render: rewrite PCF for spot lights to somehow fix PCSS directional lights

This reverts commit 8c1738334c.

examples/shadows/src/main.rs

@@ -5,7 +5,7 @@ use lyra_engine::{
         Action, ActionHandler, ActionKind, ActionMapping, ActionMappingId, ActionSource,
         InputActionPlugin, KeyCode, LayoutId, MouseAxis, MouseInput,
     },
-    math::{self, Angle, Quat, Transform, Vec3},
+    math::{self, Quat, Transform, Vec3},
     render::{
         graph::{ShadowCasterSettings, ShadowFilteringMode},
         light::{directional::DirectionalLight, PointLight, SpotLight},
@@ -184,6 +184,9 @@ fn setup_scene_plugin(game: &mut Game) {
             },
             ShadowCasterSettings {
                 filtering_mode: ShadowFilteringMode::Pcss,
+                pcf_samples_num: 64,
+                pcss_blocker_search_samples: 36,
+                constant_depth_bias_scale: 5.0,
                 ..Default::default()
             },
             light_tran,
@@ -235,29 +238,12 @@ fn setup_scene_plugin(game: &mut Game) {
             t,
             //cube_mesh.clone(),
         ));
-
-        /* world.spawn((
-            //cube_mesh.clone(),
-            PointLight {
-                enabled: true,
-                color: Vec3::new(0.278, 0.984, 0.0),
-                intensity: 2.0,
-                range: 9.0,
-                ..Default::default()
-            },
-            Transform::from_xyz(-0.5, 2.0, -5.0),
-        )); */
     }
 
     let mut camera = CameraComponent::new_3d();
-    //camera.transform.translation += math::Vec3::new(0.0, 2.0, 10.5);
     camera.transform.translation = math::Vec3::new(-1.0, -10.0, -1.5);
     camera.transform.rotate_x(math::Angle::Degrees(-27.0));
     camera.transform.rotate_y(math::Angle::Degrees(-90.0));
 
-    /* camera.transform.translation = math::Vec3::new(15.0, -8.0, 1.0);
-    camera.transform.rotate_x(math::Angle::Degrees(-27.0));
-    camera.transform.rotate_y(math::Angle::Degrees(90.0)); */
-
     world.spawn((camera, FreeFlyCamera::default()));
 }

lyra-game/src/render/graph/passes/shadows.rs

@@ -201,6 +201,17 @@ impl ShadowMapsPass {
         let has_shadow_settings = if are_settings_custom {
             1
         } else { 0 };
+        /* let (has_shadow_settings, pcf_samples_num, pcss_samples_num) = if are_settings_custom {
+            
+            (1, u.pcf_samples_num, u.pcss_blocker_search_samples)
+        } else {
+            (0, , 0)
+        }; */
+
+        /* shadow_settings.map(|ss| {
+            let u = ShadowSettingsUniform::new(ss.filtering_mode, ss.pcf_samples_num, ss.pcss_blocker_search_samples);
+            (1, u.pcf_samples_num, u.pcss_blocker_search_samples)
+        }).unwrap_or((0, 0, 0)); */
 
         let (start_atlas_idx, uniform_indices) = match light_type {
             LightType::Directional => {
@@ -256,27 +267,36 @@ impl ShadowMapsPass {
                 (atlas_index, indices)
             }
             LightType::Spotlight => {
-                // allocate a single frame in the shadow map atlas
+                let directional_size = SHADOW_SIZE * 4;
+                // directional lights require a single map, so allocate that in the atlas.
                 let atlas_index = atlas
-                    .pack(SHADOW_SIZE.x as _, SHADOW_SIZE.y as _)
+                    .pack(directional_size.x as _, directional_size.y as _)
                     .expect("failed to pack new shadow map into texture atlas");
                 let atlas_frame = atlas.texture_frame(atlas_index).expect("Frame missing");
 
                 let aspect = SHADOW_SIZE.x as f32 / SHADOW_SIZE.y as f32;
                 let projection = glam::Mat4::perspective_rh(
-                    //Angle::Degrees(90.0).to_radians(),
                     (light_half_outer_angle.unwrap() * 2.0).to_radians(),
                     aspect,
                     shadow_settings.near_plane,
                     shadow_settings.far_plane,
                 );
 
