Mesh with vertex joint attributes presumes existence of SkinnedMesh

When I looked at the Bevy (0.17.3) API for mesh skinning, I interpreted the `SkinnedMesh` component as the main part driving the behavior of drawing the mesh using joint index/weight attributes; that adding it effectively "opts into" it.

However, this doesn't seem to be the case: Rendering panics if I spawn a `Mesh3d` whose asset has `Mesh::ATTRIBUTE_JOINT_WEIGHT` & `_INDEX` and I haven't [yet] added `SkinnedMesh`.

Detailed error output

ERROR wgpu::backend::wgpu_core: Handling wgpu errors as fatal by default


thread '<unnamed>' (238332) panicked at <crates>/wgpu-26.0.1/src/backend/wgpu_core.rs:2391:18:

wgpu error: Validation Error

Caused by:

  In a CommandEncoder

    In a draw command, kind: MultiDrawIndirectCount

      The BindGroupLayout with 'mesh_layout' label of current set BindGroup with 'model_only_mesh_bind_group' label at index 2 is not compatible with the corresponding BindGroupLayout with 'skinned_mesh_layout' label of RenderPipeline with 'pbr_prepass_pipeline' label

        Expected entry with binding 1 not found in assigned bind group layout

stack backtrace:

   0: __rustc::rust_begin_unwind

             at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/std/src/panicking.rs:698:5

   1: core::panicking::panic_fmt

             at /rustc/ded5c06cf21d2b93bffd5d884aa6e96934ee4234/library/core/src/panicking.rs:80:14

   2: wgpu::backend::wgpu_core::default_error_handler

             at <crates>/wgpu-26.0.1/src/backend/wgpu_core.rs:659:5

   3: wgpu::backend::wgpu_core::ErrorSinkRaw::handle_error

             at <crates>/wgpu-26.0.1/src/backend/wgpu_core.rs:643:21

   4: wgpu::backend::wgpu_core::ContextWgpuCore::handle_error_inner

             at <crates>/wgpu-26.0.1/src/backend/wgpu_core.rs:298:14

   5: wgpu::backend::wgpu_core::ContextWgpuCore::handle_error_nolabel

             at <crates>/wgpu-26.0.1/src/backend/wgpu_core.rs:323:14

   6: <wgpu::backend::wgpu_core::CoreCommandEncoder as wgpu::dispatch::CommandEncoderInterface>::finish

             at <crates>/wgpu-26.0.1/src/backend/wgpu_core.rs:2391:18

   7: wgpu::api::command_encoder::CommandEncoder::finish

             at <crates>/wgpu-26.0.1/src/api/command_encoder.rs:56:33

   8: bevy_pbr::render::light::ShadowPassNode::run::{{closure}}

             at <crates>/bevy_pbr-0.17.3/src/render/light.rs:2341:37

   9: core::ops::function::FnOnce::call_once{{vtable.shim}}

             at <rust>/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5

  10: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once

             at <rust>/lib/rustlib/src/rust/library/alloc/src/boxed.rs:2005:9

  11: bevy_render::renderer::RenderContext::finish::{{closure}}::{{closure}}

             at <crates>/bevy_render-0.17.3/src/renderer/mod.rs:599:41

  12: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::future::future::Future>::poll

             at <rust>/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:299:9

  13: <futures_lite::future::CatchUnwind<F> as core::future::future::Future>::poll::{{closure}}

             at <crates>/futures-lite-2.6.1/src/future.rs:653:53

  14: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once

             at <rust>/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:274:9

  15: std::panicking::catch_unwind::do_call

             at <rust>/lib/rustlib/src/rust/library/std/src/panicking.rs:590:40

  16: std::panicking::catch_unwind

             at <rust>/lib/rustlib/src/rust/library/std/src/panicking.rs:553:19

  17: std::panic::catch_unwind

             at <rust>/lib/rustlib/src/rust/library/std/src/panic.rs:359:14

  18: <futures_lite::future::CatchUnwind<F> as core::future::future::Future>::poll

             at <crates>/futures-lite-2.6.1/src/future.rs:653:9

  19: <async_executor::AsyncCallOnDrop<Fut,Cleanup> as core::future::future::Future>::poll

