Unity

I wanted to delve further into using Event systems in Unity specifically when building UI systems, so I collected a few resources I thought would help with researching that. These tutorials cover everything from the basic foundations of Events themselves to fully fledged UI system tutorials near the end implementing those tools and concepts covered in the earlier tutorials.

I think Event heavy systems are very effective ways to build out UI in games, so I want to get a better grasp of setting that up. I especially think the final tutorial by Jason Weimann will help bring those topics together as well as cover other important factors for building larger scale UI systems.

via Blogger http://stevelilleyschool.blogspot.com/2021/09/unity-using-events-and-building.html

Unity Shader Graph – Energy Shader – by Casey Farina

digm520admin / August 9, 2021 / ShaderGraph, Shaders, Tutorial, Unity

August 9, 2021

Shader Graph

Title:
ART 200: Creating an energy Shader in Shader Graph in Unity

By:
Casey Farina

Youtube – Tutorial

Description:
Tutorial on creating an energy effect on a surface with Unity’s Shader Graph.

Introduction

This tutorial covers the creation of a shader in Unity’s Shader Graph which covers the surface of an object with a glowy, plasma-like effect. Further in the tutorial they cover how to make the less pronounced parts of the effect actually completely transparent, which gives a cool effect on its own, or allows for this to be placed over other effects or surfaces to apply the effect with gaps showing the surface below.

Fig. 1: My Results of the Energy Shader Along with Shader Graph View

Quick Notes

HDR Color and Emission

It starts with HDR color with significant intensity into Emission to create glowing, radiant effective.

Voronoi Noise in Layers

Use Voronoi noise to create moving globules effect within the energy. Contrast node used with this to create more distinct dots.

They then created two Voronoi noises with differet cell densities and blended them with a Blend node, giving a combination of tiny particles moving with some larger effects moving throughout the material.

Transparency and Alpha Clip Threshold

By making the Surface of the Graph Inspector Transparent, feeding the Blend result into the now present Alpha on the Fragment node, and setting a proper Alpha Clip Threshold (0.1 is usually a good start), then you can get an effect where parts of the energy shader are totally transparent and see through.

Summary

This tutorial helped me make a simple, yet effective energy effect shader that works decently well on multiple surfaces. The extra segment on including transparency into the effect really took it up a level for me as an interesting effect that could have a lot of uses. This would help expand the effect a bit by also giving it the option of being used on a larger mesh outside of an object’s actual mesh to provide a sort of aura off of and around an object that could be cool, as well as allowing for layering with other effects easier.

They also covered a small segment on using the Gradient node for some strange effects. This was a small segment that also didn’t appeal to me particularly so I didn’t try that portion out myself. That could give some more variety to the tool, but it just wasn’t something I wanted currently.

My result can be seen in action below with a few variations in speed of the effect and color!

via Blogger http://stevelilleyschool.blogspot.com/2021/08/unity-shader-graph-energy-shader-by.html

Unity Shader Graph – Signed Distance Fields – Update with Subgraph Fix

digm520admin / June 25, 2021 / Math, Math for Game Programmers, ShaderGraph, Shaders, Tutorial, Unity

June 24, 2021

Shader Graph

Unity

Title:
Drawing Boxes and Rectangles in URP Shader Graph with 2D SDFs! 2021.1 | Unity Game Dev Tutorial

By:
Ned Makes Games

Youtube – Tutorial

Description:
Exploration into calculating signed distance fields and using them with Unity’s Shader Graph.

Title:
Rectangle SDFs and Procedural Bricks! Video Production Stream | Unity Game Dev Livestream

By:
Ned Makes Games 2

Youtube – Tutorial

Description:
The full stream which most of the previous tutorial is pulled from. Useful for any more in depth questions of previous tutorial.

Overview

When I visited this tutorial yesterday I ran into an issue with Unity 2021.1.3 that working with subgraphs was extremely bugged and error prone. I had seen online that later versions potentially fixed the issue, so I download the latest version, 2021.1.12, and this did indeed fix the issue for me, making this tutorial much easier to follow along with.

