Motion vector animated mesh

crates/bevy_core_pipeline/src/lib.rs

@@ -54,13 +54,16 @@ use crate::{
     fullscreen_vertex_shader::FULLSCREEN_SHADER_HANDLE,
     fxaa::FxaaPlugin,
     msaa_writeback::MsaaWritebackPlugin,
-    prepass::{DeferredPrepass, DepthPrepass, MotionVectorPrepass, NormalPrepass},
+    prepass::{
+        AnimatedMeshMotionVectors, DeferredPrepass, DepthPrepass, MotionVectorPrepass,
+        NormalPrepass,
+    },
     tonemapping::TonemappingPlugin,
     upscaling::UpscalingPlugin,
 };
 use bevy_app::{App, Plugin};
 use bevy_asset::load_internal_asset;
-use bevy_render::prelude::Shader;
+use bevy_render::{prelude::Shader, RenderApp};
 
 #[derive(Default)]
 pub struct CorePipelinePlugin;
@@ -91,4 +94,10 @@ impl Plugin for CorePipelinePlugin {
                 CASPlugin,
             ));
     }
+
+    fn finish(&self, app: &mut App) {
+        if let Some(render_app) = app.get_sub_app_mut(RenderApp) {
+            render_app.init_resource::<AnimatedMeshMotionVectors>();
+        }
+    }
 }

crates/bevy_core_pipeline/src/prepass/mod.rs

@@ -30,6 +30,7 @@ pub mod node;
 use std::ops::Range;
 
 use bevy_asset::AssetId;
+use bevy_derive::Deref;
 use bevy_ecs::prelude::*;
 use bevy_reflect::Reflect;
 use bevy_render::{
@@ -61,6 +62,10 @@ pub struct MotionVectorPrepass;
 #[derive(Component, Default, Reflect)]
 pub struct DeferredPrepass;
 
+/// TODO: Docs
+#[derive(Resource, Default, Deref)]
+pub struct AnimatedMeshMotionVectors(pub bool);
+
 /// Textures that are written to by the prepass.
 ///
 /// This component will only be present if any of the relevant prepass components are also present.

crates/bevy_core_pipeline/src/taa/mod.rs

@@ -2,7 +2,7 @@ use crate::{
     core_3d::graph::{Core3d, Node3d},
     fullscreen_vertex_shader::fullscreen_shader_vertex_state,
     prelude::Camera3d,
-    prepass::{DepthPrepass, MotionVectorPrepass, ViewPrepassTextures},
+    prepass::{AnimatedMeshMotionVectors, DepthPrepass, MotionVectorPrepass, ViewPrepassTextures},
 };
 use bevy_app::{App, Plugin};
 use bevy_asset::{load_internal_asset, Handle};
@@ -54,6 +54,7 @@ impl Plugin for TemporalAntiAliasPlugin {
         };
         render_app
             .init_resource::<SpecializedRenderPipelines<TaaPipeline>>()
+            .insert_resource(AnimatedMeshMotionVectors(true))
             .add_systems(ExtractSchedule, extract_taa_settings)
             .add_systems(
                 Render,
@@ -123,8 +124,6 @@ pub struct TemporalAntiAliasBundle {
 ///
 /// [Currently](https://github.com/bevyengine/bevy/issues/8423) cannot be used with [`bevy_render::camera::OrthographicProjection`].
 ///
-/// Currently does not support skinned meshes and morph targets.
-/// There will probably be ghosting artifacts if used with them.
 /// Does not work well with alpha-blended meshes as it requires depth writing to determine motion.
 ///
 /// It is very important that correct motion vectors are written for everything on screen.

crates/bevy_pbr/src/prepass/mod.rs

@@ -438,13 +438,17 @@ where
             shader_defs.push("PREPASS_FRAGMENT".into());
         }
 
-        let bind_group = setup_morph_and_skinning_defs(
+        let (bind_group, animated_mesh_motion_vectors) = setup_morph_and_skinning(
             &self.mesh_layouts,
             layout,
             5,
             &key.mesh_key,
             &mut shader_defs,
             &mut vertex_attributes,
+            key.mesh_key
+                .contains(MeshPipelineKey::ANIMATED_SKIN_MOTION_VECTORS),
+            key.mesh_key
+                .contains(MeshPipelineKey::ANIMATED_MORPH_MOTION_VECTORS),
         );
         bind_group_layouts.insert(1, bind_group);
 
