Position-Based-Dynamics: A PBD fluid in unity running on the GPU

Position based dynamics is a method used to simulate physical phenomena like cloth, deformation, fluids, fractures, rigidness and much more. The key process in PBD is to simulate the object as a set of points and constraints. Forces are applied to the points to move them and then the constraints make sure the points wont move in a way that violates the simulation.

https://github.com/Scrawk/PBD-Fluid-in-Unity

#simulation #fluid

Terrain Scanner Effect

An interesting approach is used to achieve the scanner effect: spawn a transparent sphere with an intersection shader and scale it over time.

https://youtu.be/9DshpqhKDz0

#shadergraph #scan

Supercharge Your Game with Unity ECS: Scaling from 3 to 5000 Characters

The video is in Japanese, but it's made by the one and only Keijiro and has subnoscripts.
Shows how using [BurstCompile] and jobs improves performance in the sample by a lot.

https://www.youtube.com/watch?v=zn3m6ZFppdQ

#ecs #dots

Improvements to Unity shader files in Rider 2023.2

TL;DR: More autocompletion in Rider when working with shaders, which is always great and should help a lot, especially developers who are new to writing shaders.

https://blog.jetbrains.com/dotnet/2023/07/25/improvements-to-unity-shader-files-in-rider-2023-2/

#shader

Mechanics and tricks from Platformers applied to Endless Runners to improve experience

The author describes multiple platformer mechanics and provides code samples for them. I believe such mechanics are must have in a platformer game nowadays, and I definitely gonna implement all of them in a kinematic character controller I develop for my own roguelike game with platformer mechanics.

The list of mechanics:
- Early Fall: Player descends as soon as jump button is let go ending jump early.
- Jump Buffering: When the character is already in the air pressing jump moments before touching the ground will trigger jump as soon as they land.
- Predict Ground Collision: When the character is already in the air pressing jump and there is a platform near and below, it can jump as it is already on the ground.
- Coyote Time: Jump still triggered a few frames after running off a ledge.
- Catch Missed Jumps: If a player doesn’t quite make a jump either lift them up a few pixels or change the collision mask so their feet don’t hit the wall.

https://arielcoppes.dev/2023/04/10/platformer_techniques_in_endless_runner.html

#platformer

Platforming Tips and Tricks

As a game developer it is your job to make the character move as the player wants, NOT how the player inputs controls. Even if you think your niche is having a very hard game that only makes it more important that your controls are forgiving.

The post also contains a playable demo with these tricks implemented.

http://www.davetech.co.uk/gamedevplatformer

Repo of the demo: https://github.com/DavidStrachan/GM-Perfect-Platforming-Paragon

#platformer

kyubuns/AppIconChangerUnity: Change the app icon dynamically in Unity (iOS only)

https://github.com/kyubuns/AppIconChangerUnity

#icon #ios #native

Unity VFX Graph VS Particle System

A good comparison of these tools in case you haven't used VFX graph yet.

https://youtu.be/XSdXvhLjVEk

#particle #vfxgraph

Three tricks with Dictionary

Tricks are:
Custom key comparer,
TryGetValue,
GetValueOrDefault

These methods can help avoid custom workarounds when working with dictionaries

https://steven-giesel.com/blogPost/53090b7c-d594-4b55-b513-60bcc7b36f35

#dictionary

How to instantiate a prefab in ECS?

It's interesting how such a big post needed to describe so simple action as instantiation. And it doesn't even touch the topic of using a hybrid approach, for instance to connect entity to Animator so your instantiated object can be animated using Mecanim and triggered from ECS.

https://coffeebraingames.wordpress.com/2023/07/28/how-to-instantiate-a-prefab-in-ecs/

#dots #ecs

SHOULD YOU DO EARLY ACCESS?

