Jose Moreno josemorval

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.

Minimal D3D11

Minimal D3D11 reference implementation: An uncluttered Direct3D 11 setup + basic rendering primer and API familiarizer. Complete, runnable Windows application contained in a single function and laid out in a linear, step-by-step fashion that should be easy to follow from the code alone. ~200 LOC. No modern C++, OOP or (other) obscuring cruft. View on YouTube

Other gists in this series:

Minimal D3D11 part 2

Why I think Immediate Mode GUI is way to go for GameDev tools

This article is also available here.

Prerequisites

Before you continue, if you don't know what IMGUI is don't bother reading this post, just ignore it, don't write anything in comments section, etc. If you're curious about IMGUI see bottom of this post, otherwise continue whatever you were doing, this post it's not for you. Thanks!

If you know what IMGUI is, for context read following presentations and blog posts:

exFAT support on macOS seems to have some bugs because my external drives with exFAT formatting will randomly get corrupted.

If Disk Utility is unable to repair, consider trying this:

In Disk Utility, ensure that the drive is not mounted, eject it if it is mounted.
Use diskutil list to find the right drive id.
You want the id under the IDENTIFIER column, it should look like disk1s1
Run sudo fsck_exfat -d <id from above>. eg sudo fsck_exfat -d disk1s3
-d is debug so you'll see all your files output as they're processed.

OpenGL Development on OS X

While it's possible to download packages and install them manually, it's such a hassle. Fortunately for us, OS X has an unofficial package manager called http://brew.sh Let's install it. Open you Terminal and paste the following code:

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Great. Homebrew will automatically install packages to /usr/local. Conveniently, that directory is already in your include and link paths.

	#include <Windows.h>
	#include <d3d11.h>
	#include <iostream>
	#include <vector>
	#include <thread>
	#include <mutex>
	#include <d3dcompiler.h>

	#pragma comment(lib, "dxgi.lib")
	#pragma comment(lib, "d3d11.lib")

	#include <stdio.h>
	#include "bgfx/bgfx.h"
	#include "bgfx/platform.h"
	#include "bx/math.h"
	#include "GLFW/glfw3.h"
	#define GLFW_EXPOSE_NATIVE_WIN32
	#include "GLFW/glfw3native.h"

	#define WNDW_WIDTH 1600
	#define WNDW_HEIGHT 900

	// [src] https://github.com/ocornut/imgui/issues/123
	// [src] https://github.com/ocornut/imgui/issues/55

	// v1.22 - flip button; cosmetic fixes
	// v1.21 - oops :)
	// v1.20 - add iq's interpolation code
	// v1.10 - easing and colors
	// v1.00 - jari komppa's original

	#pragma once

	function R=fcn_RotationFromTwoVectors(A, B)
	% http://math.stackexchange.com/questions/180418/calculate-rotation-matrix-to-align-vector-a-to-vector-b-in-3d
	% R*v1=v2
	% v1 and v2 should be column vectors and 3x1

	%% Method 1
	% % 1. rotation vector
	% w=cross(v1,v2);
	% w=w/norm(w);
	% w_hat=fcn_GetSkew(w);

	(for %i in (*.mp4) do @echo file '%i') > mylist.txt

	ffmpeg -f concat -i mylist.txt -c copy output.mp4