PCSS impl

bind/v4k.lua

@@ -1166,6 +1166,7 @@ typedef struct light_t {
     float variance_transition;
     float shadow_bias;
     float normal_bias;
+    float shadow_softness;
     bool cached;
     bool processed_shadows;
 } light_t;
@@ -1207,7 +1208,6 @@ typedef struct shadowmap_t {
     handle depth_texture;
     handle depth_texture_2d;
     int filter_size, window_size;
-    float offset_radius;
     handle offsets_texture;
     struct {
         int gen;

demos/09-shadows.c

@@ -90,7 +90,7 @@ int main(int argc, char** argv) {
         if( !initialized ) {
             initialized = 1;
             sky = skybox(flag("--mie") ? 0 : SKY_DIRS[SKY_DIR], 0);
-            sm = shadowmap(512, 2048);
+            sm = shadowmap(512, 4096);
             // sm.blur_pcf = 1;
             // sm.blur_scale 
             mdl = model(OBJ_MDLS[OBJ_MDL], 0);
@@ -113,7 +113,7 @@ int main(int argc, char** argv) {
         };
         static unsigned mode = DIR;
 
-        if (active) {
+        if (!ui_active()) {
             if (input_down(KEY_1)) mode = POINT;
             if (input_down(KEY_2)) mode = SPOT;
             if (input_down(KEY_3)) mode = DIR;

engine/art/shaderlib/light.glsl

@@ -30,6 +30,7 @@ struct light_t {
     float normal_bias;
     float min_variance;
     float variance_transition;
+    float shadow_softness;
 };
 
 const int LIGHT_DIRECTIONAL = 0;

engine/art/shaderlib/shadowmap.glsl

@@ -10,62 +10,85 @@ uniform sampler2D shadowMap2D[MAX_LIGHTS * NUM_SHADOW_CASCADES];
 uniform sampler3D shadow_offsets;
 uniform int shadow_filter_size;
 uniform int shadow_window_size;
-uniform float shadow_offset_radius;
 
 // const float bias_modifier[NUM_SHADOW_CASCADES] = float[NUM_SHADOW_CASCADES](0.95, 0.35, 0.20, 0.1, 0.1, 0.1);
 const float bias_modifier[NUM_SHADOW_CASCADES] = float[NUM_SHADOW_CASCADES](1.0, 6.0, 9.0, 16.0);
 // const float bias_modifier[NUM_SHADOW_CASCADES] = float[NUM_SHADOW_CASCADES](0.95, 0.35, 0.20, 0.15);
 
-//// From http://fabiensanglard.net/shadowmappingVSM/index.php
+vec2 shadow_vsm_variance(vec3 dir, int light_index, float distance, float min_variance, float variance_transition) {
-float shadow_vsm(float distance, vec3 dir, int light_index, float min_variance, float variance_transition) {
+    // Calculate the variance
-    distance = distance/200;
+    vec2 moments = texture(shadowMap[light_index], dir).rg;
-    
-    // Define offsets for 3x3 PCF
-    vec3 offsets[9] = vec3[9](
-        vec3(-1, -1, 0) * 0.01,
-        vec3( 0, -1, 0) * 0.01,
-        vec3( 1, -1, 0) * 0.01,
-        vec3(-1,  0, 0) * 0.01,
-        vec3( 0,  0, 0) * 0.01,
-        vec3( 1,  0, 0) * 0.01,
-        vec3(-1,  1, 0) * 0.01,
-        vec3( 0,  1, 0) * 0.01,
-        vec3( 1,  1, 0) * 0.01
-    );
-    
-    float shadow = 0.0;
-
-    // Perform 3x3 PCF
-    for (int i = 0; i < 9; i++) {
-        vec3 sampleDir = dir + offsets[i] * (rand(vec2(v_position_ws.x + offsets[i].x, v_position_ws.y + offsets[i].y))*1.75f + 1.25f);
-        vec2 moments = texture(shadowMap[light_index], sampleDir).rg;
-
-        // If the shadow map is sampled outside of its bounds, add 1.0
-        if (moments.x == 1.0 && moments.y == 1.0) {
-            shadow += 1.0;
-            continue;
-        }
-        
-        // Surface is fully lit if the current fragment is before the light occluder
-        if (distance <= moments.x) {
-            shadow += 1.0;
-            continue;
-        }
-        
-        // Calculate VSM for this sample
-        float p = step(distance, moments.x);
     float variance = max(moments.y - (moments.x * moments.x), min_variance);
     float d = distance - moments.x;
-        float p_max = linstep(variance_transition, 1.0, variance / (variance + d*d));
+    return vec2(linstep(variance_transition, 1.0, variance / (variance + d * d)), moments.x);
-        
-        shadow += min(max(p, p_max), 1.0);
 }
 
