Lighting - Overview

Light Modes and Types

Lighting for Static Objects

Light Probes

Shadows

Demo: Baked Lighting

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

Course Introduction

The Optimization Process

Profiling Tools

Geometry - Introduction 

Triangle and Polygon Usage

Level of Detail

Additional Geometry Best Practices

Demo: Level of Detail

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

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

Geometry

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

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.

2019.4

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

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Implementing Fake Shadows

Mesh Renderer Settings

Conclusion

In this tutorial, we discuss alternate ways of implementing and optimizing shadows.

Real shadows are computationally expensive to render. We recommend that you implement fake shadows on dynamic objects instead of resorting to dynamic lights.

Real-time shadows are most often generated using a technique known as a shadow map. The cost of Scene geometry being rendered to the shadow map is comparable to the number of vertices that are drawn to it. Because of this cost, it’s important to limit the amount of shadow-casting geometry, as well as the amount of real-time shadow-casting lights, in your Scene.

Here are some ways to implement fake shadows:

Use a 3D Mesh, plane, or quad that is placed under the character and apply a blurred Texture to it.

Write custom Shaders to create more sophisticated blob shadows.

The following screenshot shows shadow implementation using shadow Meshes.

It’s a good practice to paint lighting information directly to Textures. Doing this reduces the extra computation that real-time lights require. Painted lighting also saves memory when baking the lights in your Scene, because the Scene needs less Texture memory for lightmaps.

Use Shaders or Materials to simulate lighting when possible. You can use custom Materials to simulate different kinds of light effects. For example, you might want your character to have rim lighting to improve her visibility and visual look. Instead of using lights to create this effect, you can use a Shader to create the illusion of lights.

Shaders can be used to create a large variety of useful visual effects and styles. More information on Shaders and Materials can be found in a previous project of this course.

Regardless of what kind of lighting your Scene uses, it’s important to make sure your Mesh Renderer settings are correct.

A good principle is to turn off anything that you’re not going to use. Settings like Cast Shadows can add extra cost to rendering the Scene, even if the object is unlit. The following screenshot shows an example of the Mesh Renderer settings: 

The options shown in the screenshot are set to receive lighting, but not reflections, by blending the lighting information from the nearest probes. Cast Shadows is turned off because we are using the blob method. Receive Shadows is also unticked because the Scene is baked and nothing is casting a real-time shadow. 

Shadows add realism to a 3D environment, but can be costly to calculate at runtime. On mobile devices, it’s best to try to fake shadows using Shaders, Textures, or other methods that don’t rely on shadow-casting lights. In the next tutorial, we’ll take a deep dive into a lighting demo that shows off the potential performance gains of baked lights.

Shadows

1. Implementing Fake Shadows

2. Mesh Renderer Settings

3. Conclusion

Complete this tutorial