-                let light_trans = light_pos.translation;
-                let forward = light_pos.forward();
-                let up = light_pos.up();
-                let view = glam::Mat4::look_to_rh(light_trans, forward, up);
+                // honestly no clue why this works, but I got it from here and the results are good
+                // https://github.com/asylum2010/Asylum_Tutorials/blob/423e5edfaee7b5ea450a450e65f2eabf641b2482/ShaderTutors/43_ShadowMapFiltering/main.cpp#L323
+                /* let frustum_size = Vec2::new(0.5 * projection.col(0).x, 0.5 * projection.col(1).y);
+                // maybe its better to make this a vec2 on the gpu?
+                let size_avg = (frustum_size.x + frustum_size.y) / 2.0;
+                let light_size_uv = 0.2 * size_avg; */
 
-                let light_proj = projection * view;
+                let light_trans = light_pos.translation;
+                let look_view = glam::Mat4::look_at_rh(
+                    light_trans,
+                    light_trans + glam::vec3(1.0, 0.0, 0.0),
+                    glam::vec3(0.0, -1.0, 0.0),
+                );
+
+                let light_proj = projection * look_view;
 
                 let u = LightShadowUniform {
                     space_mat: light_proj,
@@ -666,30 +686,6 @@ impl Node for ShadowMapsPass {
             }
         }
 
-        for (entity, pos, shadow_settings, spot) in world.view_iter::<(
-            Entities,
-            &Transform,
-            Option<&ShadowCasterSettings>,
-            &SpotLight,
-        )>() {
-            if !self.depth_maps.contains_key(&entity) {
-                let (custom_settings, shadow_settings) = shadow_settings
-                    .map(|ss| (true, ss.clone()))
-                    .unwrap_or((false, settings));
-
-                let atlas_index = self.create_depth_map(
-                    &context.queue,
-                    LightType::Spotlight,
-                    entity,
-                    *pos,
-                    Some(spot.outer_cutoff),
-                    custom_settings,
-                    shadow_settings,
-                );
-                index_components_queue.push_back((entity, atlas_index));
-            }
-        }
-
         for (entity, pos, shadow_settings, _) in world.view_iter::<(
             Entities,
             &Transform,
@@ -714,6 +710,30 @@ impl Node for ShadowMapsPass {
             }
         }
 
+        for (entity, pos, shadow_settings, spot) in world.view_iter::<(
+            Entities,
+            &Transform,
+            Option<&ShadowCasterSettings>,
+            &SpotLight,
+        )>() {
+            if !self.depth_maps.contains_key(&entity) {
+                let (custom_settings, shadow_settings) = shadow_settings
+                    .map(|ss| (true, ss.clone()))
+                    .unwrap_or((false, settings));
+
+                let atlas_index = self.create_depth_map(
+                    &context.queue,
+                    LightType::Spotlight,
+                    entity,
+                    *pos,
+                    Some(spot.outer_cutoff),
+                    custom_settings,
+                    shadow_settings,
+                );
+                index_components_queue.push_back((entity, atlas_index));
+            }
+        }
+
         // now consume from the queue adding the components to the entities
         while let Some((entity, depth)) = index_components_queue.pop_front() {
             world.insert(
@@ -844,7 +864,7 @@ impl Node for ShadowMapsPass {
                         &frame,
                         light_depth_map.uniform_index[0] as _,
                     );
-                },
+                }
                 LightType::Point => {
                     pass.set_pipeline(&point_light_pipeline);
 
@@ -864,10 +884,9 @@ impl Node for ShadowMapsPass {
                             ui as _,
                         );
                     }
-                },
+                }
                 LightType::Spotlight => {
                     pass.set_pipeline(&pipeline);
-                    //pass.set_pipeline(&point_light_pipeline);
 
                     let frame = atlas
                         .texture_frame(light_depth_map.atlas_index)
@@ -882,7 +901,7 @@ impl Node for ShadowMapsPass {
                         &frame,
                         light_depth_map.uniform_index[0] as _,
                     );
-                }
+                },
             }
         }
     }
@@ -1051,17 +1070,35 @@ pub enum ShadowFilteringMode {
     None,
     /// Uses hardware features for 2x2 PCF.
     Pcf2x2,
-    #[default]
     Pcf,
-    /// Percentage-Closer Soft Shadows
-    /// https://developer.download.nvidia.com/shaderlibrary/docs/shadow_PCSS.pdf
-    /// 
-    /// PCSS is only implemented for directional lights. Use PCF for point and spot lights instead.
-    /// PCSS is expensive per-frame, so it has not been implemented for them. If you use this for
-    /// point and/or spot lights, the renderer will fall back to PCF.
+    #[default]
     Pcss,
 }
 
