Jesse Stiller AquaGeneral

Realtime Fluid Simulation: Projection

The core of most real-time fluid simulators, like the one in EmberGen, are based on the "Stable Fluids" algorithm by Jos Stam, which to my knowledge was first presented at SIGGRAPH '99. This is a post about one part of this algorithm that's often underestimated: Projection

MG4_F32.mp4

Stable Fluids

The Stable Fluids algorithm solves a subset of the famous "Navier Stokes equations", which describe how fluids interact and move. In particular, it typically solves what's called the "incompressible Euler equations", where viscous forces are often ignored.

Computational Fluid Dynamics (in graphics mostly)

Disclaimer: I have no professional education in Compulational Fluid Dynamics, these are various notes on what I found/learned when trying to learn a bit on the topic. Some of the notes lack sources as I wrote them up later often just remembering some StackExchange answer. Some things I might have misinterpreted.

Computational Fluid Dynamics (in graphics mostly)
General / Overview
- Overarching resources
General Concepts & Keywords

GPU Optimization for GameDev

Graphics Pipeline / GPU Architecture Overview

2011 - A trip through the Graphics Pipeline 2011
2013 - Performance Optimization Guidelines and the GPU Architecture behind them
2015 - Life of a triangle - NVIDIA's logical pipeline
2015 - Render Hell 2.0
2016 - How bad are small triangles on GPU and why?
2017 - GPU Performance for Game Artists
2019 - Understanding the anatomy of GPUs using Pokémon

About Me

高橋啓治郎 - 1977年生まれ

コンシューマーゲーム業界にて10年間の開発経験を持つゲームプログラマーです。ゲームプログラミング全般に経験を持ち、中でもグラフィックスプログラミング、AIプログラミングを得意としています。

現在は iPhone/iPad アプリの開発を主軸に置きつつ、技術書への寄稿や、ゲーム開発のコンサルティングなどを手がけています。

	// When creating shaders for Universal Render Pipeline you can you the ShaderGraph which is super AWESOME!
	// However, if you want to author shaders in shading language you can use this teamplate as a base.
	// Please note, this shader does not necessarily match perfomance of the built-in URP Lit shader.
	// This shader works with URP 7.1.x and above
	Shader "Universal Render Pipeline/Custom/Physically Based Example"
	{
	Properties
	{
	// Specular vs Metallic workflow
	[HideInInspector] _WorkflowMode("WorkflowMode", Float) = 1.0

	// Rotation with angle (in radians) and axis
	float3x3 AngleAxis3x3(float angle, float3 axis)
	{
	float c, s;
	sincos(angle, s, c);

	float t = 1 - c;
	float x = axis.x;
	float y = axis.y;
	float z = axis.z;

	// Copyright (c) 2016 StagPoint Software
	namespace StagPoint.Networking
	{
	using System;

	using UnityEngine;
	using UnityEngine.Networking;

	/// <summary>
	/// Provides some commonly-used functions for transferring compressed data over the network using

	vec3 hsv2rgb(vec3 c) {
	vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
	vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
	return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
	}

	const vec4 K = vec4(1., 2. / 3., 1. / 3., 3.);
	vec3 hsv2rgb(vec3 c)
	{
	// from http://lolengine.net/blog/2013/07/27/rgb-to-hsv-in-glsl


	using UnityEngine;
	using UnityEditor;
	using System.Collections;
	using System.IO;
	using System.Text.RegularExpressions;
	using System.Collections.Generic;
	using System;

	class SolutionFixer : AssetPostprocessor

	/*

	v2: Matt Rix pointed out there's an undocumented ONGeneratedCSProjectFiles() callback
	https://gist.github.com/MattRix/0bf8de88e16e8b494dbb

	v1: Still available in the gist history if you want a FileSystemWatcher solution!

	THE PROBLEM:

	- Unity constantly rewrites its .sln files whenever you rename/add/remove scripts