Asynchronous Render List Generation and Frame-Independent Task Scheduling #2887

douira · 2024-11-22T20:00:25Z

Uses an octree to generate render lists independently of the, now asynchronous, slow graph search.

It runs the occlusion culler in a separate thread, which allows a large speedup in render list generation time. Correct culling results are ensured with a combination of different types of BFS, synchronous occlusion culling is used as a last resort if the camera teleports or moves extremely quickly.
Tasks are ordered based on a combination score of how long they've been pending, their distance from the camera, their type, and whether they're visible in the camera frustum. How many tasks can be scheduled is now independent of the frame rate and instead are limited based on their estimated duration and size.
There's an upload limit to ensure not too many tasks are submitted that will exceed the upload buffer's size. This isn't a hard limit and this PR doesn't implement a new way of handling task buffers, to avoid expanding the scope too far.

Testing has not shown regressions and generally frame rate has improved a little if a system was not limited by render list generation, and a lot if it was. (see testing thread)

Combination with #2886 will avoid even more of the asynchronous work since a graph search isn't necessary to schedule tasks with this PR. (will merge conflict, but should be easy to resolve)

Companion PR in Iris: IrisShaders/Iris#2539

Makes #2780 unnecessary, since the octree traversal is correctly ordered already.

…led yet, it just does the tree frustum test right after each bfs for testing purposes atm)

…g RenderSection objects, improve tree render list generation performance

…the tree, this greatly improves performance

…learer code

…ync bfs if there is very fast movement

…trees of varying accuracy to present as few sections as possible while not generating any errors when the camera is in motion.

… unloading of chunks

…ssues when the distance changes (for example under water)

- rebuild tasks are scheduled in a queue and pruned each frame - async culling tasks and results are classes in their own package - chunk rebuild tasks are prioritized based on their distance to the camera, their type, how long the task has been pending, and whether the section is currently visible (in the frustum) - generally cleaned up the update method in RSM

… its own "run" token

…the frame rate and section count when the world updates frequently

…plicity. also changed the frustum test to be before adding a section to the queue, and not after. from my measurements by looking at how long the OcclusionCuller call inside FrustumCullTask takes, this has no impact on performance.

…graph search culling

…ta all at once instead of for each section separately

… distance

…sk duration estimation

… douira:sharp-angle-traversal-occlusion

… variants of, add support for very tall worlds

… different tree implementation

…estimation, limit upload size based on previous mesh task result size or an estimate of it, the limit behavior changes depending on which type of upload buffer is used

… not automatically correctly ordered since they're not coming from a tree

This was referenced Nov 22, 2024

Integration with Asynchronous Render List Generation in Sodium IrisShaders/Iris#2539

Draft

Sort render lists for regions and sections after traversal (#2266) #2780

Merged

douira added 28 commits November 25, 2024 19:05

documentation cleanup

3b92c30

do frustum cull using a linear octree, WIP (BFS isn't actually decoup…

00df820

…led yet, it just does the tree frustum test right after each bfs for testing purposes atm)

use faster deinterleave with one fewer steps

02b17f5

implement front-to-back ordering during tree traversal

fee6d62

refactor plumbing between RSM and the chunk renderer to avoid touchin…

b7e5a63

…g RenderSection objects, improve tree render list generation performance

filter out sections that don't render anything before adding them to …

ce18b61

…the tree, this greatly improves performance

change tree read timing to average 100 samples

c62f82e

doesn't need to be public anymore

5aaf546

more reasonable flag mask ordering

9e38a45

take 2000 samples for measurement

afc4e3f

fix entity culling

39e6b05

split node iteration into separate loops, no change in performance, c…

23d0d5d

…learer code

use section coordinates for tree compatibility test

36f806e

remove unnecessary frustum test from entity culling

5b34db9

refactor update state management in RSM, add option to fall back to s…

7cbd724

…ync bfs if there is very fast movement

add better async bfs and tree management. It now calculates multiple …

0ea504d

…trees of varying accuracy to present as few sections as possible while not generating any errors when the camera is in motion.

prevent some NPEs that happen because of concurrency with loading and…

178b60d

… unloading of chunks

comment

bbfd763

increase tasks per thread per frame to 3, this seems to usually be ok

9804dbd

do render distance and fog culling in the tree traversal to prevent i…

43f00c8

…ssues when the distance changes (for example under water)

don't do frustum bfs if the frame was dirty to prevent unnecessary work

d1eec40

remove debug changes

57a0c91

fix issues with occlusion culling by making the graph search generate…

8fdcef0

… its own "run" token

introduce adaptive scheduling of cull tasks to reduce oscillation of …

bd72a20

…the frame rate and section count when the world updates frequently

formatting

ecddfea

improve documentation

9f97280

ideas

e2c99a7

douira added 25 commits November 25, 2024 19:57

added efficient approximative ray cast backed by a bitmap to improve …

76074db

…graph search culling

further improve speed of tree building by writing the reduced tree da…

8159957

…ta all at once instead of for each section separately

restore some info on the debug screen

79eb24a

fix section ordering

55443b7

improve how coordinate parameters are passed into section tree traversal

b497b58

fix issues when camera is outside of world

845e2ac

notes

c22b88b

fix crash when loading under water

fac7b80

fix missing world when fog distance changes, and flickering of render…

5ace795

… distance

remove unused best type variable

e9902ed

fix broken cancellation behavior on sync bfs

490cac0

implement frame rate independent task scheduling with effort-based ta…

7e279c2

…sk duration estimation

add angle-based section visibility path occlusion, cherry picked from…

8acb234

… douira:sharp-angle-traversal-occlusion

make inner tree in section tree static

4fbdcaf

refactor tree structures to be more self-contained and easier to make…

d2e4ba0

… variants of, add support for very tall worlds

fix rebase changes

32968fc

make traversable trees abstract so that they can be subclassed with a…

df2a2c6

… different tree implementation

ordering consistency

bb9a91c

fix incorrect multi forest size calculation

2d366fb

cleanup forest build distance handling

7e72271

fix section sorting by correcting the camera offset

802bc36

update todos

f966f8c

update debug info to be relevant and useful again

eca45dc

refactor job effort estimation, add category-based meshing task size …

158cd78

…estimation, limit upload size based on previous mesh task result size or an estimate of it, the limit behavior changes depending on which type of upload buffer is used

douira force-pushed the decoupled-frustum-test branch from 94885b5 to 158cd78 Compare November 25, 2024 19:12

sort render lists separately when doing sync rendering, since they're…

9443fbc

… not automatically correctly ordered since they're not coming from a tree

douira added the T-enhancement Type: Enhancement label Nov 26, 2024

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Asynchronous Render List Generation and Frame-Independent Task Scheduling #2887

Asynchronous Render List Generation and Frame-Independent Task Scheduling #2887

douira commented Nov 22, 2024 •

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Asynchronous Render List Generation and Frame-Independent Task Scheduling #2887

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Asynchronous Render List Generation and Frame-Independent Task Scheduling #2887

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douira commented Nov 22, 2024 • edited Loading

douira commented Nov 22, 2024 •

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