-    // Average the results
+//// From http://fabiensanglard.net/shadowmappingVSM/index.php
-    return shadow / 9.0;
+float shadow_vsm(float distance, vec3 dir, int light_index, float min_variance, float variance_transition, float shadow_softness_raw) {
+    distance = distance / 200;
+    float shadow_softness = shadow_softness_raw * 10.0;
+
+    // Get the offset coordinates
+    ivec3 ofs_coord = ivec3(0);
+    vec2 ofs = mod(gl_FragCoord.xy, vec2(shadow_window_size));
+    ofs_coord.yz = ivec2(ofs);
+    float ofs_sum = 0.0;
+    int samples_div2 = int(shadow_filter_size * shadow_filter_size / 2.0);
+    vec4 sc = vec4(dir, 1.0);
+    sc.z = dir.z;
+
+    vec2 texelSize = 1.0 / textureSize(shadowMap[light_index], 0);
+
+    for (int i = 0; i < 4; i++) {
+        ofs_coord.x = i;
+        vec4 offsets = texelFetch(shadow_offsets, ofs_coord, 0) * shadow_softness;
+        sc.xy = dir.xy + offsets.rg * texelSize;
+        vec2 variance = shadow_vsm_variance(sc.xyz, light_index, distance, min_variance, variance_transition);
+        ofs_sum += min(max(step(distance, variance.y), variance.x), 1.0);
+
+        sc.xy = dir.xy + offsets.ba * texelSize;
+        variance = shadow_vsm_variance(sc.xyz, light_index, distance, min_variance, variance_transition);
+        ofs_sum += min(max(step(distance, variance.y), variance.x), 1.0);
     }
 
-float shadow_csm(float distance, vec3 lightDir, int light_index, float shadow_bias, float normal_bias) {
+    float shadow_sum = ofs_sum / 8.0;
+
+    if (shadow_sum != 0.0 && shadow_sum != 1.0) {
+        for (int i = 4; i < samples_div2; i++) {
+            ofs_coord.x = i;
+            vec4 offsets = texelFetch(shadow_offsets, ofs_coord, 0) * shadow_softness;
+            sc.xy = dir.xy + offsets.rg * texelSize;
+            vec2 variance = shadow_vsm_variance(sc.xyz, light_index, distance, min_variance, variance_transition);
+            ofs_sum += min(max(step(distance, variance.y), variance.x), 1.0);
+
+            sc.xy = dir.xy + offsets.ba * texelSize;
+            variance = shadow_vsm_variance(sc.xyz, light_index, distance, min_variance, variance_transition);
+            ofs_sum += min(max(step(distance, variance.y), variance.x), 1.0);
+        }
+
+        shadow_sum = ofs_sum / (samples_div2 * 2.0);
+    }
+
+    // vec3 sampleDir = dir + (rand(vec2(v_position_ws.x, v_position_ws.y))*0.25f);
+    // float shadow = 0.0;
+    // vec2 moments = ;
+
+    // // Calculate the variance
+    // float variance = max(moments.y - (moments.x * moments.x), min_variance);
+    // float d = distance - moments.x;
+    // float p_max = linstep(variance_transition, 1.0, variance / (variance + d * d));
+
+    return shadow_sum;//min(max(step(distance, moments.x), shadow_sum), 1.0);
+}
+
+float shadowmap_cascade_sample(vec2 sc, int cascade_index, float blend_factor) {
+    float s1 = texture(shadowMap2D[cascade_index], sc).r;
+    // float s2 = texture(shadowMap2D[cascade_index + 1], sc).r;
+    // return mix(s1, s2, blend_factor);
+    return s1;
+}
+
+float shadow_csm(float distance, vec3 lightDir, int light_index, float shadow_bias, float normal_bias, float shadow_softness) {
     // Determine which cascade to use
     int cascade_index = -1;
     int min_cascades_range = light_index * NUM_SHADOW_CASCADES;
@@ -80,9 +103,25 @@ float shadow_csm(float distance, vec3 lightDir, int light_index, float shadow_bi
         cascade_index = max_cascades_range - 1;
     }
     
