From 55d357b1ebcff4560386e72500707304b6bef50b Mon Sep 17 00:00:00 2001 From: reduz Date: Thu, 29 Jul 2021 13:30:39 -0300 Subject: Fix directional shadow bias * Simplified code a lot, bias based on normalized cascade size. * Lets scale cascades, max distance, etc. without creating acne. * Fixed normal biasing in directional shadows. I removed normal biasing in both omni and spot shadows, since the technique can't be easily implemented there. Will need to be replaced by something else. --- .../renderer_rd/renderer_scene_render_rd.cpp | 10 +-- .../shaders/scene_forward_lights_inc.glsl | 25 ++------ servers/rendering/renderer_scene_cull.cpp | 75 ++-------------------- 3 files changed, 12 insertions(+), 98 deletions(-) (limited to 'servers') diff --git a/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp b/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp index 2e0e7c3c43..27d675042f 100644 --- a/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp +++ b/servers/rendering/renderer_rd/renderer_scene_render_rd.cpp @@ -2701,7 +2701,7 @@ void RendererSceneRenderRD::_setup_lights(const PagedArray &p_lights, const CameraMatrix shadow_mtx = rectm * bias * matrix * modelview; light_data.shadow_split_offsets[j] = split; float bias_scale = li->shadow_transform[j].bias_scale; - light_data.shadow_bias[j] = storage->light_get_param(base, RS::LIGHT_PARAM_SHADOW_BIAS) * bias_scale; + light_data.shadow_bias[j] = storage->light_get_param(base, RS::LIGHT_PARAM_SHADOW_BIAS) / 100.0 * bias_scale; light_data.shadow_normal_bias[j] = storage->light_get_param(base, RS::LIGHT_PARAM_SHADOW_NORMAL_BIAS) * li->shadow_transform[j].shadow_texel_size; light_data.shadow_transmittance_bias[j] = storage->light_get_transmittance_bias(base) * bias_scale; light_data.shadow_z_range[j] = li->shadow_transform[j].farplane; @@ -2872,14 +2872,10 @@ void RendererSceneRenderRD::_setup_lights(const PagedArray &p_lights, const light_data.shadow_enabled = true; if (type == RS::LIGHT_SPOT) { - light_data.shadow_bias = (storage->light_get_param(base, RS::LIGHT_PARAM_SHADOW_BIAS) * radius / 10.0); - float shadow_texel_size = Math::tan(Math::deg2rad(spot_angle)) * radius * 2.0; - shadow_texel_size *= light_instance_get_shadow_texel_size(li->self, p_shadow_atlas); - - light_data.shadow_normal_bias = storage->light_get_param(base, RS::LIGHT_PARAM_SHADOW_NORMAL_BIAS) * shadow_texel_size; + light_data.shadow_bias = (storage->light_get_param(base, RS::LIGHT_PARAM_SHADOW_BIAS) / 100.0); } else { //omni - light_data.shadow_bias = storage->light_get_param(base, RS::LIGHT_PARAM_SHADOW_BIAS) * radius / 10.0; + light_data.shadow_bias = storage->light_get_param(base, RS::LIGHT_PARAM_SHADOW_BIAS) / 100.0; float shadow_texel_size = light_instance_get_shadow_texel_size(li->self, p_shadow_atlas); light_data.shadow_normal_bias = storage->light_get_param(base, RS::LIGHT_PARAM_SHADOW_NORMAL_BIAS) * shadow_texel_size * 2.0; // applied in -1 .. 