             at <crates>/async-executor-1.13.3/src/lib.rs:1197:31

  20: async_task::raw::RawTask<F,T,S,M>::run::{{closure}}

             at <crates>/async-task-4.7.1/src/raw.rs:550:21

  21: core::ops::function::FnOnce::call_once

             at <rust>/lib/rustlib/src/rust/library/core/src/ops/function.rs:250:5

  22: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once

             at <rust>/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:274:9

  23: std::panicking::catch_unwind::do_call

             at <rust>/lib/rustlib/src/rust/library/std/src/panicking.rs:590:40

  24: std::panicking::catch_unwind

             at <rust>/lib/rustlib/src/rust/library/std/src/panicking.rs:553:19

  25: std::panic::catch_unwind

             at <rust>/lib/rustlib/src/rust/library/std/src/panic.rs:359:14

  26: async_task::raw::RawTask<F,T,S,M>::run

             at <crates>/async-task-4.7.1/src/raw.rs:549:23

  27: async_task::runnable::Runnable<M>::run

             at <crates>/async-task-4.7.1/src/runnable.rs:781:18

  28: async_executor::State::run::{{closure}}::{{closure}}

             at <crates>/async-executor-1.13.3/src/lib.rs:751:30

  29: <futures_lite::future::Or<F1,F2> as core::future::future::Future>::poll

             at <crates>/futures-lite-2.6.1/src/future.rs:454:46

  30: async_executor::State::run::{{closure}}

             at <crates>/async-executor-1.13.3/src/lib.rs:758:32

  31: async_executor::Executor::run::{{closure}}

             at <crates>/async-executor-1.13.3/src/lib.rs:344:34

  32: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::future::future::Future>::poll

             at <rust>/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:299:9

  33: <futures_lite::future::CatchUnwind<F> as core::future::future::Future>::poll::{{closure}}

             at <crates>/futures-lite-2.6.1/src/future.rs:653:53

  34: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once

             at <rust>/lib/rustlib/src/rust/library/core/src/panic/unwind_safe.rs:274:9

  35: std::panicking::catch_unwind::do_call

             at <rust>/lib/rustlib/src/rust/library/std/src/panicking.rs:590:40

  36: std::panicking::catch_unwind

             at <rust>/lib/rustlib/src/rust/library/std/src/panicking.rs:553:19

  37: std::panic::catch_unwind

             at <rust>/lib/rustlib/src/rust/library/std/src/panic.rs:359:14

  38: <futures_lite::future::CatchUnwind<F> as core::future::future::Future>::poll

             at <crates>/futures-lite-2.6.1/src/future.rs:653:9

  39: bevy_tasks::task_pool::TaskPool::execute_global_scope::{{closure}}::{{closure}}

