Study Journal Lei Yu

ITGM 755 - Interactive Design and Game Development

Studio I

Fall 2012

Professor Josephine Leong

Week 1(September 10 -16)

Project proposal

This week I need to find out three interesting topics for doing my thesis. Lighting and Texture are my favorite part. I

also start some Unreal game project these days. By doing Unreal project, I realized the lighting system in Unreal is

quite different with Maya. I want to go further in game engines., so I think start dig the lighting system or the lighting

methods is a good direction.

Three ideas:

1. The Unreal Engine does not calculate bounced or ambient light, and so you need to use tools to simulate these

effects. Consider my background; I have lots of experience and tricks to do good render for animation films. I think

for dig more about Unreal Engine, I might be find something that already done in animation or visual effect but not

have been done in game. A combination of the two will be a good topic.

For doing this research I need to get involve in Unreal first. So I am planning to start from the Unreal lightings, then

the way of simulation bounced or ambient light in Unreal. After doing this, I hope I can figure out some branch they

are not done in Unreal. At last I will create an environment for this project.

2. Unreal Engine is a very power tools to use, but the working process is quite different with animation films. For

learning and working with Unreal Engine, I think maybe there are many people like me, who is not familiar with

game process. Working through the process, I will get better work flow with the game process. To research and

compare with others work flow, make the summary and analysis, might be get a good work flow process.

3. Unreal generates light maps and shadow maps for all objects and lights that do not move during gameplay. It also

has dynamic shadows for moving things. I am interesting for these shadow maps and want to explore more about

these shadows in the game. These topics seem need to start with basic technique of engine.

Week 2(September 17 -23) Proposal

This week I need to start research different ways to simulate bounced or ambient light in Unreal. Like ambient

occlusion. I also need to get in to Unreal Materials. After doing research, hope I can narrow done my first topic and

get some specific points.

Check point 2

Week 3(September 24 -30)

It seems a lot of work already done in the area and they got very good effect. I got some new ideas from the

professor, such as object reflect, and sky light, bounced with the object. Also the light in different weather condition.

I will keep on dig my first ideas then from lightmass, then post process this week. Hope there’s some new things.

Then create a new simple level to experiment these techniques.

This weekend I finished a small level and start to explore the lighting system in Unreal. The light and fog is very

powerful. Just easy to place then you can get a good result. The light shows good behavior for general things.

However, when get into details it has big issue. When I add new light for center area, it seems this light also

illuminate other area. So the lighting area becomes an issue. Unreal light has the radius to control the illuminate area,

but only for the point and spot light. (Can I change the radius shapes, it will gives more control about the light)

For different lights, the functions are different. The sky light and directional light is different with spot and point light .

Sky light and directional light seems like ambient light, it will fade everything in the scene. ( Lighting scenario for use

sky light and directional to illumined both indoor and outdoor)

For doing this small levels, I think the lighting in unreal is very powerful but the controls is a little weak. There are

few light options, and the point light is the most important light in unreal. Right now each game, seem place many

point lights and use the radius to control the light area. I think there ’s better way to balance ambient light as global

illumination to lit the game not just place many point light.

Statement and Abstract

Human characters are often represent how stylized and realistic the games look. With the good materials, textures

and modeling help, the lighting plays the largest role of all. There ’s several ways to tweak things to make character a

better look.

Implementations of a Rim Lighting for characters can vary dramatically enhance the character performance in the

game.

Create an Optimization lighting scenario

Week 4(October 1-7)

This week I start to do shadow testing and different shadow map calculate method. Each light that strike a static

mesh, a separate shadow map must be generated, and the final result is to combine all this shadows. The potentially

decrease game performance by relying too heavily on this method.

The shadows from different lightings

The shadow cast by the light is only visible when the camera is within a certain distance from the object itself.

Directional light, the shadow is stored as imagine. Like trace shadows have blur edge. It seems calculate alpha

channel for the shadows.

Sky light, the default setting for cast shadows is unchecked. Compare with checked this and unchecked, the shadow

result is the same but when cast shadows checked, the scene is dark than unchecked. It seems the sky light does not

cast shadows.

Check Point 3

Week 5(October 8-14)

This week I work on my thesis statement and abstract. List below is my statement variation.

Statement

Human characters are often represent how stylized and realistic the games look. With the good materials, textures

and modeling help, the lighting plays the largest role of all. There ’s several ways to tweak things to make a better

look.

Implementations of a Rim Lighting for characters can vary dramatically enhance the character performance in the

game.