1 space } diff --git a/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl b/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl index 7039ea2942..803a416303 100644 --- a/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl +++ b/servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl @@ -412,14 +412,8 @@ float light_process_omni_shadow(uint idx, vec3 vertex, vec3 normal) { vec4 v = vec4(vertex, 1.0); vec4 splane = (omni_lights.data[idx].shadow_matrix * v); - float shadow_len = length(splane.xyz); //need to remember shadow len from here - { - vec3 nofs = normal_interp * omni_lights.data[idx].shadow_normal_bias / omni_lights.data[idx].inv_radius; - nofs *= (1.0 - max(0.0, dot(normalize(light_rel_vec), normalize(normal_interp)))); - v.xyz += nofs; - splane = (omni_lights.data[idx].shadow_matrix * v); - } + float shadow_len = length(splane.xyz); //need to remember shadow len from here float shadow; @@ -528,7 +522,8 @@ float light_process_omni_shadow(uint idx, vec3 vertex, vec3 normal) { splane.xy /= splane.z; splane.xy = splane.xy * 0.5 + 0.5; - splane.z = (shadow_len - omni_lights.data[idx].shadow_bias) * omni_lights.data[idx].inv_radius; + splane.z = shadow_len * omni_lights.data[idx].inv_radius; + splane.z -= omni_lights.data[idx].shadow_bias; splane.xy = clamp_rect.xy + splane.xy * clamp_rect.zw; splane.w = 1.0; //needed? i think it should be 1 already shadow = sample_pcf_shadow(shadow_atlas, omni_lights.data[idx].soft_shadow_scale * scene_data.shadow_atlas_pixel_size, splane); @@ -704,27 +699,17 @@ float light_process_spot_shadow(uint idx, vec3 vertex, vec3 normal) { //there is a shadowmap vec4 v = vec4(vertex, 1.0); - v.xyz -= spot_dir * spot_lights.data[idx].shadow_bias; - - float z_norm = dot(spot_dir, -light_rel_vec) * spot_lights.data[idx].inv_radius; - - float depth_bias_scale = 1.0 / (max(0.0001, z_norm)); //the closer to the light origin, the more you have to offset to reach 1px in the map - vec3 normal_bias = normalize(normal_interp) * (1.0 - max(0.0, dot(spot_dir, -normalize(normal_interp)))) * spot_lights.data[idx].shadow_normal_bias * depth_bias_scale; - normal_bias -= spot_dir * dot(spot_dir, normal_bias); //only XY, no Z - v.xyz += normal_bias; - - //adjust with bias - z_norm = dot(spot_dir, v.xyz - spot_lights.data[idx].position) * spot_lights.data[idx].inv_radius; - float shadow; vec4 splane = (spot_lights.data[idx].shadow_matrix * v); splane /= splane.w; + splane.z -= spot_lights.data[idx].shadow_bias; if (sc_use_light_soft_shadows && spot_lights.data[idx].soft_shadow_size > 0.0) { //soft shadow //find blocker + float z_norm = dot(spot_dir, -light_rel_vec) * spot_lights.data[idx].inv_radius; vec2 shadow_uv = splane.xy * spot_lights.data[idx].atlas_rect.zw + spot_lights.data[idx].atlas_rect.xy; diff --git a/servers/rendering/renderer_scene_cull.cpp b/servers/rendering/renderer_scene_cull.cpp index 83d1b33bf2..210220e318 100644 --- a/servers/rendering/renderer_scene_cull.cpp +++ b/servers/rendering/renderer_scene_cull.cpp @@ -1955,10 +1955,6 @@ void RendererSceneCull::_light_instance_setup_directional_shadow(int p_shadow_in bool overlap = RSG::storage->light_directional_get_blend_splits(p_instance->base); - real_t first_radius = 0.0; - - real_t min_distance_bias_scale = distances[1]; - cull.shadow_count = p_shadow_index + 1; cull.shadows[p_shadow_index].cascade_count = splits; cull.shadows[p_shadow_index].light_instance = light->instance; @@ -2006,8 +2002,8 @@ void RendererSceneCull::_light_instance_setup_directional_shadow(int p_shadow_in real_t z_min_cam = 0.f; //real_t z_max_cam = 0.f; - real_t bias_scale = 1.0; - real_t aspect_bias_scale = 1.0; + //real_t bias_scale = 1.0; + //real_t aspect_bias_scale = 1.0; //used for culling @@ -2061,12 +2057,6 @@ void RendererSceneCull::_light_instance_setup_directional_shadow(int