This tutorial was mostly just looking at the subgraphs and shader graphs they built and following along to build them out myself. This was at least a decent learning experience at getting familiar with the work flow of setting up subgraphs for your shader graphs, as well as just using a lot of the math nodes.

Helper Scripts to Show Off Shader

Along with building the shader, they made two simple scripts to make the shader a bit interactive and more flexible.

SetPoints

This class was responsible for letting the user move the two points dictating the general length of the rectangle shape by just clicking and dragging. This however did not work immediately, as they were using a helper class named MousePointer I did not use.

I was able to get a similar result by replacing their process of getting the point:

var p = MousePointer.GetWorldPosition(Camera.main);

with my replacement:

var p = Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, distanceToPlane));

distanceToPlane was a value the user could put in that is the distance from the camera to the flat plane the camera is facing to test the shader. As long as the exact same distance is put there for the z-value of ScreenToWorldPoint, the points moving correlate exactly with where the user is dragging them.

RectangleThicknessByScrollWheel

This class lets the user control the thickness, or width, of the rectangle with the scroll wheel. This class directly worked as shown.

General Notes with Scripts Interacting with ShaderGraph Properties

Integrating the scripts with the Shader Graph properties was actually pretty easy. It worked similarly to working with the Animator in Unity. You just use methods like SetFloat() and give it two parameters where one is the exact string name of the property you want to set, and the second is the value you are passing in to said property. It is worth noting this was just accessed through the Material, there was no strange Shader Graph object that needed to exist or anything like that.

An example of my implementation of the tutorial can be seen below.

Unity Shader Graph: SDF Rainbow Pulse from Tutorial by NedMakesGames from Steve Lilley on Vimeo.

Video Example of my Following of the Pulse Shader in the Ned Makes Games Tutorial

via Blogger http://stevelilleyschool.blogspot.com/2021/06/unity-shader-graph-signed-distance_24.html

Unity Shader Graph – Signed Distance Fields and Subgraph Errors

digm520admin / June 24, 2021 / Math, Math for Game Programmers, ShaderGraph, Shaders, Tutorial, Unity

June 23, 2021

Shader Graph

Unity

Title:
Drawing Boxes and Rectangles in URP Shader Graph with 2D SDFs! 2021.1 | Unity Game Dev Tutorial

By:
Ned Makes Games

Youtube – Tutorial

Description:
Exploration into calculating signed distance fields and using them with Unity’s Shader Graph.

Overview

This shader tutorial quickly explores calculating signed distance fields and using that for interesting effects. These effects were built in HLSL in the tutorial video originally, but they also show how these can be implemented with Unity’s Shader Graph system. I wanted to use the Shader Graph approach, but unfortunately I found that Unity’s Shader Graph Subgraphs have some major issues.

Signed Distance Fields (SDFs)

Signed Distance Fields (SDFs): calculate the distance from any arbitrary point to a specific shape

Principles of Calculating

To start, they look at an example using a rectangle whose center is at the origin (0, 0).

First, they find the distance from the point, p, to the center of the rectangle, which is just the length of the Vector2 p because the center is at the origin.

Then, using the symmetry of the rectangle, the absolute value of point, p, and the half dimensions of the rectangle are used to determine the distance of the point to any corner of the rectangle.

To get the positive results, they find the vector between the absolute value of point, p, and the corner of the rectangle and find the length of this vector after converting any negative components to 0.

Since the core of an SDF is that it is signed, meaning that a point inside the shape returns a negative value and a point outside the shape returns a positive value, they expand it to deal with negative distances. The vector, d, which is that from the absolute value of point, p, to the corner of the rectangle is only inside of the shape when both components of d are negative.

Assuming both components of d are negative, the result from the previous step already results in 0, so they can add a secondary component to this that returns a negative result in this case. By using min(max(d.x, d.y), 0) they can find this distance because a point within the rectangle must be closer to one wall or the other, or they are identical values. This is why there also is no rounded effect within the rectangle.