Abstract

Rim lighting is a technique most frequently used on dynamic objects and characters in order to better define the

object(s) silhouette and separate it visually from the surrounding environment. It represents the back angle lights

that typically use in a standard 3 point light setup (Key, Fill, Back-light). Create a Color Rim Lighting for characters

allows to change the character’s color values based on the reference of how light reacts to color values. Darker values

absorb the light and higher value colors bounce the light creating more rim lighting which allowed the bloom factor of the

PostProcess to be more settle.

Week 6(October 15-21)

I talk with professor about my proposal of the way to enhance the character lighting in real-time. I might have

several possibilities to do this.

1. Build a character pipeline

2. Goes to the art direction, I can use different lighting or ways to create the same effect. Discuss them and

compare them and give the result of advantage or disadvantage.

3. Build own custom light, to change the character lighting or texture properties to give the character interactive

with the different environment.

The way to do this is to write the lighting information in to shader. So this week my research will be focus on the

technique. Such as how does the lighting and texture work in Unreal? Then I will move on the shader and

texture.

Check Point 4 This weekend the professor recommends the game Team Fortress 2 to me. In this game the designer play with the

shader and built out a Non-photo realistic rendering techniques. They use material editor and use the custom

lighting channel to bake the lighting and color information on the material. It’s kind of pre-set the lighting

information in the characters. There are several potentials to dig this method. Use the blend mold to blend several

textures together. Then use a way to control which texture to show in the final render result.

Final thesis proposal

For my final thesis direction, I want play with the lighting and material in unreal. So I choose the third way to doing

my thesis. I can use the material editor and the kismet (UScript) to create a changeable texture system for the game.

It’s a dynamic shader system for the real time, such as when the player interactive with the environment, the texture

can be changed depend on the situations. (Fire, water, combat damage)

My focus is character’s cloth effect. My purpose is trying to manually setup expressions and parameters for materials

with UScript or Kistmet in real-time, outside of the materials editor. My goal is to find the possible way to create new

expressions which can define material’s values, and texture information. These expressions need to be considering

several parameters such as time, distance and the persistent character damage. When the player interacts with the

environment, these expressions will control to show which texture will be render in the final result. It has a dynamic

visual result for the player.

Week 7(October 22-28) Feedback about the visual component

Need more information to support why doing this thesis. Add more information for case research. Like in real games

the current situation for this and the ways to do deal with this. Give the proposal for my way.

Make the example simple so it easy to see the effect.

Add more variations for materials, to show different material has different result.

Thesis paper outline process

For writing my thesis paper, first I need to find out the purpose and importance for doing this thesis. Why dynamic

shader system in real game is important? The first part of my paper is to discuss the reason and meaning for doing

this paper. Firstly I need some theory or real game case with dynamic shader system in games. List the advantage of

dynamic shader system and how they enhanced the game experience.

The second part of my thesis paper will be the general research for dynamic shader system in games. This can be

separate into two parts. The first part is the types of dynamic shader in games. The second part is the way how they

make the dynamic shader system in their games. The last part of my thesis paper is my way to create dynamic

shader system. The first part is the general modes of my shader system. The second part is the detail case for how to

create my shader system. Then the third part is to discuss my shader system. (Is this workable in the real game?)

Visual Component

This week I start to do my visual component. I use a download game model to do the testing. I created two versions

of clothes. One is new the other have some dirt on the shoes and weapons. I use maya to assigned the shader

network, then made the FBX file to bring it in to UDK. Here is the look of my character.

Week 8(Oct. 29-Nov.4)

Dynamic shader system in game

Currently we have to place all the material expressions in the material editor. The texture information is preinstall in

the material editor.

The common way used in current game:

Material Instances

Using Scripted Textures (render anything to a texture using the Canvas functions, which can then be used in a

material)

Scripted textures allow arbitrary drawing to a texture during runtime from UnrealScript. This drawing is done through

the use of a Canvas and the functionality it contains. This means text, materials, other textures, etc. can all be drawn

to the scripted texture.

Visual Component

This week I use Maya created a simple cloth plane. I am play with the texture map such as normal map, specular

map, diffuse map, displacement map and transparent map in Maya. I increased the dirt level to demonstrate the

appearance different level of damage of the cloth whiles the character in game. I use the transparent map and the

displacement map to demonstrate the damage of the cloth.

Check Point 5

Week 9 (Nov5-8)

The dynamic shader in the game is not new. It is very common to see in the particle system. This week I start to

research some math mode for create dynamic materials.