Basically the EA path is high risk, and slightly higher reward. Don’t do EA because you need “feedback.”

https://howtomarketagame.com/2023/07/27/should-you-do-early-access

#marketing

8 TIPS to get MORE WISHLISTS!

1. Take part in the Steam fest
2. Make sure the game is polished
3. Provide a really good tutorial to teach players how to play the game
4. Implement analytics, especially for tutorial to track at which step users drop the game
5. Use Cloud Diagnostics (a Unity service for errors and crashes)
6. Add an in-game feedback form
7. Boost wishlists a week before the fest
8. Do livestreams during the fest

https://www.youtube.com/watch?v=-cnjCyYCxxc

#marketing

noio/games.noio.planter: The plant simulation from Cloud Gardens as a Unity package for level design.

https://github.com/noio/games.noio.planter

#vegetation

Optimize struct performances using StructLayout

I ran a simple benchmark that passes structs as an argument: one uses StructLayout.Sequential and another StructLayout.Auto.
I intentionally ordered fields in a way that makes them have padding.

And result is (the formatting in mobile clients sucks):
| Method | Mean | Ratio |
|------- |---------:|------:|
| Auto | 298.6 us | 1.00 |
| Seq | 359.0 us | 1.20 |

Obviously copying struct that is bigger due to the padding to pass it as an arg is slower. But this operation is so quick that it might be a problem only on a very hot path.
It can be avoided by using 'ref' parameter so no copying occurs. I've also thrown readonly structs to the test.
| Method | Mean | Ratio |
|------------- |---------:|------:|
| Auto | 318.5 us | 1.00 |
| Seq | 398.7 us | 1.25 |
| AutoRef | 254.5 us | 0.80 |
| SeqRef | 299.7 us | 0.94 |
| AutoReadonly | 312.9 us | 0.98 |
| SeqReadonly | 390.5 us | 1.22 |

As you can see passing both structs by ref is definitely faster. But Auto is again faster than Sequential. While readonly structs don't have any performance benefits according to this benchmark. To make sure a defensive copy of a readonly struct is avoided, I've also added 'in' parameter to the arg and now we can see that structs are not copied anymore and performance is on par with the 'ref' parameter
| Method | Mean | Ratio |
|--------------- |---------:|------:|
| Auto | 299.9 us | 1.00 |
| Seq | 369.1 us | 1.23 |
| AutoRef | 245.1 us | 0.82 |
| SeqRef | 305.7 us | 1.02 |
| AutoReadonly | 309.1 us | 1.03 |
| SeqReadonly | 369.6 us | 1.23 |
| AutoReadonlyIn | 255.4 us | 0.86 |
| SeqReadonlyIn | 303.4 us | 1.02 |

I performed all these benchmarks in .NET. It would be very interesting to look at it in Unity using IL2CPP, whether it affects performance in C++ or not.

https://www.meziantou.net/optimize-struct-performances-using-structlayout.htm

#optimization #struct #layout #ref

Designing a Realtime Combat System. This article is about melee combat foremost.

A great list of combat mechanics, how and when each of them should be used or not. Must help a lot when designing combat in your game.

https://howtomakeanrpg.com/a/designing-a-realtime-combat-system.html

#combat #platformer

Speed up the build process of your Unity projects

It's a great post with practical steps based on real experience. I can confirm that these steps are helpful, as I had been working on the same project when these approaches were introduced.
It would be also interesting to read more about splitting the code base into multiple projects and how to properly handle the build process in that case as no references were provided in the post.

https://medium.com/@wondrous_aqua_toad_341/speed-up-the-build-process-of-your-unity-projects-a4e3f048c32f

#build

Dependency injection

The author clearly shows how dependency injection helps make code more maintainable and testable.

https://youtu.be/J1f5b4vcxCQ

#pattern #di

Developing SWIFT, Part 1: Combat & Gameplay Mechanics

The breakdown of combat and gameplay design decisions in a competitive melee combat action game

https://80.lv/articles/developing-swift-part-1-combat-gameplay-mechanics/

#gamedesign #combat

Use string.Equals with StringComparison.OrdinalIgnoreCase parameter instead of manually adding ToLower()/ToUpper() for better performance and cleaner code.

#string #performance

Custom SRP 1.0.0

How to upgrade the old SRP tutorial to Unity 2022. Some of these fixes I had to do myself when I followed this series a long time ago but using Unity 2021. It's great that Jasper supports the series and shared the update.
I personally recommend this series as it not only shows steps how to implement your own rendering pipeline, but gives an idea how some parts of rendering work in general.

https://catlikecoding.com/unity/custom-srp/1-0-0/

#srp

Mesh-Peeling

https://github.com/bunszr/Mesh-Peeling

#mesh #peel