Moving the rectangle’s center from the origin just requires an additional offset argument.

Then, rotation requires another argument, and requires rotational matrix math (something I covered in my investigation to changing vector spaces).

Unity Problem with Subgraphs

While following along to mimic their Shader Graphs, I came across a Unity issue working in Sub Graphs especially. When creating properties and moving those property nodes around, Unity consistently runs in ArgumentNullException errors which completely shut the graph down and prevent any further progress until it is closed and reopened. Apparently Unity versions 2021.2 and up may work better with this, so I will have to look into more Unity versions in the future.

via Blogger http://stevelilleyschool.blogspot.com/2021/06/unity-shader-graph-signed-distance.html

Unity Shader Graph – Liquid Effect by Gabriel Aguiar Prod.

digm520admin / June 18, 2021 / ShaderGraph, Shaders, Tutorial, Unity

June 18, 2021

Shader Graph

Unity

Title:
Unity Shader Graph – Liquid Effect Tutorial

By:
Gabriel Aguiar Prod.

Youtube – Tutorial

Description:
Quick shader graph tutorial exploring interesting effects of moving shader based on psuedo-physics.

Overview

This shader tutorial looked like a great way to extend my knowledge on Unity’s shader graph since it appears to have some neat and unique mechanics. The fact that the shader is responding to the changes in position and rotation of the object explore ways to have shaders follow physics-like rules to create effects visually that can mimic for physical phenomena. Many of this user’s tutorials also include setting up the initial models, but I think this effect can work decently with other simple shapes I can easily make with ProBuilder.

via Blogger http://stevelilleyschool.blogspot.com/2021/06/unity-shader-graph-liquid-effect-by.html

Game Project: Flying Game: Sonic Boost – Part 4 – Projectile and Environment Interaction

digm520admin / June 2, 2021 / Environment, Game Feel, GameDesign, GameJam, GameMechanic, Unity

June 2, 2021

Flying Game

Projectile

Overview

I was trying to think of ideas on how to add an extra mechanic to the flying controller that ties in with a fast and agile moving controller, and thought of tying in some type of sonic boom effect. With this, I thought creating an expanding projectile from the player after boosting could be an interesting way to generate these projectiles. I then explored a few ways to have the projectile interact with the environment and came across a relatively simple one that provides some fun feedback.

Sonic Boom Projectile

Everything about the projectile is rather simple. The projectile is generated when the player performs a fully charged boost. It then expands at some growth rate (dictated by the projectile controller on the player) up until some maximum size (dictated in the same location). As it encounters objects with an IDestructible interface, it will cause them to perform their Destroyed() method.

This gives a pretty cool effect that at least has a minimal basis in real world physics. It also makes tight turns and effective direction changes tied to a boost more satisfying when performed properly. It does have a major flaw currently however in that a majority of the action is normally happening behind the player, so they do not get to witness it most of the time. This is a pretty severe drawback that I will need to investigate some solutions to.

Voxelized Environment Obstacles

I initially liked the idea of creating targets or obstacles that could be destroyed by this growing sonic boom that would deteriorate as the sonic boom moved into it, as opposed to a more general game approach where contact would just do damage and destroys the entire object as a whole. This led me to making a bit more voxelized targets, which were made up of several chunks instead of just being a single large mesh.

To begin, I created a Voxel Obstacle script which is the overall container of a full obstacle made of several voxelized elements. This script just holds 3 dimensional values and builds out a solid cube/rectangular solid based on those dimensions.

The elements that make up the full obstacles are just simple prefab cubes for now, with a VoxelObstacleElement script. That script implements the IDestructible interface just so they have a Destroyed() method for the projectile to interact with.

Initially I had these elements have their gameobjects destroyed on impact with the projectile just to test the interactions. This was an ok approach, and gave the deteriorating effect I wanted that was at least more fun than the whole area exploding immdeiately on impact. However, I explored a more physics-based approach that looked a lot more satisfying. I simply turned the elements’ rigid body component from kinematic to non-kinematic to effectively enabled their physics. This gave a fun tumbling and physics-y effect for the individual blocks as they interacted with the projectile.

