Title 44pt Title Case Advanced Rendering Techniques Used ......Intended to share the experience of learning Unity from scratch Available for free at MaliDeveloper.arm.com V1.0: Optimizing

Title 44pt Title Case

Affiliations 24pt sentence case

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Advanced Rendering Techniques Used in the Ice Cave

Sylwester Bala

GDC 2016

Staff Software Engineer, ARM

© ARM2016 2


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Agenda

About Ice Cave project (video)

Composition overview of a single frame

Optimized techniques

Q&A

Ice Cave

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What’s in the Ice Cave?

Triple Level Reflections Plane Reflections

Local Environment Reflections

Global Reflections

Dual Level Refractions Local Environment Refraction

Global Environment

Dual Level Shadows Local Cubemap Shadows

ShadowMap For Dynamic Objects

Procedural Skybox

Uniform Mist

Particles Mist

Fireflies With Trails

Dirty Lens Effect

Glowing Zodiacs

Bloom/Glare

Frost

Crystals

Enlighten

Light Shafts

Ice Parallax Effect

Dripping Water

Fresnel + Light Diffraction

Snow Leopard Ghost + Glow

Glints

Subsurface Scattering

GUI

How is This Frame put Together?

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Generate Shadowmap Pass

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Planar Reflections Pass (Dynamic Objects Only)

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Clear Framebuffer

Color Depth

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Plinths

Color Depth

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Platform

Color Depth

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Phoenix

Color Depth

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Zodiac Animals

Color Depth

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Phoenix Base

Color Depth

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Cave – Depth Only

Color Depth

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Cave

Color Depth

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Crystals

Color Depth

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Water Drops

Color Depth

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Procedural Skybox (Last Opaque Object)

Color Depth

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Fireflies

Color Depth

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Bloom

Color Depth

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Glints

Color Depth

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Particles Mist

Color Depth

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Dirty Lens Effect

Color Depth

Optimized Techniques

Skybox, Cave, Phoenix & Crystals,

Platform, Bloom, Light shafts, Particles

mist, Dirty lens effect, Glints.

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Procedural Skybox

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Skybox DIY

Blend two cubemaps at a time

according to the sun position

LERP

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Skybox DIY

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Skybox DIY Given the sun position in world space, we check if the fragment is “inside” the sun area by checking the dot

product of the view vector against the sun direction.

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Cave

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Cave – Depth Pass

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Cave – Only Render What’s Visible!

World space normal map.

2-3 cycles faster

(6% perf. uplift for the Cave)

Diffuse texture map

Environment map for reflections

Local cubemap shadows

Procedural skybox

Global illumination

Icy parallax effect

Procedural mist

Shadowmap for dynamic objects

Animated projective textures

We’ve managed to combine all these effects in one

shader and still maintain high performance.

Phoenix

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Phoenix & Crystals in One Shader & One Pass

Reflection & refraction pre-baked environment

Mipmaps are also pre-generated!

Procedural skybox

Normalmap used for lighting, specular, reflections and

refractions

Diffuse color

Roughness map - this is what makes the Phoenix look icy!

Determines mipmap level of the pre-baked environment

Global illumination

Platform

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Platform

Tangent space normal map

Diffuse texture map

Environment map for reflections

Local cubemap shadows

Procedural skybox

Global illumination

Procedural mist

Shadowmap for dynamic objects

Planar reflections

Light Shafts

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Light Shafts

Upper cross section is fixed

Adjustable cone angle

Light shaft orientation follows the light

Maximum angle to follow the light

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Light Shafts

Behaviour

Fading at cone borders to avoid sharp edges.

Fades when the camera gets closer (Min & Max

distance).

Texture

Animated texture coordinates for RGB

Still Alpha channel mask to fade the

light shaft top-bottom

Tiny shader

Very simple fragment shader

Additive alpha blending (Blend One One)

Culling Off

ZWrite Off

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Bloom

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Bloom Effect Based on Sprite

Behaviour

Fades when the camera moves closer (Min & Max distance)

More intense when the camera moves away

Can rotate in any axis. It is oriented to camera in the free

axes

Coupled with the light source. Bloom intensity depends upon

light to sprite.

Final intensity combined with different intensity maps.