p_shadow_in radius *= texture_size / (texture_size - 2.0); //add a texel by each side - if (i == 0) { - first_radius = radius; - } else { - bias_scale = radius / first_radius; - } - z_min_cam = z_vec.dot(center) - radius; { @@ -2110,64 +2100,7 @@ void RendererSceneCull::_light_instance_setup_directional_shadow(int p_shadow_in // a pre pass will need to be needed to determine the actual z-near to be used - if (pancake_size > 0) { - z_max = z_vec.dot(center) + radius + pancake_size; - } - - if (aspect != 1.0) { - // if the aspect is different, then the radius will become larger. - // if this happens, then bias needs to be adjusted too, as depth will increase - // to do this, compare the depth of one that would have resulted from a square frustum - - CameraMatrix camera_matrix_square; - if (p_cam_orthogonal) { - Vector2 vp_he = camera_matrix.get_viewport_half_extents(); - if (p_cam_vaspect) { - camera_matrix_square.set_orthogonal(vp_he.x * 2.0, 1.0, distances[(i == 0 || !overlap) ? i : i - 1], distances[i + 1], true); - } else { - camera_matrix_square.set_orthogonal(vp_he.y * 2.0, 1.0, distances[(i == 0 || !overlap) ? i : i - 1], distances[i + 1], false); - } - } else { - Vector2 vp_he = camera_matrix.get_viewport_half_extents(); - if (p_cam_vaspect) { - camera_matrix_square.set_frustum(vp_he.x * 2.0, 1.0, Vector2(), distances[(i == 0 || !overlap) ? i : i - 1], distances[i + 1], true); - } else { - camera_matrix_square.set_frustum(vp_he.y * 2.0, 1.0, Vector2(), distances[(i == 0 || !overlap) ? i : i - 1], distances[i + 1], false); - } - } - - Vector3 endpoints_square[8]; // frustum plane endpoints - res = camera_matrix_square.get_endpoints(p_cam_transform, endpoints_square); - ERR_CONTINUE(!res); - Vector3 center_square; - - for (int j = 0; j < 8; j++) { - center_square += endpoints_square[j]; - } - - center_square /= 8.0; - - real_t radius_square = 0; - - for (int j = 0; j < 8; j++) { - real_t d = center_square.distance_to(endpoints_square[j]); - if (d > radius_square) { - radius_square = d; - } - } - - radius_square *= texture_size / (texture_size - 2.0); //add a texel by each side - - float z_max_square = z_vec.dot(center_square) + radius_square + pancake_size; - - real_t z_min_cam_square = z_vec.dot(center_square) - radius_square; - - aspect_bias_scale = (z_max - z_min_cam) / (z_max_square - z_min_cam_square); - - // this is not entirely perfect, because the cull-adjusted z-max may be different - // but at least it's warranted that it results in a greater bias, so no acne should be present either way. - // pancaking also helps with this. - } + z_max = z_vec.dot(center) + radius + pancake_size; { CameraMatrix ortho_camera; @@ -2188,7 +2121,7 @@ void RendererSceneCull::_light_instance_setup_directional_shadow(int p_shadow_in cull.shadows[p_shadow_index].cascades[i].zfar = z_max - z_min_cam; cull.shadows[p_shadow_index].cascades[i].split = distances[i + 1]; cull.shadows[p_shadow_index].cascades[i].shadow_texel_size = radius * 2.0 / texture_size; - cull.shadows[p_shadow_index].cascades[i].bias_scale = bias_scale * aspect_bias_scale * min_distance_bias_scale; + cull.shadows[p_shadow_index].cascades[i].bias_scale = (z_max - z_min_cam); cull.shadows[p_shadow_index].cascades[i].range_begin = z_max; cull.shadows[p_shadow_index].cascades[i].uv_scale = uv_scale; } -- cgit v1.2.3