             at <crates>/bevy_tasks-0.17.3/src/task_pool.rs:526:22

  40: <futures_lite::future::Or<F1,F2> as core::future::future::Future>::poll

             at <crates>/futures-lite-2.6.1/src/future.rs:454:46

  41: bevy_tasks::task_pool::TaskPool::execute_global_scope::{{closure}}

             at <crates>/bevy_tasks-0.17.3/src/task_pool.rs:530:41

  42: bevy_tasks::task_pool::TaskPool::scope_with_executor_inner::{{closure}}

             at <crates>/bevy_tasks-0.17.3/src/task_pool.rs:457:89

  43: async_io::driver::block_on::{{closure}}

             at <crates>/async-io-2.6.0/src/driver.rs:204:53

  44: std::thread::local::LocalKey<T>::try_with

             at <rust>/lib/rustlib/src/rust/library/std/src/thread/local.rs:508:12

  45: std::thread::local::LocalKey<T>::with

             at <rust>/lib/rustlib/src/rust/library/std/src/thread/local.rs:472:20

  46: async_io::driver::block_on

             at <crates>/async-io-2.6.0/src/driver.rs:180:11

  47: bevy_tasks::task_pool::TaskPool::scope_with_executor_inner

             at <crates>/bevy_tasks-0.17.3/src/task_pool.rs:413:13

  48: bevy_tasks::task_pool::TaskPool::scope::{{closure}}

             at <crates>/bevy_tasks-0.17.3/src/task_pool.rs:316:18

  49: std::thread::local::LocalKey<T>::try_with

             at <rust>/lib/rustlib/src/rust/library/std/src/thread/local.rs:508:12

  50: std::thread::local::LocalKey<T>::with

             at <rust>/lib/rustlib/src/rust/library/std/src/thread/local.rs:472:20

  51: bevy_tasks::task_pool::TaskPool::scope

             at <crates>/bevy_tasks-0.17.3/src/task_pool.rs:315:31

  52: bevy_render::renderer::RenderContext::finish

             at <crates>/bevy_render-0.17.3/src/renderer/mod.rs:588:52

  53: bevy_render::renderer::graph_runner::RenderGraphRunner::run

             at <crates>/bevy_render-0.17.3/src/renderer/graph_runner.rs:83:82

  54: bevy_render::renderer::render_system

             at <crates>/bevy_render-0.17.3/src/renderer/mod.rs:43:15

  55: core::ops::function::FnMut::call_mut

             at <rust>/lib/rustlib/src/rust/library/core/src/ops/function.rs:166:5

  56: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut

             at <rust>/lib/rustlib/src/rust/library/core/src/ops/function.rs:298:21

  57: <Func as bevy_ecs::system::exclusive_function_system::ExclusiveSystemParamFunction<fn(F0) .> Out>>::run::call_inner

             at <crates>/bevy_ecs-0.17.3/src/system/exclusive_function_system.rs:270:21

  58: <Func as bevy_ecs::system::exclusive_function_system::ExclusiveSystemParamFunction<fn(F0) .> Out>>::run

             at <crates>/bevy_ecs-0.17.3/src/system/exclusive_function_system.rs:273:17

  59: <bevy_ecs::system::exclusive_function_system::ExclusiveFunctionSystem<Marker,Out,F> as bevy_ecs::system::system::System>::run_unsafe::{{closure}}

             at <crates>/bevy_ecs-0.17.3/src/system/exclusive_function_system.rs:135:33

  60: bevy_ecs::world::World::last_change_tick_scope

             at <crates>/bevy_ecs-0.17.3/src/world/mod.rs:3009:9

  61: <bevy_ecs::system::exclusive_function_system::ExclusiveFunctionSystem<Marker,Out,F> as bevy_ecs::system::system::System>::run_unsafe

             at <crates>/bevy_ecs-0.17.3/src/system/exclusive_function_system.rs:113:15

  62: bevy_ecs::system::system::System::run_without_applying_deferred

             at <crates>/bevy_ecs-0.17.3/src/system/system.rs:139:23

  63: bevy_ecs::system::system::System::run

             at <crates>/bevy_ecs-0.17.3/src/system/system.rs:119:24

note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

The above error repeats a few times, including for the 'pbr_opaque_mesh_pipeline' pipeline label, before ultimately triggering:

Encountered a panic in system `bevy_render::renderer::render_system`!


thread '<unnamed>' (238332) panicked at <crates>/wgpu-hal-26.0.6/src/vulkan/instance.rs:194:58:

Trying to destroy a SurfaceAcquireSemaphores that is still in use by a SurfaceTexture

A brief inspection suggests bevy_pbr selects a BindGroupLayoutDescriptor based on the presence of the attributes that is incompatible with the pipeline ultimately used to draw the mesh when there's no `SkinnedMesh`.

It seems to me that those attributes shouldn't be used at all if you don't add `SkinnedMesh`.

It might also be worth checking what happens if you have a `SkinnedMesh` with a `Mesh` that doesn't have the attributes.

---

This isn't actually blocking me, and I mention it more as a UX thing than a bug, since there's no defined behavior documented for this. Though that's not saying much, bevy_mesh::skinning could use more documentation 🙂

Start by reproducing the Mesh3d case with joint attributes but no SkinnedMesh, then inspect the bevy_pbr layout selection and the failing draw path reported in bevy_pbr/src/render/light.rs. Check both combinations mentioned in the issue, including SkinnedMesh without the attributes. Done means the invalid bind-group/pipeline combination no longer panics and the supported behavior is documented in bevy_mesh::skinning.

Written by the indexing model from the issue text.