@@ -535,11 +539,7 @@ where
         };
 
         let mut push_constant_ranges = Vec::with_capacity(1);
-        if cfg!(all(
-            feature = "webgl",
-            target_arch = "wasm32",
-            not(feature = "webgpu")
-        )) {
+        if animated_mesh_motion_vectors {
             push_constant_ranges.push(PushConstantRange {
                 stages: ShaderStages::VERTEX,
                 range: 0..4,
@@ -712,6 +712,8 @@ pub fn queue_prepass_material_meshes<M: Material>(
     render_materials: Res<RenderAssets<PreparedMaterial<M>>>,
     render_material_instances: Res<RenderMaterialInstances<M>>,
     render_lightmaps: Res<RenderLightmaps>,
+    skins: Res<SkinUniform>,
+    morphs: Res<MorphUniform>,
     mut views: Query<
         (
             &ExtractedView,
@@ -833,6 +835,13 @@ pub fn queue_prepass_material_meshes<M: Material>(
                 mesh_key |= MeshPipelineKey::LIGHTMAPPED;
             }
 
+            if skins.previous_buffer.is_some() && motion_vector_prepass.is_some() {
+                mesh_key |= MeshPipelineKey::ANIMATED_SKIN_MOTION_VECTORS;
+            }
+            if morphs.previous_buffer.is_some() && motion_vector_prepass.is_some() {
+                mesh_key |= MeshPipelineKey::ANIMATED_MORPH_MOTION_VECTORS;
+            }
+
             let pipeline_id = pipelines.specialize(
                 &pipeline_cache,
                 &prepass_pipeline,

crates/bevy_pbr/src/prepass/prepass.wgsl

@@ -96,10 +96,14 @@ fn vertex(vertex_no_morph: Vertex) -> VertexOutput {
 #ifdef MOTION_VECTOR_PREPASS
     // Use vertex_no_morph.instance_index instead of vertex.instance_index to work around a wgpu dx12 bug.
     // See https://github.com/gfx-rs/naga/issues/2416
+#ifdef ANIMATED_MESH_MOTION_VECTORS
+    // TODO: Account for previous skin, morph, or skin+morph
+#else
     out.previous_world_position = mesh_functions::mesh_position_local_to_world(
         mesh_functions::get_previous_model_matrix(vertex_no_morph.instance_index),
         vec4<f32>(vertex.position, 1.0)
     );
+#endif // ANIMATED_MESH_MOTION_VECTORS
 #endif // MOTION_VECTOR_PREPASS
 
 #ifdef VERTEX_OUTPUT_INSTANCE_INDEX
@@ -136,6 +140,9 @@ fn fragment(in: VertexOutput) -> FragmentOutput {
     // range -2,2, so this needs to be scaled by 0.5. And the V direction goes
     // down where clip space y goes up, so y needs to be flipped.
     out.motion_vector = (clip_position - previous_clip_position) * vec2(0.5, -0.5);
+#ifdef ANIMATED_MESH_MOTION_VECTORS
+    out.motion_vector *= prepass_bindings::motion_vectors_mask;
+#endif // ANIMATED_MESH_MOTION_VECTORS
 #endif // MOTION_VECTOR_PREPASS
 
 #ifdef DEFERRED_PREPASS

crates/bevy_pbr/src/prepass/prepass_bindings.wgsl

@@ -9,4 +9,9 @@ struct PreviousViewUniforms {
 @group(0) @binding(2) var<uniform> previous_view_uniforms: PreviousViewUniforms;
 #endif // MOTION_VECTOR_PREPASS
 
+// Zero if the current mesh did not have skin/morph data available last frame, else one
+#ifdef ANIMATED_MESH_MOTION_VECTORS
+var<push_constant> motion_vectors_mask: f32;
+#endif
+
 // Material bindings will be in @group(2)