vassvik

Measuring Light

Light is measured in two ways. Radiometry measures the energy impinging on a sensor, and photometry attempts to qualitatively measure light to represent how a human observer experiences light. Radiometry is important when physical metrics must be preserved, such as in simulation tasks, and photometry is important in subjective tasks, such as selecting lights to illuminate a street.

Radiometric Units

Radiometric units measure the physical properties of light, independent of human perception. These units are based on the total energy or power of light across all wavelengths.

To better understand how these radiometric units are related, imagine a conceptual "cube" where each axis represents a dimension of measurement integration:

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

GPU Optimization for GameDev

Graphics Pipeline / GPU Architecture Overview

2011 - A trip through the Graphics Pipeline 2011
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
2020 - GPU ARCHITECTURE RESOURCES

OpenGL Black Bible

Author: Dale Weiler

Preface

The following is a writeup of the following things I've independently discovered or been told over the years on how to utilize OpenGL effectively. Not everything in here I gurantee to be factually correct - though several others share similar ideas as present here. Take these are your own peril, like everything else - nothing is absolute; so profile to be sure and check the standards if something here is incorrect. These things presented here I've come to accept as being a safe

API Design: Coroutines APIs (Janurary-2017)

I am currently dealing with a lot of libraries at work. Both third party as well as libraries written or being currently in process of being written by me. I absolutely love writing and working with libraries. Especially if they present or bring me to either a new or different approach to solve a problem. Or at least provide a different view.

Over time I noticed however that quite regulary we had to decide that we cannot use a third party library. Often it is the usual reason.

Atmosphere / Clouds Rendering

Research papers

Atmosphere

A fast, simple method to render sky color using gradients maps [[Abad06]]
A Framework for the Experimental Comparison of Solar and Skydome Illumination [[Kider14]]
A Method for Modeling Clouds based on Atmospheric Fluid Dynamics [[Miyazaki01]]
A Physically-Based Night Sky Model [[Jensen01]]

	Buffer<uint> Input;
	RWBuffer<uint> Output;

	//returns the index that this value should be moved to to sort the array
	uint CuteSort(uint value, uint laneIndex)
	{
	uint smallerValuesMask = 0;
	uint equalValuesMask = ~0;

	//don't need to test every bit if your value is constrained to a smaller range

	/*
	Loading C:\Users\connor\Downloads\models\lucy.obj.
	Duration: 1948.9ms
	Verts: 14027872
	Faces: 28055728
	Verts/s: 7197976.0
	Faces/s: 14395943.9
	MB/s: 605.4
	*/

	#ifndef __QUATERNION_INCLUDED__
	#define __QUATERNION_INCLUDED__

	#define QUATERNION_IDENTITY float4(0, 0, 0, 1)

	#ifndef PI
	#define PI 3.14159265359f
	#endif

	// Quaternion multiplication

	Latency Comparison Numbers
	--------------------------
	L1 cache reference/hit 1.5 ns 4 cycles
	Floating-point add/mult/FMA operation 1.5 ns 4 cycles
	L2 cache reference/hit 5 ns 12 ~ 17 cycles
	Branch mispredict 6 ns 15 ~ 20 cycles
	L3 cache hit (unshared cache line) 16 ns 42 cycles
	L3 cache hit (shared line in another core) 25 ns 65 cycles
	Mutex lock/unlock 25 ns
	L3 cache hit (modified in another core) 29 ns 75 cycles