-    light_t light = u_lights[light_index];
     int matrix_index = cascade_index - min_cascades_range;
 
+    // Blend cascades using a blend region value
+    float blend_region = 200.0;
+    float blend_factor = 0.0;
+    if (matrix_index < NUM_SHADOW_CASCADES - 1) {
+        blend_factor = 0.5;
+    }
+    //     float cascade_start = u_cascade_distances[cascade_index];
+    //     float cascade_end = u_cascade_distances[cascade_index + 1];
+    //     float blend_start = cascade_end - blend_region;
+        
+    //     if (distance > blend_start) {
+    //         blend_factor = smoothstep(blend_start, cascade_end, distance);
+    //     }
+    // }
+
+    light_t light = u_lights[light_index];
+
     vec4 fragPosLightSpace = light.shadow_matrix[matrix_index] * vec4(v_position_ws, 1.0);
 
     // Perform perspective divide
@@ -116,13 +155,13 @@ float shadow_csm(float distance, vec3 lightDir, int light_index, float shadow_bi
 
     for (int i = 0; i < 4; i++) {
         ofs_coord.x = i;
-        vec4 offsets = texelFetch(shadow_offsets, ofs_coord, 0) * shadow_offset_radius;
+        vec4 offsets = texelFetch(shadow_offsets, ofs_coord, 0) * shadow_softness;
         sc.xy = projCoords.xy + offsets.rg * texelSize;
-        float csmDepth = texture(shadowMap2D[cascade_index], sc.xy).r;
+        float csmDepth = shadowmap_cascade_sample(sc.xy, cascade_index, blend_factor);
         ofs_sum += currentDepth - bias > csmDepth ? 1.0 : 0.0;
 
         sc.xy = projCoords.xy + offsets.ba * texelSize;
-        csmDepth = texture(shadowMap2D[cascade_index], sc.xy).r;
+        csmDepth = shadowmap_cascade_sample(sc.xy, cascade_index, blend_factor);
         ofs_sum += currentDepth - bias > csmDepth ? 1.0 : 0.0;
     }
 
@@ -131,13 +170,13 @@ float shadow_csm(float distance, vec3 lightDir, int light_index, float shadow_bi
     if (shadow_sum != 0.0 && shadow_sum != 1.0) {
         for (int i = 4; i < samples_div2; i++) {
             ofs_coord.x = i;
-            vec4 offsets = texelFetch(shadow_offsets, ofs_coord, 0) * shadow_offset_radius;
+            vec4 offsets = texelFetch(shadow_offsets, ofs_coord, 0) * shadow_softness;
             sc.xy = projCoords.xy + offsets.rg * texelSize;
-            float csmDepth = texture(shadowMap2D[cascade_index], sc.xy).r;
+            float csmDepth = shadowmap_cascade_sample(sc.xy, cascade_index, blend_factor);
             ofs_sum += currentDepth - bias > csmDepth ? 1.0 : 0.0;
 
             sc.xy = projCoords.xy + offsets.ba * texelSize;
-            csmDepth = texture(shadowMap2D[cascade_index], sc.xy).r;
+            csmDepth = shadowmap_cascade_sample(sc.xy, cascade_index, blend_factor);
             ofs_sum += currentDepth - bias > csmDepth ? 1.0 : 0.0;
         }
 
@@ -153,12 +192,12 @@ vec4 shadowmap(int idx, in vec4 peye, in vec4 neye) {
 
     if (light.processed_shadows) {
         if (light.type == LIGHT_DIRECTIONAL) {
-            shadowFactor = shadow_csm(-peye.z, light.dir, idx, light.shadow_bias, light.normal_bias);
+            shadowFactor = shadow_csm(-peye.z, light.dir, idx, light.shadow_bias, light.normal_bias, light.shadow_softness);
         } else if (light.type == LIGHT_POINT || light.type == LIGHT_SPOT) {
             vec3 light_pos = (view * vec4(light.pos, 1.0)).xyz;
             vec3 dir = light_pos - fragment;
             vec4 sc = inv_view * vec4(dir, 0.0);
-            shadowFactor = shadow_vsm(length(dir), -sc.xyz, idx, light.min_variance, light.variance_transition);
+            shadowFactor = shadow_vsm(length(dir), -sc.xyz, idx, light.min_variance, light.variance_transition, light.shadow_softness);
         }
     }
 

engine/joint/v4k.h

@@ -17291,6 +17291,7 @@ typedef struct light_t {
     float variance_transition; //< VSM
     float shadow_bias; //< CSM
     float normal_bias; //< CSM
+    float shadow_softness;
 