Textures

Texture rotates depending on camera position to add a

parallax like effect

Minimalistic shader

Very simple fragment shader


Culling Off

ZWrite Off

N * L

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Bloom at the Entrance to the Cave

Sunset Daylight

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Dirty Lens Effect

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Dirty Lens Effect

Full screen quad

mesh.vertices = new Vector3[] {

new Vector3(-1, -1, 0), new Vector3(1, -1, 0), new Vector3(1, 1, 0),

new Vector3(-1, 1, 0)};

mesh.uv = new Vector2[] {

new Vector2(0, 0), new Vector2(1, 0), new Vector2(1, 1),

new Vector2(0, 1)};

Intensity depends on sun and camera vector alignment + bloom

vec plane alignment.

Minimalistic shader

Very simple fragment and vertex shaders


Culling Off

ZWrite Off

ZTest Always

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Particles Mist

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Particles Mist

Render a few big particles with different

orientation and rotation

Not too many as you want to keep the

overdraw factor low

Fade a single particle in and out

according to the camera view vector

Apply additive blending

Finally apply a mist texture

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Particles Mist

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Glints

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Glints

Remove vertices from the original mesh and leave minimum number

The reduced cave contains 200 vertices

For each vertex spawn a particle

Assign a glint texture:

Use local cubemap shadow to fade the particle in and out

© ARM2016 50




Glints – Final Result

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First released at Unite Seattle 2014

Intended to share the experience of learning Unity from scratch

Available for free at MaliDeveloper.arm.com

V1.0:

Optimizing Applications and quality settings in Unity (Chapter 2)

Profiling Applications with the Unity Profiler(Chapter 3)

Optimizations: Application, GPU and Assets (Chapter 4)

V2.0:

Enlighten (Chapter 5) and advanced graphics techniques (Chapter 6)

V3.0:

More advanced graphics techniques (Chapter 6)

ARM Guide For Unity Developers: Optimizing Mobile Gaming

Graphics

Download the ARM Guide for Unity Developers

at MaliDeveloper.arm.com

http://malideveloper.arm.com/

Optimizations Wrap Up

© ARM2016 53




ALU (Arthmetic Logic Unit)

Vectorise

Use appropriate precision of

variables

Use standard functions – do

not reinvent the wheel

Move calculations to vertex

if fragment bound

Transform normal map to

world space

LS

(Load Store)

Keep number of uniforms

and varying in the physical

registers

Select the right precision –

the lower the better

performance, but check it is

not causing artifacts

Using too many or high

precision will trigger loading

and storing data from / to

main memory

Texture

Use Mipmaps

Compress

We didn’t hit the limit of

textures in the Ice Cave

demo.

Mali is very good at handling

multiple textures

Bilinear – 1 cycle

Trilinear – 2 cycles

Optimized cubemap fetch

GPU Tri-Pipe Optimization Hints

Use Mali Offline Shader compiler to find out more about your shaders and bottlenecks!

The trademarks featured in this presentation are registered and/or unregistered trademarks of ARM Limited (or its

subsidiaries) in the EU and/or elsewhere. All rights reserved. All other marks featured may be trademarks of their

respective owners.

Copyright © 2016 ARM Limited

Thank you!

Confidential © ARM 2016 55

Text 54pt Sentence Case

ARM Booth #1624 on Expo Floor: Live demos of the techniques shown in this session

In-depth Q&A with ARM engineers

More tech talks at the ARM Lecture Theatre

http://malideveloper.arm.com/gdc2016: Revisit this talk in PDF and video format post GDC

Download the tools and resources

To Find Out More….

© ARM2016 56




Vulkan on Mobile with Unreal Engine 4 Case Study Weds. 9:30am, West Hall 3022

Making Light Work of Dynamic Large Worlds Weds. 2pm, West Hall 2000

Achieving High Quality Mobile VR Games Thurs. 10am, West Hall 3022

Optimize Your Mobile Games With Practical Case Studies Thurs. 11:30am, West Hall 2404

An End-to-End Approach to Physically Based Rendering Fri. 10am, West Hall 2020

More Talks From ARM at GDC 2016 Available post-show at the Mali Developer Center: malideveloper.arm.com/

Documents

Title 44pt Title Case Advanced Rendering Techniques Used ......Intended to share the experience of learning Unity from scratch Available for free at MaliDeveloper.arm.com V1.0: Optimizing