+/* #[derive(Debug, Copy, Clone)]
+pub struct ShadowSettings {
+    pub filtering_mode: ShadowFilteringMode,
+    /// How many PCF filtering samples are used per dimension.
+    ///
+    /// A value of 25 is common, this is maxed to 128.
+    pub pcf_samples_num: u32,
+    /// How many samples are used for the PCSS blocker search step.
+    ///
+    /// Multiple samples are required to avoid holes int he penumbra due to missing blockers.
+    /// A value of 25 is common, this is maxed to 128.
+    pub pcss_blocker_search_samples: u32,
+}
+
+impl Default for ShadowSettings {
+    fn default() -> Self {
+        Self {
+            filtering_mode: ShadowFilteringMode::default(),
+            pcf_samples_num: 25,
+            pcss_blocker_search_samples: 25,
+        }
+    }
+} */
+
 const PCF_SAMPLES_NUM_MAX: u32 = 128;
 const PCSS_SAMPLES_NUM_MAX: u32 = 128;
 

lyra-game/src/render/light/spotlight.rs

@@ -9,8 +9,6 @@ pub struct SpotLight {
     pub range: f32,
     pub intensity: f32,
     pub smoothness: f32,
-    /// Cutoff angle that specifies the light radius.
-    /// This is half of the light's FOV.
     pub cutoff: math::Angle,
     pub outer_cutoff: math::Angle,
 }

lyra-game/src/render/shaders/base.wgsl

@@ -182,6 +182,7 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
 
         if (light.light_ty == LIGHT_TY_DIRECTIONAL) {
             let shadow_u: LightShadowMapUniform = u_light_shadow[light.light_shadow_uniform_index[0]];
+            let frag_pos_light_space = shadow_u.light_space_matrix * vec4<f32>(in.world_position, 1.0);
 
             let shadow = calc_shadow_dir_light(in.world_position, in.world_normal, light_dir, light);
             light_res += blinn_phong_dir_light(in.world_position, in.world_normal, light, u_material, specular_color, shadow);
@@ -189,7 +190,7 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
             let shadow = calc_shadow_point_light(in.world_position, in.world_normal, light_dir, light, atlas_dimensions);
             light_res += blinn_phong_point_light(in.world_position, in.world_normal, light, u_material, specular_color, shadow);
         } else if (light.light_ty == LIGHT_TY_SPOT) {
-            let shadow = calc_shadow_spot_light(in.world_position, in.world_normal, light_dir, light);
+            let shadow = calc_shadow_spot_light(in.world_position, in.world_normal, light_dir, light, atlas_dimensions);
             light_res += blinn_phong_spot_light(in.world_position, in.world_normal, light, u_material, specular_color, shadow);
         }
     }
@@ -293,12 +294,12 @@ fn calc_shadow_dir_light(world_pos: vec3<f32>, world_normal: vec3<f32>, light_di
     }
     // PCSS
     else if pcf_samples_num > 0u && pcss_blocker_search_samples > 0u {
-        shadow = pcss_dir_light(xy_remapped, current_depth, i32(pcss_blocker_search_samples), i32(pcf_samples_num), map_data);
+        shadow = pcss_dir_light(xy_remapped, current_depth, map_data);
     }
     // only PCF
     else if pcf_samples_num > 0u {
         let texel_size = 1.0 / f32(map_data.atlas_frame.width);
-        shadow = pcf_dir_light(xy_remapped, current_depth, map_data, i32(pcf_samples_num), texel_size);
+        shadow = pcf_dir_light(xy_remapped, current_depth, map_data, texel_size);
     }
     // no filtering
     else {
@@ -352,13 +353,13 @@ fn to_atlas_frame_coords(shadow_u: LightShadowMapUniform, coords: vec2<f32>, saf
 }
 