     // internals
     bool cached; //< used by scene to invalidate cached light data
@@ -17350,7 +17351,6 @@ typedef struct shadowmap_t {
 
     // shadowmap offsets texture;
     int filter_size, window_size;
-    float offset_radius;
     handle offsets_texture;
 
     struct {
@@ -383307,10 +383307,11 @@ light_t light() {
     l.outerCone = 0.9f; // 25 deg
     l.cast_shadows = true;
     l.processed_shadows = false;
-    l.shadow_distance = 200.0f;
+    l.shadow_distance = 400.0f;
     l.shadow_near_clip = 0.01f;
     l.shadow_bias = 0.15f;
     l.normal_bias = 0.05f;
+    l.shadow_softness = 7.0f;
     l.min_variance = 0.00002f;
     l.variance_transition = 0.2f;
     return l;
@@ -383393,6 +383394,7 @@ void light_update(unsigned num_lights, light_t *lv) {
         shader_float(va("u_lights[%d].outerCone", i), lv[i].outerCone);
         shader_float(va("u_lights[%d].shadow_bias", i), lv[i].shadow_bias);
         shader_float(va("u_lights[%d].normal_bias", i), lv[i].normal_bias);
+        shader_float(va("u_lights[%d].shadow_softness", i), lv[i].shadow_softness);
         shader_float(va("u_lights[%d].min_variance", i), lv[i].min_variance);
         shader_float(va("u_lights[%d].variance_transition", i), lv[i].variance_transition);
         shader_bool(va("u_lights[%d].processed_shadows", i), lv[i].processed_shadows);
@@ -383420,6 +383422,7 @@ void ui_light(light_t *l) {
     ui_float("Outer Cone", &l->outerCone);
     ui_float_("Shadow Bias", &l->shadow_bias, 0.00005);
     ui_float_("Normal Bias", &l->normal_bias, 0.00005);
+    ui_float_("Shadow Softness", &l->shadow_softness, 0.5);
     ui_float_("Min Variance", &l->min_variance, 0.00005);
     ui_float_("Variance Transition", &l->variance_transition, 0.0005);
 }
@@ -383468,7 +383471,7 @@ shadowmap_init_caster_vsm(shadowmap_t *s, int light_index, int texture_width) {
         return;
     }
 
-    // Create a cubemap color texture
+    // Create a cubemap moments texture
     glGenTextures(1, &s->maps[light_index].texture);
     glBindTexture(GL_TEXTURE_CUBE_MAP, s->maps[light_index].texture);
     for (int i = 0; i < 6; i++) {
@@ -383526,7 +383529,6 @@ shadowmap_t shadowmap(int vsm_texture_width, int csm_texture_width) { // = 512,
     s.vsm_blur_scale = 0.75f;
     s.filter_size = 8;
     s.window_size = 10;
-    s.offset_radius = 7.0f;
 #if 0
     s.cascade_splits[0] = 0.1f;
     s.cascade_splits[1] = 0.3f;
@@ -384121,7 +384123,6 @@ void ui_shadowmap(shadowmap_t *s) {
     if (ui_collapse("Shadowmap Offsets", "shadowmap_offsets")) {
         ui_int("Filter Size", &s->filter_size);
         ui_int("Window Size", &s->window_size);
-        ui_float("Random Radius", &s->offset_radius);
         ui_collapse_end();
     }
 