Thesis variations

A changeable appearance for the character will add interesting and dynamic experience for player.

Persistent character change can be used as a narrative or gameplay in game. A character dynamic shader system

allows changing the character’s appearance during the game run.

A character dynamic shader system allows to change the character’s appearance while the player interactive with

different environment. It will add interesting and dynamic experience for player.

Outline

Introduction

An Introduction to dynamic shader system

What is the dynamic shader system in game

How does dynamic shader system enhance the game experience

What’s missing in today’s dynamic shader system, especially for the character

The importance and benefits of character dynamic shader system

My thesis goal of create a new dynamic shader system for character

The dynamic shader system in today’s game

A brief history of dynamic shader in game

The common way for doing dynamic shader in game

The problem and missing in game character by using today’s methods

The existing solutions and evaluation (a review of existing solutions about the strengths and weakness)

The design goal of my character dynamic shader system (describe how my shader system can overcome the

strengths and weakness in today’s methods)

The new character dynamic shader system

The concept of the new character dynamic shader system

Methodology

Methods

Design process (prototype, break down for built the shader system)

Final result and test ( Analysis and evaluate for the final result)

The potential of using this character dynamic shader system in game

Conclusion

Summary the character dynamic shader system and it contribution

The future plans about improving and accomplish the shader system

Visual Component

In the game the player will be interactive with different elements such as fire, water, sand, dirt. Considering

character’s clothing will have different level of damage of change. The procedure texture can be used to create the

noise for the material. For example, it can be used for bloodstain, dirt. It also can use as the transparence map to

control the materials opaque. This week I play with different materials. I photo several objects as my reference. I

want to use simple texture or procedure texture to recreate them in Maya. My goal is to use simple procedure

texture to simulate the real word material.

Procedure water noise test

Procedure Patten and color control test

Use simple noise procedure to simulate the brick. Mix the color and add the noise on the brick. Also test the patten

control for the procedure texture.

Procedure Patten and Color control test

Use different procedure textures to create two different materials in one shader. Then use the other procedure

texture to control the color and add noise. Blend those two material in one shader and use another procedure to

control the opaque.

Week 10

Final Statement, Abstract, Outline update

I. Introduction

1. An Introduction of dynamic materials and shader in game

2. What is the dynamic shader system in game

3. How does dynamic shader system enhance the game experience

4. What’s missing in today’s dynamic shader system, especially for the character

5. The importance and benefits of character dynamic shader system

6. The thesis goal for creating a new dynamic shader system for character

7. The benefit of the new shader system and how they enhance the game experience

II. The dynamic shader system in today’s game

1. A brief history of dynamic shader in game

2. The common way for doing dynamic shader in game

A. Material Instances

B. Scripted texture

3. The problem and missing in game character by using today’s methods

4. The existing solutions and evaluation (a review of existing solutions about the strengths and weakness)

5. The design goal of my character dynamic shader system (describe how my shader system can overcome

the strengths and weakness in today’s methods)

III. The new character dynamic shader system

1. The concept of the new character dynamic shader system

2. Methodology

A. Methods

B. Design goal (Using multiple textures per material and make it changeable during the play)

C. Design process

D. Prototype and Flow chart of the shader system

E. Break down for built the shader system

3. Final result and test

A. Analysis

B. Evaluate (Compare with other methods and list the advantage)

4. The potential of using this character dynamic shader system in game

IV. Conclusion

1. Summary the character dynamic shader system and it contribution

2. The drawback of this system

3. The future plans about improving and accomplish the shader system

Statement

A character dynamic shader system allows to change the character’s appearance while the player

interactive with different environment. It will add interesting and dynamic experience for player.

Abstract

The character signified by their clothing, appearance and weapons. However, when the game starts

these features is stable. Persistent character change can be used as a narrative or gameplay in game. In some games, characters gain different look as the game progresses. Other times, character

interactive with the environment or combat, these will cause the change of character health. The

characters may show visible wounds or appearance change during the game.

Currently we have to place all the material expressions in the material editor. The texture information

is preinstall in the material editor. My thesis will be working on the way to control the preinstalled

texture during playtime. The purpose is trying to manually setup expressions and parameters for

materials with UScript or Kistmet in real-time, outside of the materials editor. The goal is to find the

possible way to create new expressions which can define material’s values, and texture information.

These expressions need to be considering several parameters such as time, distance and the

persistent character damage. When the player interacts with the environment, these expressions will

control to show which texture will be render in the final result. It has a dynamic visual result for the

player.