 /// Find the average blocker distance for a directiona llight
-fn find_blocker_distance_dir_light(tex_coords: vec2<f32>, search_samples: i32, receiver_depth: f32, bias: f32, shadow_u: LightShadowMapUniform) -> vec2<f32> {
+fn find_blocker_distance_dir_light(tex_coords: vec2<f32>, receiver_depth: f32, bias: f32, shadow_u: LightShadowMapUniform) -> vec2<f32> {
     let search_width = search_width(shadow_u.near_plane, shadow_u.light_size_uv, receiver_depth);
 
     var blockers = 0;
     var avg_dist = 0.0;
-    //let samples = i32(u_shadow_settings.pcss_blocker_search_samples);
-    for (var i = 0; i < search_samples; i++) {
+    let samples = i32(u_shadow_settings.pcss_blocker_search_samples);
+    for (var i = 0; i < samples; i++) {
         let offset_coords = tex_coords + u_pcss_poisson_disc[i] * search_width;
         let new_coords = to_atlas_frame_coords(shadow_u, offset_coords, false);
         let z = textureSampleLevel(t_shadow_maps_atlas, s_shadow_maps_atlas, new_coords, 0.0);
@@ -373,8 +374,8 @@ fn find_blocker_distance_dir_light(tex_coords: vec2<f32>, search_samples: i32, r
     return vec2<f32>(avg_dist / b, b);
 }
 
-fn pcss_dir_light(tex_coords: vec2<f32>, receiver_depth: f32, pcss_blocker_samples: i32, pcf_samples_num: i32, shadow_u: LightShadowMapUniform) -> f32 {
-    let blocker_search = find_blocker_distance_dir_light(tex_coords, pcss_blocker_samples, receiver_depth, 0.0, shadow_u);
+fn pcss_dir_light(tex_coords: vec2<f32>, receiver_depth: f32, shadow_u: LightShadowMapUniform) -> f32 {
+    let blocker_search = find_blocker_distance_dir_light(tex_coords, receiver_depth, 0.0, shadow_u);
 
     // If no blockers were found, exit now to save in filtering
     if blocker_search.y == 0.0 {
@@ -387,12 +388,13 @@ fn pcss_dir_light(tex_coords: vec2<f32>, receiver_depth: f32, pcss_blocker_sampl
 
     // PCF
     let uv_radius = penumbra_width * shadow_u.light_size_uv * shadow_u.near_plane / receiver_depth;
-    return pcf_dir_light(tex_coords, receiver_depth, shadow_u, pcf_samples_num, uv_radius);
+    return pcf_dir_light(tex_coords, receiver_depth, shadow_u, uv_radius);
 }
 
 /// Calculate the shadow coefficient using PCF of a directional light
-fn pcf_dir_light(tex_coords: vec2<f32>, test_depth: f32, shadow_u: LightShadowMapUniform, samples_num: i32, uv_radius: f32) -> f32 {
+fn pcf_dir_light(tex_coords: vec2<f32>, test_depth: f32, shadow_u: LightShadowMapUniform, uv_radius: f32) -> f32 {
     var shadow = 0.0;
+    let samples_num = i32(u_shadow_settings.pcf_samples_num);
     for (var i = 0; i < samples_num; i++) {
         let offset = tex_coords + u_pcf_poisson_disc[i] * uv_radius;
         let new_coords = to_atlas_frame_coords(shadow_u, offset, false);
@@ -439,10 +441,15 @@ fn calc_shadow_point_light(world_pos: vec3<f32>, world_normal: vec3<f32>, light_
         let region_coords = to_atlas_frame_coords(u, coords_2d, true);
         shadow = textureSampleCompareLevel(t_shadow_maps_atlas, s_shadow_maps_atlas_compare, region_coords, current_depth);
     }
-    // only PCF, PCSS is not supported so no need to check for it
+    // PCSS
+    else if pcf_samples_num > 0u && pcss_blocker_search_samples > 0u {
+        shadow = pcss_dir_light(coords_2d, current_depth, u);
+    }
+    // only PCF
     else if pcf_samples_num > 0u {
         let texel_size = 1.0 / f32(u.atlas_frame.width);
-        shadow = pcf_point_light(frag_to_light, current_depth, uniforms, pcf_samples_num, texel_size);
+        shadow = pcf_point_light(frag_to_light, current_depth, uniforms, pcf_samples_num, 0.007);
+        //shadow = pcf_point_light(coords_2d, current_depth, u, pcf_samples_num, texel_size);
     }
     // no filtering
     else {
@@ -476,21 +483,7 @@ fn pcf_point_light(tex_coords: vec3<f32>, test_depth: f32, shadow_us: array<Ligh
     return saturate(shadow);
 }
 
