Claudia Doppioslash doppioslash

Quaternion Julia with Houdini VEX

Check it on ArtStation : Quaternion Julia.

Quaternion Julia is a type of 3D fractals created using 4D vectors called quaternions. These 4D vectors have a complex structure with one real value and three imaginary values. For more info about it, check this nice article from Paul Bourke.

For the project setup, I used the same one as in the Mandelbox with VEX project but with different code in the VolumeWrangler.

The main idea here is to use quaternions to change each voxel's position during the iterations. We will use a for loop to compute the terms of the

Where's The Luv?

An Examination of the CIELAB and CIELUV colorspaces.

It is exciting to see so many new color features for the CSS Color Module. There are nevertheless a couple items that resulted in a "raised eyebrow response". This Gist is mainly going to focus on one: the use of the LAB version of LCh instead of LUV LCh, which may be better suited for the task but appears to have been dismissed as if irrellevant.

I DISAGREE. Luv is in common use and very relevant, and LuvLCh or one of the several LuvLCh variants has distinct advantages over LabLCh for use cases such as choosing color for web content for displays.

Myth Destruction

In PIX, Select Target Process => Launch Win32 and set the following 2 entries according to where Canary / Chrome is installed:

Path to executable: "C:\Users\alexis\AppData\Local\Google\Chrome SxS\Application\chrome.exe"
Working directory: "C:\Users\alexis\AppData\Local\Google\Chrome SxS\Application"
Command line arguments: --disable-gpu-sandbox --disable-direct-composition
- You can add those arguments if you want to be able to see the disassembled shader code: --enable-dawn-features=emit_hlsl_debug_symbols,disable_symbol_renaming
Launch Suspended unchecked, Launch for GPU capture and Force D3D11On12 checked

Then click on "Launch".

Important: you should close all your Canary / Chrome windows/processes before clicking on the "Launch" button!

CUSTOM GAME ENGINES: A Small Study

WARNING: Article moved to separate repo to allow users contributions: https://github.com/raysan5/custom_game_engines

A couple of weeks ago I played (and finished) A Plague Tale, a game by Asobo Studio. I was really captivated by the game, not only by the beautiful graphics but also by the story and the locations in the game. I decided to investigate a bit about the game tech and I was surprised to see it was developed with a custom engine by a relatively small studio. I know there are some companies using custom engines but it's very difficult to find a detailed market study with that kind of information curated and updated. So this article.

Nowadays lots of companies choose engines like [Unreal](https:

Volumetric Clouds Resources List

A. Schneider, "Real-Time Volumetric Cloudscapes," in GPU Pro 7: Advanced Rendering Techniques, 2016, pp. 97-127. (Follow up presentations here, and here.)
S. Hillaire, "Physically Based Sky, Atmosphere and Cloud Rendering in Frostbite" in Physically Based Shading in Theory and Practice course, SIGGRAPH 2016. [video] [course notes] [scatter integral shadertoy]
[R. Högfeldt, "Convincing Cloud Rendering – An Implementation of Real-Time Dynamic Volumetric Clouds in Frostbite"](https://odr.chalmers.se/hand

	//
	// Lookup Tables for Transvoxel's Modified Marching Cubes
	//
	// Unlike the original paper (Marching Cubes: A High Resolution 3D Surface Construction Algorithm), these tables guarantee
	// a closed mesh "whose connected components are continuous and free of holes."
	//
	// Rotations are prioritised over inversions so that 3 of the 6 cases containing ambiguous faces are never added. 3 extra
	// cases are added as a post-process, overriding inverses through custom-build rotations to eliminate the rest.
	//
	// Uses the exact same co-ordinate system as https://gist.github.com/dwilliamson/c041e3454a713e58baf6e4f8e5fffecd

	// ==UserScript==
	// @name ls-twitter-embed
	// @namespace https://gist.github.com/cannibalox/e75fe2f2ecc0de08a13025a559e166cd
	// @version 0.1
	// @description fetch tweets from url
	// @author ported to logseq from louis kirsch's dynalist userscript
	// @match https://logseq.com/*
	// @grant GM.xmlHttpRequest
	// @run-at document-end
	// @require http://code.jquery.com/jquery-3.4.1.min.js

	Copyright (c) 2020- Juha Järvi

	Permission to use, copy, modify, and/or distribute this software for any
	purpose with or without fee is hereby granted.

	THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
	REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
	AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
	INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
	LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR

	import json
	import glob

	all_bookmarks = []
	md_file = open("bookmarks.md", "w+") # saving in markdown file, if no file exists using '+' creates one

	files = [file for file in glob.glob("JSONBookmarks/*")] # using glob to read all files from the folder
	for file_name in files:
	print(file_name)
	with open(file_name) as bk:

	struct vec3f {float x, y, z;};
	struct vec4f {float x, y, z, w;};
	struct mat44f {vec4f x, y, z, w;};

	//============================================================================
	// sphere_screen_extents
	//============================================================================
	// Calculates the exact screen extents xyzw=[left, bottom, right, top] in
	// normalized screen coordinates [-1, 1] for a sphere in view space. For
	// performance, the projection matrix (v2p) is assumed to be setup so that