that can make a game more efficient while maintaining aesthetic intent, improving the performance and experience on mobile devices. 

Geometry

Course Introduction

The Optimization Process

Profiling Tools

Textures - Introduction

Texture Size, Color Space, and Compression

Texture Atlases

Texture Filtering

Mipmapping

UV Unwrap, Visual Impact, and Texture Channel Packing

Alpha Channels and Normal Map Best Practices

Editing Texture Settings

Demo: Texture Atlases

Shaders and Materials - Overview

Optimizing Shaders for Mobile Platforms

Transparencies

Additional Material and Shader Best Practices

Demo: Draw Calls and SRP Batcher

Lighting - Overview

Light Modes and Types

Lighting for Static Objects

Light Probes

Shadows

Demo: Baked Lighting

Conclusion/Next Steps

Welcome to 3D Art Optimization for Mobile Applications! In this introductory project, we will review the course's main learning objectives, discuss the practice of optimization, and identify the optimization tools available at your disposal.

Introduction/Optimization and Profiling

This project will highlight the different implementation considerations and optimizations that take advantage of a Texture’s flexibility. When given the correct settings and applied correctly over their many use cases, Textures play a major role in achieving your desired visual effects. 

Textures

Shaders and Materials play a crucial role in determining how target hardware will process and render your 3D objects. In this project, you will explore best practices that will keep the shaders lightweight and fast when running on phones with limited resources.

Shaders and Materials

Lighting is one of the most important aspects of real-time 3D visuals. It can set the mood, guide interactions, and identify goals and objectives. In this project, you will learn about and compare the differences between the available lights and light modes that you can use in your 3D mobile application.

Lighting

ARMUnityMobileOptimization.zip

In this intermediate course, participants will learn how to produce performance-optimized 3D assets and scenes for mobile applications. Topics will cover tips on optimizing Geometry, Textures, Materials, Shaders, and Lighting. This course was created with technical artists and content creators in mind.

Arm & Unity Presents: 3D Art Optimization for Mobile Applications

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Overview

Smoothing Groups

Mesh Topology

Shape Exaggeration

Combining Meshes

Model Settings

Conclusion

This tutorial examines additional best practices when prioritizing optimization while working with geometry in your mobile application.

Along with suggestions from the previous tutorials, there are several things to keep in mind when creating your models. The following recommendations aren’t specific to any one 3D content creation tool and can be used across projects.  

Use smoothing groups, or custom vertex normals, to define an edge’s hardness and alter the look of a model. Smoothing groups help create better shading when the art direction intentionally uses a tiny polygon count.

Take extra care, as smoothing groups affect a model’s UV islands — basically chunks of the model — and the quality of a normal map when you do baking.

If smoothing is implemented on a 3D model, then it must be exported from the 3D software and imported into Unity.

The following image shows how smoothing works when applied to an object:

Remember these tips when using Mesh topology:

When creating a 3D Asset, keep the topology reasonably tidy and clean.

Clean topology is essential for characters and objects that are deforming or animated.

Don’t obsess over having perfect topology. The player, or end user, won’t see the wireframe of a 3D model once you’ve applied a Texture and Material.

The following image shows a wireframe of a rocky cliff Mesh that uses simple geometry and topology. The cliff looks much better once a Material has been applied. 

Shape exaggeration involves making certain parts of an object bigger than normal to help with readability. Whether this is the right approach for your game depends on the style of game you are creating.

A mobile device screen is small, meaning it can be difficult to capture certain shapes if they’re tiny. Exaggerating a shape helps to overcome this. For example, make a character’s hands larger so they’re easier to see on a small screen.

The following image shows how an exaggerated hand might look. The hand, sword, and body proportions are all emphasized in different ways. This was done to improve the visibility while taking the lower polygon count into consideration:

To reduce the number of draw calls required for rendering, you can combine several Meshes into one with the Mesh.CombineMeshes() method. If the Meshes all share the same Material, set the mergeSubMeshes argument to true so that it generates a single sub-Mesh from each Mesh in the combined group. 

Combining several Meshes into one larger mesh helps:

Turn tile-based Assets into a large, seamless solid Asset.

Create an empty GameObject in the Hierarchy and make it the parent of the Meshes that you want to combine.

Attach a script implementing Mesh.CombineMeshes() onto the parent GameObject.

Depending on the makeup of your Scene, implementing this method can be useful for performance optimization. Large Meshes tend to stay in view longer than smaller Meshes, so experiment to get the correct size.

Don’t import animation data on FBX Mesh models that do not animate: When importing an FBX Mesh that doesn’t contain any animation data, set Animation Type to None in the Rig tab of the Import Settings. When you place your Mesh into the Hierarchy, this setting will ensure Unity doesn’t generate an unused Animator component.

Avoid Read/Write Meshes: If your model is modified at runtime, Unity keeps a copy of the Mesh data in memory to modify while preserving the original. If your model is not modified at runtime, disable the Read/Write Enabled option from the Model tab of the Import Settings to prevent a copy from being created.

Static/Dynamic Batching: Static Batching is a common optimization technique that reduces the number of draw calls. It’s ideal for objects made up of a large number of vertices that don’t move, rotate, or scale during rendering. To enable Static Batching, check Static in the Inspector containing the Mesh Renderer of your target model. Built-in Dynamic Batching occurs for objects with fewer but similar vertices sharing the same Material. Refer to the documentation to learn more about further criteria necessary for meshes to implement Dynamic Batching.

Optimizing Mesh topology, combining Meshes, exaggerating shapes and configuring model settings are all techniques that can be used to increase application performance. In the next tutorial, we’ll explore LOD techniques in an example Unity project. 

Additional Geometry Best Practices

1. Overview

2. Smoothing Groups

3. Mesh Topology

4. Shape Exaggeration

5. Combining Meshes

6. Model Settings

7. Conclusion

Complete this tutorial