JMS55
e1a0da0fa6
Meshlet LOD-compatible two-pass occlusion culling ( #12898 )
...
Keeping track of explicit visibility per cluster between frames does not
work with LODs, and leads to worse culling (using the final depth buffer
from the previous frame is more accurate).
Instead, we need to generate a second depth pyramid after the second
raster pass, and then use that in the first culling pass in the next
frame to test if a cluster would have been visible last frame or not.
As part of these changes, the write_index_buffer pass has been folded
into the culling pass for a large performance gain, and to avoid
tracking a lot of extra state that would be needed between passes.
Prepass previous model/view stuff was adapted to work with meshlets as
well.
Also fixed a bug with materials, and other misc improvements.
---------
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: atlas dostal <rodol@rivalrebels.com>
Co-authored-by: vero <email@atlasdostal.com>
Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
Co-authored-by: Robert Swain <robert.swain@gmail.com>
2024-04-28 05:30:20 +00:00
JMS55
6d6810c90d
Meshlet continuous LOD ( #12755 )
...
Adds a basic level of detail system to meshlets. An extremely brief
summary is as follows:
* In `from_mesh.rs`, once we've built the first level of clusters, we
group clusters, simplify the new mega-clusters, and then split the
simplified groups back into regular sized clusters. Repeat several times
(ideally until you can't anymore). This forms a directed acyclic graph
(DAG), where the children are the meshlets from the previous level, and
the parents are the more simplified versions of their children. The leaf
nodes are meshlets formed from the original mesh.
* In `cull_meshlets.wgsl`, each cluster selects whether to render or not
based on the LOD bounding sphere (different than the culling bounding
sphere) of the current meshlet, the LOD bounding sphere of its parent
(the meshlet group from simplification), and the simplification error
relative to its children of both the current meshlet and its parent
meshlet. This kind of breaks two pass occlusion culling, which will be
fixed in a future PR by using an HZB from the previous frame to get the
initial list of occluders.
Many, _many_ improvements to be done in the future
https://github.com/bevyengine/bevy/issues/11518 , not least of which is
code quality and speed. I don't even expect this to work on many types
of input meshes. This is just a basic implementation/draft for
collaboration.
Arguable how much we want to do in this PR, I'll leave that up to
maintainers. I've erred on the side of "as basic as possible".
References:
* Slides 27-77 (video available on youtube)
https://advances.realtimerendering.com/s2021/Karis_Nanite_SIGGRAPH_Advances_2021_final.pdf
*
https://blog.traverseresearch.nl/creating-a-directed-acyclic-graph-from-a-mesh-1329e57286e5
*
https://jglrxavpok.github.io/2024/01/19/recreating-nanite-lod-generation.html ,
https://jglrxavpok.github.io/2024/03/12/recreating-nanite-faster-lod-generation.html ,
https://jglrxavpok.github.io/2024/04/02/recreating-nanite-runtime-lod-selection.html ,
and https://github.com/jglrxavpok/Carrot
*
https://github.com/gents83/INOX/tree/master/crates/plugins/binarizer/src
* https://cs418.cs.illinois.edu/website/text/nanite.html
---------
Co-authored-by: Ricky Taylor <rickytaylor26@gmail.com>
Co-authored-by: vero <email@atlasdostal.com>
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: atlas dostal <rodol@rivalrebels.com>
Co-authored-by: Patrick Walton <pcwalton@mimiga.net>
2024-04-23 21:43:53 +00:00
JMS55
4f20faaa43
Meshlet rendering (initial feature) ( #10164 )
...
# Objective
- Implements a more efficient, GPU-driven
(https://github.com/bevyengine/bevy/issues/1342 ) rendering pipeline
based on meshlets.
- Meshes are split into small clusters of triangles called meshlets,
each of which acts as a mini index buffer into the larger mesh data.
Meshlets can be compressed, streamed, culled, and batched much more
efficiently than monolithic meshes.
# Misc
* Future work: https://github.com/bevyengine/bevy/issues/11518
* Nanite reference:
https://advances.realtimerendering.com/s2021/Karis_Nanite_SIGGRAPH_Advances_2021_final.pdf
Two pass occlusion culling explained very well:
https://medium.com/@mil_kru/two-pass-occlusion-culling-4100edcad501
---------
Co-authored-by: Ricky Taylor <rickytaylor26@gmail.com>
Co-authored-by: vero <email@atlasdostal.com>
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: atlas dostal <rodol@rivalrebels.com>
2024-03-25 19:08:27 +00:00
