Retain RenderMeshInstance and MeshInputUniform data from frame to frame.
#16385
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
frame. This commit moves the front end of the rendering pipeline to a retained model when GPU preprocessing is in use (i.e. by default, except in constrained environments). `RenderMeshInstance` and `MeshUniformData` are stored from frame to frame and are updated only for the entities that changed state. This was rather tricky and requires some careful surgery to keep the data valid in the case of removals. This patch is built on top of Bevy's change detection. Generally, this worked, except that `ViewVisibility` isn't currently properly tracked. Therefore, this commit adds proper change tracking for `ViewVisibility`. Doing this required adding a new system that runs after all `check_visibility` invocations, as no single `check_visibility` invocation has enough global information to detect changes. On the Bistro exterior scene, with all textures forced to opaque, this patch improves steady-state `extract_meshes_for_gpu_building` from 93.8us to 34.5us and steady-state `collect_meshes_for_gpu_building` from 195.7us to 4.28us. Altogether this constitutes an improvement from 290us to 38us, which is a 7.46x speedup.
pcwalton
added
A-Rendering
pcwalton
added
S-Needs-Review
tim-blackbird
approved these changes
Dec 5, 2024
JMS55
reviewed
Dec 5, 2024
JMS55
approved these changes
Dec 5, 2024
There was a problem hiding this comment.
Generally approve.
Some followups I think we should do in the future (nothing to do this with this PR):
- Hookup MeshletMesh to this API too (it already uses MeshUniform, but it doesn't use the existing queuing system)
- Switch to writing indices into the mesh uniforms per view, instead of copying the uniforms
- Experiment with using entities again instead of resources for storing data
- Rename MeshUniform to MeshInstanceData or something better
| GpuCulling { | ||
| /// Stores GPU data for each entity that became visible or changed in | ||
| /// such a way that necessitates updating the [`MeshInputUniform`] (e.g. | ||
| /// changed transform). |
There was a problem hiding this comment.
The fields of each variant are identical, right? Can we pull this out to a new type?
There was a problem hiding this comment.
Almost, the gpu culling side additionally needs MeshCullingData.
The removed vec could be shared but that would cause a decent bit of churn. Doesn't seem worthwhile
There was a problem hiding this comment.
Ah damn I thought I must have missed something. Agreed, lets leave it.
pcwalton
added
S-Ready-For-Final-Review
ecoskey
pushed a commit
to ecoskey/bevy
that referenced
this pull request
Jan 6, 2025
… frame. (bevyengine#16385) This commit moves the front end of the rendering pipeline to a retained model when GPU preprocessing is in use (i.e. by default, except in constrained environments). `RenderMeshInstance` and `MeshUniformData` are stored from frame to frame and are updated only for the entities that changed state. This was rather tricky and requires some careful surgery to keep the data valid in the case of removals. This patch is built on top of Bevy's change detection. Generally, this worked, except that `ViewVisibility` isn't currently properly tracked. Therefore, this commit adds proper change tracking for `ViewVisibility`. Doing this required adding a new system that runs after all `check_visibility` invocations, as no single `check_visibility` invocation has enough global information to detect changes. On the Bistro exterior scene, with all textures forced to opaque, this patch improves steady-state `extract_meshes_for_gpu_building` from 93.8us to 34.5us and steady-state `collect_meshes_for_gpu_building` from 195.7us to 4.28us. Altogether this constitutes an improvement from 290us to 38us, which is a 7.46x speedup.   This patch is only lightly tested and shouldn't land before 0.15 is released anyway, so I'm releasing it as a draft.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This commit moves the front end of the rendering pipeline to a retained model when GPU preprocessing is in use (i.e. by default, except in constrained environments).
RenderMeshInstanceandMeshUniformDataare stored from frame to frame and are updated only for the entities that changed state. This was rather tricky and requires some careful surgery to keep the data valid in the case of removals.This patch is built on top of Bevy's change detection. Generally, this worked, except that
ViewVisibilityisn't currently properly tracked. Therefore, this commit adds proper change tracking forViewVisibility. Doing this required adding a new system that runs after allcheck_visibilityinvocations, as no singlecheck_visibilityinvocation has enough global information to detect changes.On the Bistro exterior scene, with all textures forced to opaque, this patch improves steady-state
extract_meshes_for_gpu_buildingfrom 93.8us to 34.5us and steady-statecollect_meshes_for_gpu_buildingfrom 195.7us to 4.28us. Altogether this constitutes an improvement from 290us to 38us, which is a 7.46x speedup.This patch is only lightly tested and shouldn't land before 0.15 is released anyway, so I'm releasing it as a draft.