@@ -386326,7 +386327,6 @@ void model_set_uniforms(model_t m, int shader, mat44 mv, mat44 proj, mat44 view,
                 glBindTexture(GL_TEXTURE_3D, m.shadow_map->offsets_texture);
                 shader_int("shadow_filter_size", m.shadow_map->filter_size);
                 shader_int("shadow_window_size", m.shadow_map->window_size);
-                shader_float("shadow_offset_radius", m.shadow_map->offset_radius);
             }
         }
         else if (m.shadow_map == NULL || !m.shadow_receiver) {

engine/split/v4k_render.c

@@ -1482,10 +1482,11 @@ light_t light() {
     l.outerCone = 0.9f; // 25 deg
     l.cast_shadows = true;
     l.processed_shadows = false;
-    l.shadow_distance = 200.0f;
+    l.shadow_distance = 400.0f;
     l.shadow_near_clip = 0.01f;
     l.shadow_bias = 0.15f;
     l.normal_bias = 0.05f;
+    l.shadow_softness = 7.0f;
     l.min_variance = 0.00002f;
     l.variance_transition = 0.2f;
     return l;
@@ -1568,6 +1569,7 @@ void light_update(unsigned num_lights, light_t *lv) {
         shader_float(va("u_lights[%d].outerCone", i), lv[i].outerCone);
         shader_float(va("u_lights[%d].shadow_bias", i), lv[i].shadow_bias);
         shader_float(va("u_lights[%d].normal_bias", i), lv[i].normal_bias);
+        shader_float(va("u_lights[%d].shadow_softness", i), lv[i].shadow_softness);
         shader_float(va("u_lights[%d].min_variance", i), lv[i].min_variance);
         shader_float(va("u_lights[%d].variance_transition", i), lv[i].variance_transition);
         shader_bool(va("u_lights[%d].processed_shadows", i), lv[i].processed_shadows);
@@ -1595,6 +1597,7 @@ void ui_light(light_t *l) {
     ui_float("Outer Cone", &l->outerCone);
     ui_float_("Shadow Bias", &l->shadow_bias, 0.00005);
     ui_float_("Normal Bias", &l->normal_bias, 0.00005);
+    ui_float_("Shadow Softness", &l->shadow_softness, 0.5);
     ui_float_("Min Variance", &l->min_variance, 0.00005);
     ui_float_("Variance Transition", &l->variance_transition, 0.0005);
 }
@@ -1643,7 +1646,7 @@ shadowmap_init_caster_vsm(shadowmap_t *s, int light_index, int texture_width) {
         return;
     }
 
-    // Create a cubemap color texture
+    // Create a cubemap moments texture
     glGenTextures(1, &s->maps[light_index].texture);
     glBindTexture(GL_TEXTURE_CUBE_MAP, s->maps[light_index].texture);
     for (int i = 0; i < 6; i++) {
@@ -1701,7 +1704,6 @@ shadowmap_t shadowmap(int vsm_texture_width, int csm_texture_width) { // = 512,
     s.vsm_blur_scale = 0.75f;
     s.filter_size = 8;
     s.window_size = 10;
-    s.offset_radius = 7.0f;
 #if 0
     s.cascade_splits[0] = 0.1f;
     s.cascade_splits[1] = 0.3f;
@@ -2296,7 +2298,6 @@ void ui_shadowmap(shadowmap_t *s) {
     if (ui_collapse("Shadowmap Offsets", "shadowmap_offsets")) {
         ui_int("Filter Size", &s->filter_size);
         ui_int("Window Size", &s->window_size);
-        ui_float("Random Radius", &s->offset_radius);
         ui_collapse_end();
     }
 
@@ -4501,7 +4502,6 @@ void model_set_uniforms(model_t m, int shader, mat44 mv, mat44 proj, mat44 view,
                 glBindTexture(GL_TEXTURE_3D, m.shadow_map->offsets_texture);
                 shader_int("shadow_filter_size", m.shadow_map->filter_size);
                 shader_int("shadow_window_size", m.shadow_map->window_size);
-                shader_float("shadow_offset_radius", m.shadow_map->offset_radius);
             }
         }
         else if (m.shadow_map == NULL || !m.shadow_receiver) {

engine/split/v4k_render.h

@@ -323,6 +323,7 @@ typedef struct light_t {
     float variance_transition; //< VSM
     float shadow_bias; //< CSM
     float normal_bias; //< CSM
+    float shadow_softness;
 
     // internals
     bool cached; //< used by scene to invalidate cached light data
@@ -382,7 +383,6 @@ typedef struct shadowmap_t {
 
