Disable irradiance volumes on WebGL and WebGPU. (#11909)

They cause the number of texture bindings to overflow on those
platforms. Ultimately, we shouldn't unconditionally disable them, but
this fixes a crash blocking 0.13.

Closes #11885.

crates/bevy_pbr/src/light_probe/irradiance_volume.rs

@@ -157,6 +157,11 @@ use super::LightProbeComponent;
 pub const IRRADIANCE_VOLUME_SHADER_HANDLE: Handle<Shader> =
     Handle::weak_from_u128(160299515939076705258408299184317675488);
 
+/// On WebGL and WebGPU, we must disable irradiance volumes, as otherwise we can
+/// overflow the number of texture bindings when deferred rendering is in use
+/// (see issue #11885).
+pub(crate) const IRRADIANCE_VOLUMES_ARE_USABLE: bool = cfg!(not(target_arch = "wasm32"));
+
 /// The component that defines an irradiance volume.
 ///
 /// See [`crate::irradiance_volume`] for detailed information.

crates/bevy_pbr/src/light_probe/irradiance_volume.wgsl

@@ -8,6 +8,8 @@
     light_probes,
 };
 
+#ifdef IRRADIANCE_VOLUMES_ARE_USABLE
+
 // See:
 // https://advances.realtimerendering.com/s2006/Mitchell-ShadingInValvesSourceEngine.pdf
 // Slide 28, "Ambient Cube Basis"
@@ -50,3 +52,5 @@ fn irradiance_volume_light(world_position: vec3<f32>, N: vec3<f32>) -> vec3<f32>
     let NN = N * N;
     return (rgb_x * NN.x + rgb_y * NN.y + rgb_z * NN.z) * query_result.intensity;
 }
+
+#endif  // IRRADIANCE_VOLUMES_ARE_USABLE

crates/bevy_pbr/src/render/mesh.rs

@@ -50,6 +50,8 @@ use crate::render::{
 };
 use crate::*;
 
+use self::irradiance_volume::IRRADIANCE_VOLUMES_ARE_USABLE;
+
 use super::skin::SkinIndices;
 
 #[derive(Default)]
@@ -825,7 +827,7 @@ impl SpecializedMeshPipeline for MeshPipeline {
             shader_defs.push("ENVIRONMENT_MAP".into());
         }
 
-        if key.contains(MeshPipelineKey::IRRADIANCE_VOLUME) {
+        if key.contains(MeshPipelineKey::IRRADIANCE_VOLUME) && IRRADIANCE_VOLUMES_ARE_USABLE {
             shader_defs.push("IRRADIANCE_VOLUME".into());
         }
 
@@ -865,6 +867,10 @@ impl SpecializedMeshPipeline for MeshPipeline {
             shader_defs.push("MULTIPLE_LIGHT_PROBES_IN_ARRAY".into());
         }
 
+        if IRRADIANCE_VOLUMES_ARE_USABLE {
+            shader_defs.push("IRRADIANCE_VOLUMES_ARE_USABLE".into());
+        }
+
         let format = if key.contains(MeshPipelineKey::HDR) {
             ViewTarget::TEXTURE_FORMAT_HDR
         } else {

crates/bevy_pbr/src/render/mesh_view_bindings.rs

@@ -33,7 +33,10 @@ use environment_map::EnvironmentMapLight;
 
 use crate::{
     environment_map::{self, RenderViewEnvironmentMapBindGroupEntries},
-    irradiance_volume::{self, IrradianceVolume, RenderViewIrradianceVolumeBindGroupEntries},
+    irradiance_volume::{
+        self, IrradianceVolume, RenderViewIrradianceVolumeBindGroupEntries,
+        IRRADIANCE_VOLUMES_ARE_USABLE,
+    },
     prepass, FogMeta, GlobalLightMeta, GpuFog, GpuLights, GpuPointLights, LightMeta,
     LightProbesBuffer, LightProbesUniform, MeshPipeline, MeshPipelineKey, RenderViewLightProbes,
     ScreenSpaceAmbientOcclusionTextures, ShadowSamplers, ViewClusterBindings, ViewShadowBindings,
@@ -269,11 +272,14 @@ fn layout_entries(
     ));
 
     // Irradiance volumes
-    let irradiance_volume_entries = irradiance_volume::get_bind_group_layout_entries(render_device);
-    entries = entries.extend_with_indices((
-        (16, irradiance_volume_entries[0]),
-        (17, irradiance_volume_entries[1]),
-    ));
+    if IRRADIANCE_VOLUMES_ARE_USABLE {
+        let irradiance_volume_entries =
+            irradiance_volume::get_bind_group_layout_entries(render_device);
+        entries = entries.extend_with_indices((
+            (16, irradiance_volume_entries[0]),
+            (17, irradiance_volume_entries[1]),
+        ));
+    }
 
     // Tonemapping
     let tonemapping_lut_entries = get_lut_bind_group_layout_entries();
@@ -459,28 +465,32 @@ pub fn prepare_mesh_view_bind_groups(
                 }
             }
 
-            let irradiance_volume_bind_group_entries =
-                RenderViewIrradianceVolumeBindGroupEntries::get(
+            let irradiance_volume_bind_group_entries = if IRRADIANCE_VOLUMES_ARE_USABLE {
+                Some(RenderViewIrradianceVolumeBindGroupEntries::get(
                     render_view_irradiance_volumes,
                     &images,
                     &fallback_image,
                     &render_device,
-                );
+                ))
+            } else {
+                None
+            };
 
             match irradiance_volume_bind_group_entries {
-                RenderViewIrradianceVolumeBindGroupEntries::Single {
+                Some(RenderViewIrradianceVolumeBindGroupEntries::Single {
                     texture_view,
                     sampler,
-                } => {
+                }) => {
                     entries = entries.extend_with_indices(((16, texture_view), (17, sampler)));
                 }
-                RenderViewIrradianceVolumeBindGroupEntries::Multiple {
+                Some(RenderViewIrradianceVolumeBindGroupEntries::Multiple {
                     ref texture_views,
                     sampler,
-                } => {
+                }) => {
                     entries = entries
                         .extend_with_indices(((16, texture_views.as_slice()), (17, sampler)));
                 }
+                None => {}
             }
 
             let lut_bindings = get_lut_bindings(&images, &tonemapping_luts, tonemapping);

crates/bevy_pbr/src/render/mesh_view_bindings.wgsl

@@ -46,12 +46,14 @@
 #endif
 @group(0) @binding(15) var environment_map_sampler: sampler;
 
+#ifdef IRRADIANCE_VOLUMES_ARE_USABLE
 #ifdef MULTIPLE_LIGHT_PROBES_IN_ARRAY
 @group(0) @binding(16) var irradiance_volumes: binding_array<texture_3d<f32>, 8u>;
 #else
 @group(0) @binding(16) var irradiance_volume: texture_3d<f32>;
 #endif
 @group(0) @binding(17) var irradiance_volume_sampler: sampler;
+#endif
 
 // NB: If you change these, make sure to update `tonemapping_shared.wgsl` too.
 @group(0) @binding(18) var dt_lut_texture: texture_3d<f32>;