This is a decent spot for most of the elements of this small game project, and I think the next step is just building out a better level to test the individual mechanics in. I would also like to add a bit more to the projectile/environment interaction just to make it a bit more impactful. I would also like to remove the strange interaction of hitting the blocks from above, as without any additional force, they don’t really move since they really start by moving downward with gravity being the only force acting on them.

Sonic Boost – Projectile Tests and Environment Voxel Interactions from Steve Lilley on Vimeo.

Video: Sonic Boom Projectile and Obstacle Destruction Showcase (1st and 2nd Iteration)

via Blogger http://stevelilleyschool.blogspot.com/2021/06/game-project-flying-game-sonic-boost.html

Accessing Variables in Other Scripts in Unity

digm520admin / May 26, 2021 / Programming, ProgrammingArchitecture, Tutorial, Unity

May 26, 2021

Accessing Variables

Unity

Title:
How To Access Variables From Another Script In Unity

By:
Infallible Code

Youtube – Tutorial #1

Description:
Goes over many programming techniques within Unity to access variables in one script from another.

Key Concepts

Scripts

C# classes that inherit from MonoBehaviour.

Collaborators

Scripts that require a reference to at least one other script in order to function.

Dependencies

Objects that collaborators need in order to function.

Categories of Resolution

Where the burden of dependency resolution lies.

External Resolution

The responsibility of dependency resolution falls somewhere else.

Public Properties

Expose dependency of a public field or property

Simple and requires no overhead, but can easily make bugs that are also hard to debug. This is because it can be unclear where the dependencies lie.

Editor Properties

Expose serializable dependencies in the Unity editor.
Use SerializeField on attribute private properties.

Similar to public properties, but are much safer.

Unity Event Methods

Functions that are called when specific events occur at runtime.

This specific example covers methods like OnCollisionEnter(). These are functions that are called when specific events occur, and they help resolve dependencies when those events are triggered.

Internal Resolution

The script itself is responsible for resolving its own dependencies.

FindObjectByType() Method

Search for dependencies in the scene based on their type.
FindObjectsByType() returns a list of matching objects.

This can be tricky to use sometimes since you may not be sure of the state of your scene when this is called. It is also relatively expensive. Most consistent to use to find manager scripts, since they should confidently be active in the scene when called.

Static Instances

Expose dependency on a public static property.
Commonly used in the Singleton pattern.

Dependency Injections

A pattern for automating dependency resolution based on a configuration.

It allows you to configure all your dependencies in one place and have them resolve automatically based on that configuration.

Summary

I have used all these techniques before, but it is always good to find condensed lists of them all together to really help organize them. Determining the cleanest and safest way to pass around variables through scripts is something I work on a lot, so laying out these options to go through in an effort to determine the best approach is always helpful. This also led me to some other resources on the topic that I am looking forward to investigating.

via Blogger http://stevelilleyschool.blogspot.com/2021/05/accessing-variables-in-other-scripts-in.html

Singletons in Unity and Many of Their Downfalls by Infallible Code

digm520admin / May 26, 2021 / Programming, ProgrammingArchitecture, Tutorial, Unity

May 26, 2021

Singletons

Unity

Title:
Everything You Need to Know About Singletons in Unity

By:
Infallible Code

Youtube – Tutorial #1

Description:
Goes over the true properties of singletons in code and why they should be used sparingly in Unity game development.

Intro to Singletons

Singleton Pattern: class that is both globally accessible and can only be instantiated once

Common Example:

Audio Manager – because it is something many scripts will want access to, and you specifically want only one in your game at a time

Singleton Requirement #1: Global Access Specification

Singletons sound promising because they are an easy solution to “how do you access other scripts” or “how do you fill your class dependencies”. Using Singletons for access can hide the fact that a class depends on another, which can lead to difficult to track bugs and difficulties. This may lead to using the singleton even more than necessary because of ease of access, which creates more and more hidden dependencies.