     // shadowmap offsets texture;
     int filter_size, window_size;
-    float offset_radius;
     handle offsets_texture;
 
     struct {

engine/v4k.c

@@ -18336,10 +18336,11 @@ light_t light() {
     l.outerCone = 0.9f; // 25 deg
     l.cast_shadows = true;
     l.processed_shadows = false;
-    l.shadow_distance = 200.0f;
+    l.shadow_distance = 400.0f;
     l.shadow_near_clip = 0.01f;
     l.shadow_bias = 0.15f;
     l.normal_bias = 0.05f;
+    l.shadow_softness = 7.0f;
     l.min_variance = 0.00002f;
     l.variance_transition = 0.2f;
     return l;
@@ -18422,6 +18423,7 @@ void light_update(unsigned num_lights, light_t *lv) {
         shader_float(va("u_lights[%d].outerCone", i), lv[i].outerCone);
         shader_float(va("u_lights[%d].shadow_bias", i), lv[i].shadow_bias);
         shader_float(va("u_lights[%d].normal_bias", i), lv[i].normal_bias);
+        shader_float(va("u_lights[%d].shadow_softness", i), lv[i].shadow_softness);
         shader_float(va("u_lights[%d].min_variance", i), lv[i].min_variance);
         shader_float(va("u_lights[%d].variance_transition", i), lv[i].variance_transition);
         shader_bool(va("u_lights[%d].processed_shadows", i), lv[i].processed_shadows);
@@ -18449,6 +18451,7 @@ void ui_light(light_t *l) {
     ui_float("Outer Cone", &l->outerCone);
     ui_float_("Shadow Bias", &l->shadow_bias, 0.00005);
     ui_float_("Normal Bias", &l->normal_bias, 0.00005);
+    ui_float_("Shadow Softness", &l->shadow_softness, 0.5);
     ui_float_("Min Variance", &l->min_variance, 0.00005);
     ui_float_("Variance Transition", &l->variance_transition, 0.0005);
 }
@@ -18497,7 +18500,7 @@ shadowmap_init_caster_vsm(shadowmap_t *s, int light_index, int texture_width) {
         return;
     }
 
-    // Create a cubemap color texture
+    // Create a cubemap moments texture
     glGenTextures(1, &s->maps[light_index].texture);
     glBindTexture(GL_TEXTURE_CUBE_MAP, s->maps[light_index].texture);
     for (int i = 0; i < 6; i++) {
@@ -18555,7 +18558,6 @@ shadowmap_t shadowmap(int vsm_texture_width, int csm_texture_width) { // = 512,
     s.vsm_blur_scale = 0.75f;
     s.filter_size = 8;
     s.window_size = 10;
-    s.offset_radius = 7.0f;
 #if 0
     s.cascade_splits[0] = 0.1f;
     s.cascade_splits[1] = 0.3f;
@@ -19150,7 +19152,6 @@ void ui_shadowmap(shadowmap_t *s) {
     if (ui_collapse("Shadowmap Offsets", "shadowmap_offsets")) {
         ui_int("Filter Size", &s->filter_size);
         ui_int("Window Size", &s->window_size);
-        ui_float("Random Radius", &s->offset_radius);
         ui_collapse_end();
     }
 
@@ -21355,7 +21356,6 @@ void model_set_uniforms(model_t m, int shader, mat44 mv, mat44 proj, mat44 view,
                 glBindTexture(GL_TEXTURE_3D, m.shadow_map->offsets_texture);
                 shader_int("shadow_filter_size", m.shadow_map->filter_size);
                 shader_int("shadow_window_size", m.shadow_map->window_size);
-                shader_float("shadow_offset_radius", m.shadow_map->offset_radius);
             }
         }
         else if (m.shadow_map == NULL || !m.shadow_receiver) {

engine/v4k.h

@@ -3358,6 +3358,7 @@ typedef struct light_t {
     float variance_transition; //< VSM
     float shadow_bias; //< CSM
     float normal_bias; //< CSM
+    float shadow_softness;
 
     // internals
     bool cached; //< used by scene to invalidate cached light data
@@ -3417,7 +3418,6 @@ typedef struct shadowmap_t {
 
     // shadowmap offsets texture;
     int filter_size, window_size;
-    float offset_radius;
     handle offsets_texture;
 
     struct {