Constantine Galkin wiseConst

What is "Work Expansion"

In a GPU-driven renderer, "work expansion" is a commonly occurring problem. "Work Expansion" means that a single item of work spawns N following work items. Typically one work item will be executed by one shader thread/invocation.

An example for work expansion is gpu driven meshlet culling following mesh culling. In this example a "work item" is culling a mesh, where each mesh cull work item spawns N following meshlet cull work items.

There are many diverse cases of this problem and many solutions. Some are trivial to solve, for example, when N (how many work items are spawned) is fixed.

Computer Graphics Programming Resources

List of freely available resources to study computer graphics programming.

Basic Path

The Sane Rendering Manifesto

The goal of this manifesto is to provide an easy to follow and reasonable rules that realtime and video game renderers can follow.

These rules highly prioritize image clarity/stability and pleasant gameplay experience over photorealism and excess graphics fidelity.

Keep in mind that shipping a game has priority over everything else and it is allowed to break the rules of the manifesto when there are no other good options in order to ship the game.

Do not use dynamic resolution.

code

2022 "How Parameters Drive the Particle Effects of 'Forza Horizon 5'": https://www.youtube.com/watch?v=8Pk-yAp7J_8
2021 "Blowing from the West: Simulating Wind in 'Ghost of Tsushima'" https://www.youtube.com/watch?v=d61_o4CGQd8
2018 "Beyond Emitters: Shader and Surface Driven GPU Particle FX Techniques" https://www.youtube.com/watch?v=yG4ChOPyC-4
"Instancing and OIT in total war: Three kingdoms" https://www.intel.com/content/dam/develop/external/us/en/documents/instancing-and-oit-in-total-war-three-kingdoms.pdf (video: https://www.gdcvault.com/play/1026177/Instancing-and-Order-Independent-Transparency )
2018 "Frostbite GPU Emitter Graph System": https://www.ea.com/frostbite/news/frostbite-gpu-emitter-graph-system
2016 "Modern GPU particle systems in Alienation" https://www.youtube.com/watch?v=ARzl0d5a3UQ
2014 "compute-based gpu particle systems", amd https://www.gdcvault.com/play/1020002/Advanced-Visual-Effects-with-DirectX
2014 "The InFAMOUS: Second Son Particle System Architecture" h

From time to time I receive questions on the depth aware upsampling mentioned in the INSIDE-rendering presentation: https://loopit.dk/rendering_inside.pdf#page=39

The goal of this technique is to take the texture-output from a half-resolution pass, containing the results of sampling volumetric fog - and scale it up to full resolution. This presents two challenges:

Making sure samples from the low-resolution buffer, do not spill on top of foreground objects in the high-resolution buffer
Making sure the samples in the volumetric fog can be properly accumulated by TAA after upsampling

rasterisation

Index

This list is an attempt to collect as many free resources about computer graphics- / rendering- techniques, game- / render-engine architecture and optimization techniques. This list doesn't contain every resource that is out there so it'll be expanded in time whenever I find another resource that may help one person or the other.

	#version 450

	// 2D Polyhedral Bounds of a Clipped, Perspective-Projected 3D Sphere. Michael Mara, Morgan McGuire. 2013
	bool projectSphereView(vec3 c, float r, float znear, float P00, float P11, out vec4 aabb)
	{
	if (c.z < r + znear) return false;

	vec3 cr = c * r;
	float czr2 = c.z * c.z - r * r;

	// Copyright (c) 2023 Tomasz Stachowiak
	//
	// This contribution is dual licensed under EITHER OF
	//
	// Apache License, Version 2.0, (http://www.apache.org/licenses/LICENSE-2.0)
	// MIT license (http://opensource.org/licenses/MIT)
	//
	// at your option.

	#include "/inc/frame_constants.hlsl"

	Вопросы на rendering engineer Huawei

	- в чем разница между forward и deferred rendering? Какие плюсы и минусы у каждого из двух подходов (производительность / ограничения)
	- какие способы рендерить прозрачную геометрию вы знаете?
	- что такое алиасинг? Из-за чего он происходит? Какие есть алгоритмы антиалиасинга? Как реализован встроенный MSAA и чем он лучше SSAA?
	- как работает TAA и какие дефекты он вызывает?

	- как оптимально рисовать большое число объектов на экране? Какие есть способы отсечения? (на GPU и CPU)
	- как работает Kd-дерево, bvh, bsp? Какая у них асимптотика и от чего она зависит?
	- для чего нужны mip-уровни текстур и фильтрация текстур?