-fn pcf_spot_light(tex_coords: vec2<f32>, test_depth: f32, shadow_u: LightShadowMapUniform, samples_num: i32, uv_radius: f32) -> f32 {
-    var shadow = 0.0;
-    for (var i = 0; i < samples_num; i++) {
-        let offset = tex_coords + u_pcf_poisson_disc[i] * uv_radius;
-        let new_coords = to_atlas_frame_coords(shadow_u, offset, false);
-        
-        shadow += textureSampleCompare(t_shadow_maps_atlas, s_shadow_maps_atlas_compare, new_coords, test_depth);
-    }
-    shadow /= f32(samples_num);
-
-    // clamp shadow to [0; 1]
-    return saturate(shadow);
-}
-
-fn calc_shadow_spot_light(world_pos: vec3<f32>, world_normal: vec3<f32>, light_dir: vec3<f32>, light: Light) -> f32 {
+fn calc_shadow_spot_light(world_pos: vec3<f32>, world_normal: vec3<f32>, light_dir: vec3<f32>, light: Light, atlas_dimensions: vec2<i32>) -> f32 {
     let map_data: LightShadowMapUniform = u_light_shadow[light.light_shadow_uniform_index[0]];
     let frag_pos_light_space = map_data.light_space_matrix * vec4<f32>(world_pos, 1.0);
 
@@ -540,6 +533,21 @@ fn calc_shadow_spot_light(world_pos: vec3<f32>, world_normal: vec3<f32>, light_d
     return shadow;
 }
 
+/// Calculate the shadow coefficient using PCF of a directional light
+fn pcf_spot_light(tex_coords: vec2<f32>, test_depth: f32, shadow_u: LightShadowMapUniform, samples_num: i32, uv_radius: f32) -> f32 {
+    var shadow = 0.0;
+    for (var i = 0; i < samples_num; i++) {
+        let offset = tex_coords + u_pcf_poisson_disc[i] * uv_radius;
+        let new_coords = to_atlas_frame_coords(shadow_u, offset, false);
+        
+        shadow += textureSampleCompare(t_shadow_maps_atlas, s_shadow_maps_atlas_compare, new_coords, test_depth);
+    }
+    shadow /= f32(samples_num);
+
+    // clamp shadow to [0; 1]
+    return saturate(shadow);
+}
+
 fn debug_grid(in: VertexOutput) -> vec4<f32> {
     let tile_index_float: vec2<f32> = in.clip_position.xy / 16.0;
     let tile_index = vec2<u32>(floor(tile_index_float));
@@ -653,14 +661,13 @@ fn blinn_phong_spot_light(world_pos: vec3<f32>, world_norm: vec3<f32>, spot_ligh
     let distance = length(light_pos - world_pos);
     let attenuation = calc_attenuation(spot_light, distance);
 
-    ambient_color *= attenuation * spot_light.intensity * cone;
-    diffuse_color *= attenuation * spot_light.intensity * cone;
-    specular_color *= attenuation * spot_light.intensity * cone;
+    ambient_color *= attenuation * cone;
+    diffuse_color *= attenuation * cone;
+    specular_color *= attenuation * cone;
     //// end of spot light attenuation ////
 
-
     //return /*ambient_color +*/ diffuse_color + specular_color;
-    return (shadow * (diffuse_color + specular_color));
+    return (shadow * (diffuse_color + specular_color)) * spot_light.intensity;
 }
 
 fn calc_attenuation(light: Light, distance: f32) -> f32 {

lyra-game/src/render/shaders/shadows.wgsl

@@ -24,10 +24,15 @@ struct LightShadowMapUniform {
 
 @group(0) @binding(0)
 var<storage, read> u_light_shadow: array<LightShadowMapUniform>;
+/*@group(0) @binding(1)
+var<uniform> u_light_pos: vec3<f32>;
+@group(0) @binding(2)
+var<uniform> u_light_far_plane: f32;*/
 
 @group(1) @binding(0)
 var<uniform> u_model_transform_data: TransformData;
 
+
 struct VertexOutput {
     @builtin(position)
     clip_position: vec4<f32>,