Example #1

Non-Singleton Version

public class GameManager : MonoBehaviour
{
	[SerializeField] private Player player;
	
	privat void OnPlayerDied()
	{
		print($"Final Score: {player.Score}");
	}
}

Singleton Version

public class GameManager : MonoBehaviour
{
	privat void OnPlayerDied()
	{
		print($"Final Score: {Player.Instance.Score}");
	}
}

Because the Singleton pattern accesses a specific class directly, additions of derived classes will require more updates that may also be hard to find because of the hidden dependencies. Again, doing something similar to the Non-Singleton version of Example #1 makes it so that an additionally created derived class could fill the Player dependency with little to no edits.

Singleton Requirement #2: Restricted to a Single Instance

This is generally accomplised by creating a private constructor for the class, and then instantiating a single instance from the getter. This is already difficult in Unity as many classes you create in Unity will be MonoBehaviours, which cannot be instantiated in code with the new keyword. This is because Unity hides their constructor and allows anything to instantiate them through object.Instantiate().

So to help satisfy this, you need an extra check if another instance of the class already exists in the scene in case it was added directly in the Editor or through other object.Instantiate() calls. Once these are located, they may also require being destroyed to make sure there only exists one instance at any given time. This can also lead to strange results, as sometimes destruction prevention is used in Unity, such as with the DontDestroyOnLoad() method. Sometimes you may also get rid of and keep the “wrong” singleton if multiple somehow run into each other.

Singleton Criteria:

1) Absolutely required to exist only once
2) Must be accessible from every part of your code
3) Controls concurrent access to a resource

Summary

While I already knew that singletons should be used sparingly, having a better understanding of them fundamentally really helps put that into perspective just how sparingly they should be used. It also helps confirm that it can generally be a bad way of passing around data in Unity, and with a need that comes up so often and has so many options to be accomplished, it is good to generally remove an option from that list. It is also important to acknnowledge that in Unity specifically they are extra difficult to implement when it involves MonoBehaviours, as this again helps narrow down the process of passing around data.

via Blogger http://stevelilleyschool.blogspot.com/2021/05/singletons-in-unity-and-many-of-their.html

Game Project: Flying Game – Part 3 – Camera Controller and Zoom Control

digm520admin / May 25, 2021 / Camera, Game Jam, Programming, Unity

May 25, 2021

Flying Game

Camera Controller

Overview

After getting the basics of the camera controller down, I wanted to explore ways to make it feel more immersive. One of the ways I’ve seen racing or other fast moving games handle this was to have a zoom that mimicked the acceleration to make that feel all the more impactful. Following this, I wanted to look into connecting the player’s speed with the amount the camera zooms in on the player.

Setting the Camera Zoom Suggested by Player Speed

Since the game has a speed boost option, I wanted the impact of the speed boost to be larger than any normal speed the player can reach. With this in mind, I was looking at an approach where normally their max speed gets the camera up to around 80% of the maximum zoom, and activating a boost is the only way to hit the 100% zoom mark (creating a significant difference in zoom specifically when boosting).

One immediate issue with this approach is that any zoom that is directly tied to player speed has a jarring jump in zoom position when the player boosts, since in a single frame it jumps from rather low zoom (because charing boost goes with slowing down) to maximum zoom. So while this was a decent initial approach, I knew I would want a smoother transition system to especially deal with this common extreme case.

The approach I thought of was that the camera zoom system would read the player’s speed and suggest a position for the camera to move to. If that new position is substantially far away from the current position, it would only move a portion of the way there instead of directly there. This would help me spread out extremely large zoom changes over several frames, similar to how a Lerp function may handle this.

This ended up working rather well, and can be seen in action in the video I have linked. Another hopeful benefit of this system was that I was hoping I could remove the small zoom jitter when the player’s speed is not changing any appreciable amount. This is an effect that happens often when the player is consistently maintaing the normal top speed. I was hoping to use the opposite distance check of not changing the zoom at all at very small distance changes, but as can be seen in the video as well this does not particularly fix it currently.

Camera Controller – Zoom Focus from Steve Lilley on Vimeo.

