[video member=cmuratori stream_platform=twitch stream_username=handmade_hero project=code title="Multiresolution Light Sampling" vod_platform=youtube id=yrqpqbbe948 annotator=Miblo]
[0:00][Recap and set the stage for the day working on the :lighting][:rendering :speech]
[1:37][:Run the game to show our current :lighting situation whose stability is dependent on the rays][:rendering]
[4:14][Wax lyrical on @serge_rgb's wonderful work on ~milton][:blackboard :speech]
[5:49][:Lighting mods][:blackboard :optimisation :rendering]
[7:10][1. Stratified Sampling, including white noise][:blackboard :lighting :optimisation :prng :rendering :statistics]
[13:52][White vs Blue noise[ref
    site=Wikipedia
    page="Colors of noise"
    url=https://en.wikipedia.org/wiki/Colors_of_noise]][:blackboard :optimisation :prng :statistics]
[17:33][Light perception][:biology :blackboard]
[19:27][Blue noise, with a mention of the Witness Wednesday glass-planting system[ref
    site="Casey's Blog"
    page="Working on The Witness, Part 5"
    url=https://mollyrocket.com/casey/stream_0013.html]][:blackboard :lighting :prng :rendering :statistics]
[21:47][Performing stratified sampling][:blackboard :lighting :prng :rendering :statistics]
[25:18][2. "Multires sampling"][:blackboard :lighting :optimisation :rendering :statistics]
[28:46][3. "Bidirectional sampling"][:blackboard :lighting :optimisation :rendering :statistics]
[31:52][Make PlayWorld() generate 16 screens][:"procedural generation"]
[32:23][:Run the game and inspect the profiler, with the determination to get multiresolution sampling working][:lighting :performance :statistics :rendering]
[34:11][Read through the current :lighting code with a view to implementing multiresolution sampling, with synthetic light indices for neighbouring spatial partitions to use][:statistics :optimisation :rendering :research]
[38:46][Introduce the notion of an ExtendedPointCount in lighting_solution, to store synthetic :lighting data][:optimisation :statistic :rendering]
[45:27][Producing the data for the synthetic :lighting elements][:blackboard :geometry :rendering][quote 613]
[49:48][Make SplitBox() produce the extended :lighting points from the average of all points in their box][:geometry :rendering]
[1:02:15][:Run the game to see the total :lighting solution, and determine to produce some :"debug visualisation" of the spatial hierarchy][:geometry :rendering]
[1:04:20][Introduce OutputLightingPointsRecurse() to produce :"debug visualisation" for the :lighting system's entire spatial hierarchy][:geometry :rendering]
[1:10:47][Step in to OutputLightingPoints() to realise that we are indirected][:lighting :rendering :run]
[1:13:33][Make OutputLightingPoints() and SplitBox() use GetBox()][:geometry :lighting :rendering]
[1:15:11][:Run the game to see our :lighting :"debug visualisation"][:rendering]
[1:16:06][Make OutputLightingPointsRecurse() size the :"debug visualisation" :lighting boxes proportionally to their depth in the hierarchy][:geometry :rendering]
[1:20:06][:Run the game to see our proportionally-sized :lighting :"debug visualisation"][:geometry :rendering]
[1:21:01][Provide the ability in UpdateAndRenderWorld() to adjust the depth hierarchy][:"debug visualisation" :"input handling" :lighting :rendering]
[1:22:15][:Run the game and inspect our entire :lighting hierarchy][:"debug visualisation" :rendering]
[1:24:03][Make SplitBox() set the AccumulatedPPS to the InitialPPS][:"debug visualisation" :geometry :lighting :rendering]
[1:25:31][:Run the game and inspect our entire :lighting hierarchy][:"debug visualisation" :geometry :rendering]
[1:27:06][Prevent OutputLightingPointsRecurse() from including the emission of a childless light source][:"debug visualisation" :geometry :lighting :rendering]
[1:27:37][:Run the game to see that that doesn't fix our problem][:"debug visualisation" :geometry :lighting :rendering]
[1:32:14][Enable RayCastRecurse() to recurse to a given depth][:geometry :lighting :optimisation :rendering]
[1:33:35][:Run the game and watch the RayCastBoxCount while adjusting the depth in RayCastRecurse()][:lighting :optimisation :rendering]
[1:35:01][Make PlayWorld() create larger rooms][:"procedural generation"]
[1:35:33][:Run the game and again watch the RayCastBoxCount while adjusting the depth in RayCastRecurse()][:lighting :optimisation :rendering]
[1:38:29][Step in to LightingTest() to inspect the PointCount][:"debug system" :lighting :rendering :run]
[1:40:08][Make LightingTest() use a temporary variable for the PointCount before giving it to the DEBUG_VALUE][:"debug system"]
[1:40:31][:Run the game to determine that we have a bug in how we output u16s][:"debug system"]
[1:40:37][Add padding in lighting_solution after PointCount][:"debug system"]
[1:41:46][:Run the game to see that that fixes it][:"debug system"]
[1:42:37][Add a u16 handler in DEBUGValueSetEventData][:"debug system"]
[1:45:48][:Run the game to see that our PointCount is displayed correctly, but that our RayCastBoxCount seems to be too high][:"debug system" :"debug visualisation" :geometry]
[1:49:42][Augment lighting_solution with some more meaningful counters][:"debug system" :lighting :rendering]
[1:56:44][:Run the game and inspect :lighting data in the profiler][:performance :rendering]
[1:58:13][Force RayCastRecurse() never to recurse][:geometry :lighting :rendering]
[1:58:30][:Run the game to see that TotalPartitionsTested did not go down much][:geometry :lighting :performance :rendering]
[2:00:24][Read carefully through RayCastRecurse()][:geometry :lighting :rendering :research]
[2:01:36][:Run the game and watch the TotalLeavesTested when recursing or not][:geometry :lighting :rendering]
[2:02:52][Try making PlayWorld() create more layers][:"procedural generation"]
[2:04:46][:Run the game and now watch TotalLeavesTested() when recursing or not, to see that, when it doesn't recurse, it goes down much more now that there is a layer of :geometry above use][:lighting :performance :rendering]
[2:07:28][Q&A][:speech]
[2:09:03][@jamoflaw][Q: Can you explain why was the debug output behaving odd with u16s?][:"debug system"]
[2:12:47][@mathdaemon][Q: How likely is a lighting system GPU port still?][:hardware]
[2:13:19][@graemephi][Q: (Off-topic) Did you ever find out if it's necessary for CPUs to have named registers?][:hardware]
[2:15:38][@ataradov][Look at Mill CPU. It has no registers, but it is also a vaporware as far as physical implementations go][:hardware]
[2:17:21][@longboolean][Q: Do you think arranging pixels on LCD monitors in a blue noise pattern would be an improvement visually, I assume the costs to manufacture would sky rocket, or are we just better off making the pixels smaller?][:prng]
[2:18:20][@ataradov][Q: :Memory is slow]
[2:18:35][Close down][:speech]
[/video]