Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Meshlet tracking issue #11518

Open
JMS55 opened this issue Jan 24, 2024 · 2 comments
Open

Meshlet tracking issue #11518

JMS55 opened this issue Jan 24, 2024 · 2 comments
Assignees
@JMS55
Labels
A-Rendering Drawing game state to the screen C-Feature A new feature, making something new possible

Comments

@JMS55
Copy link
Contributor

JMS55 commented Jan 24, 2024 •
edited
Loading

Current TODOs🔥:

  • Figure out how to avoid tiny meshlets in the DAG (go through each step one by one in the first LOD and visualize the results)
  • Cleanup CPU code, improve CPU performance, and add more GPU debug group labels
  • Fix HIZ generation
  • Hierarchical culling (maybe persistent threads, maybe separate dispatches)

Low priority:

  • Single set of passes to render all views at once
  • Upload instance uniforms only for changed entities (and see if we can shrink the size too)
  • Instance culling
  • Compute-based material shading
  • Variable-rate shading (compute shader based)
  • LOD bias for shadow views
  • Multithread parts of MeshletMesh::from_mesh() maybe? (could use rayon)
  • Streaming
  • Meshlet triangle compression
  • Disk-oriented compression
  • Automatic quantization factor (read the gpuopen article)
  • UV-aware LOD selection
  • Normal and UV compression
  • Multi-mesh simplification with meshlets having more than 1 possible material

Tooling:

  • Debug stats + visualizations
  • Asset processor for mesh -> meshlet mesh conversion
  • UV arithmetic shader functions with derivative propagation
  • Docs
@JMS55 JMS55 added C-Feature A new feature, making something new possible A-Rendering Drawing game state to the screen labels Jan 24, 2024
@JMS55 JMS55 added this to the 0.14 milestone Jan 24, 2024
@JMS55 JMS55 self-assigned this Jan 24, 2024
@JMS55 JMS55 mentioned this issue Jan 24, 2024
Merged
github-merge-queue bot pushed a commit that referenced this issue Mar 25, 2024
@JMS55 @ricky26
@atlv24 @mockersf
Meshlet rendering (initial feature) (#10164)
4f20faa 
# Objective
- Implements a more efficient, GPU-driven
(#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.


![image](https://github.com/bevyengine/bevy/assets/47158642/cb2aaad0-7a9a-4e14-93b0-15d4e895b26a)

![image](https://github.com/bevyengine/bevy/assets/47158642/7534035b-1eb7-4278-9b99-5322e4401715)

# Misc
* Future work: #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 <[email protected]>
Co-authored-by: vero <[email protected]>
Co-authored-by: François <[email protected]>
Co-authored-by: atlas dostal <[email protected]>
@JMS55 JMS55 mentioned this issue Mar 27, 2024
Merged
@JMS55 JMS55 mentioned this issue Apr 5, 2024
Open
@JMS55 JMS55 changed the title Meshlet followup tracking issue Meshlet tracking issue Apr 5, 2024
github-merge-queue bot pushed a commit that referenced this issue Apr 23, 2024
@JMS55 @ricky26
@atlv24 @mockersf @pcwalton
Meshlet continuous LOD (#12755)
6d6810c 
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
#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


![image](https://github.com/bevyengine/bevy/assets/47158642/e40bff9b-7d0c-4a19-a3cc-2aad24965977)

![image](https://github.com/bevyengine/bevy/assets/47158642/442c7da3-7761-4da7-9acd-37f15dd13e26)

---------

Co-authored-by: Ricky Taylor <[email protected]>
Co-authored-by: vero <[email protected]>
Co-authored-by: François <[email protected]>
Co-authored-by: atlas dostal <[email protected]>
Co-authored-by: Patrick Walton <[email protected]>
@JMS55 JMS55 removed this from the 0.14 milestone May 14, 2024
@JMS55 JMS55 mentioned this issue Aug 8, 2024
Closed
@JMS55 JMS55 moved this to Large Projects in @JMS55 Bevy Plans Dec 5, 2024
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees

@JMS55 JMS55

Labels
A-Rendering Drawing game state to the screen C-Feature A new feature, making something new possible
Projects
None yet
Milestone
No milestone
Development

No branches or pull requests
2 participants
@JMS55 and others