Video: Zoom Based on Speed System for Camera Controller

via Blogger http://stevelilleyschool.blogspot.com/2021/05/game-project-flying-game-part-3-camera.html

Coroutine Fundamentals in Unity

digm520admin / May 20, 2021 / Programming, ProgrammingArchitecture, Tutorial, TutorialList, Unity

May 20, 2021

Coroutines

Unity

Title:
Introduction to Game Development (E21: coroutines)

By:
Sebastian Lague

Youtube – Tutorial #1

Description:
Covers the basics of coroutines in Unity.

Title:
Coroutines In Unity – What Are Coroutines And How To Use Them – Coroutines Unity Tutorial

By:
Awesome Tuts

Youtube – Tutorial #2

Description:
Covers some intermediate complexity uses of coroutines as well as tying them in with Invoke calls.

Title:
Coroutines – Unity Official Tutorials

By:
Unity

Youtube – Tutorial #3

Description:
Old official Unity tutorial on the fundamentals of coroutines in their system.

Overview

Coroutines appear to be a strong tool within Unity that I still am looking for ways to implement better in my systems. While understanding the basic uses for them with timing related events, I feel like they offer a lot more that I am not utilizing, so I wanted to further my understanding of them by following up on one of my older tutorial blogs and going through the tutorials it offers.

Tutorial #1 Notes

Coroutines are part of the Unity engine, and are not native to C#. They also belong to the Monobehaviour base class, so they class they are used in must inherit from Monobehaviour.

The coroutine return type is IEnumerator. Because of this, coroutines can also be stored in IEnumerator variables. This also allows them to be passed in as a paramter for the yield return statement within a Coroutine.

Use a reference to properly control the starting and stopping of a specific coroutine instance.

Tutorial #2 Notes

You can call a Coroutine from within itself (the same Coroutine). This is one way to cycle a Coroutine continously.

WaitForSecondsRealtime is similar to WaitForSeconds, except that WaitForSecondsRealtime is independent of Unity’s timescale. WaitForSeconds however is affected by the timescale. WaitUntil suspends the coroutine until the given delegate returns true.

Invoke Notes

Invoke – call a method after a given amount of time
InvokeRepeating – call a method every given amount of time, after a starting given time
CancleInvoke – stops an InvokeRepeating call

Tutorial #3 Notes

Coroutines are functions which execute in intervals. They work with special yield statements which return the code execution out of the function. Then, when the function continues, execution begins from where it left off.

Combining coroutines with properties can allow for efficient code which produces execution only when a value is changed, without the need to check for variable changes every frame with the Update() method or something similar.

Coroutine Return Statements

A substantial part of using and controlling coroutines is the various return statements you can use within them to determine when they should run and when they should pause execution. As such I listed several of these options and how they work within the coroutines.

yield return null

waits a frame before progressing to the next step

seems similar to the rate of the Update() method

yield return new WaitForSeconds(float time)

waits the given amount of seconds between each run of the process

yield return WaitForSecondsRealtime(float time)

waits the given amount of seconds, regardless of Unity’s timescale

yield return StartCoroutine(DoSomething())

waits until the given Coroutine “DoSomething” is finished running

yield return new WaitUntil(bool test)

suspends coroutine until the given parameter is true (opposite of WaitWhile)

yield return new WaitWhile(bool test)

suspends coroutine until the given paramter is false (opposite of WaitUntil)

Summary

Coroutines are starting to become a bit more clear to me, and this helped me learn a few more ways to incorporate them into my projects. Just seeing that they are specifically a Unity native concept was helpful to me as I did not think about that before, and that makes their somewhat strange nature make more sense in my head. This made it more clear that Unity is doing a lot of work behind the scenes to accomplish their main goals of determining when to start, pause, resume execution based on their yield values. Also the Unity note on tying them in with properties is very interesting and something I want to experiment with more myself for more efficient code.

via Blogger http://stevelilleyschool.blogspot.com/2021/05/coroutine-fundamentals-in-unity.html