diff options
Diffstat (limited to 'drivers/gles3/rasterizer_scene_gles3.cpp')
| -rw-r--r-- | drivers/gles3/rasterizer_scene_gles3.cpp | 137 |
1 files changed, 94 insertions, 43 deletions
diff --git a/drivers/gles3/rasterizer_scene_gles3.cpp b/drivers/gles3/rasterizer_scene_gles3.cpp index 89f6b07405..8e86141e77 100644 --- a/drivers/gles3/rasterizer_scene_gles3.cpp +++ b/drivers/gles3/rasterizer_scene_gles3.cpp @@ -497,8 +497,7 @@ void RasterizerSceneGLES3::_update_dirty_skys() { while (sky) { if (sky->radiance == 0) { - sky->mipmap_count = Image::get_image_required_mipmaps(sky->radiance_size, sky->radiance_size, Image::FORMAT_RGBA8) + 1; - + sky->mipmap_count = Image::get_image_required_mipmaps(sky->radiance_size, sky->radiance_size, Image::FORMAT_RGBA8) - 2; // Left uninitialized, will attach a texture at render time glGenFramebuffers(1, &sky->radiance_framebuffer); @@ -837,7 +836,7 @@ void RasterizerSceneGLES3::_update_sky_radiance(Environment *p_env, const Projec int max_processing_layer = sky->mipmap_count; // Update radiance cubemap - if (sky->reflection_dirty && (sky->processing_layer >= max_processing_layer || update_single_frame)) { + if (sky->reflection_dirty && (sky->processing_layer > max_processing_layer || update_single_frame)) { static const Vector3 view_normals[6] = { Vector3(+1, 0, 0), Vector3(-1, 0, 0), @@ -881,7 +880,7 @@ void RasterizerSceneGLES3::_update_sky_radiance(Environment *p_env, const Projec } if (update_single_frame) { - for (int i = 0; i < max_processing_layer; i++) { + for (int i = 0; i <= max_processing_layer; i++) { _filter_sky_radiance(sky, i); } } else { @@ -891,13 +890,52 @@ void RasterizerSceneGLES3::_update_sky_radiance(Environment *p_env, const Projec sky->reflection_dirty = false; } else { - if (sky_mode == RS::SKY_MODE_INCREMENTAL && sky->processing_layer < max_processing_layer) { + if (sky_mode == RS::SKY_MODE_INCREMENTAL && sky->processing_layer <= max_processing_layer) { _filter_sky_radiance(sky, sky->processing_layer); sky->processing_layer++; } } } +// Helper functions for IBL filtering + +Vector3 importance_sample_GGX(Vector2 xi, float roughness4) { + // Compute distribution direction + float phi = 2.0 * Math_PI * xi.x; + float cos_theta = sqrt((1.0 - xi.y) / (1.0 + (roughness4 - 1.0) * xi.y)); + float sin_theta = sqrt(1.0 - cos_theta * cos_theta); + + // Convert to spherical direction + Vector3 half_vector; + half_vector.x = sin_theta * cos(phi); + half_vector.y = sin_theta * sin(phi); + half_vector.z = cos_theta; + + return half_vector; +} + +float distribution_GGX(float NdotH, float roughness4) { + float NdotH2 = NdotH * NdotH; + float denom = (NdotH2 * (roughness4 - 1.0) + 1.0); + denom = Math_PI * denom * denom; + + return roughness4 / denom; +} + +float radical_inverse_vdC(uint32_t bits) { + bits = (bits << 16) | (bits >> 16); + bits = ((bits & 0x55555555) << 1) | ((bits & 0xAAAAAAAA) >> 1); + bits = ((bits & 0x33333333) << 2) | ((bits & 0xCCCCCCCC) >> 2); + bits = ((bits & 0x0F0F0F0F) << 4) | ((bits & 0xF0F0F0F0) >> 4); + bits = ((bits & 0x00FF00FF) << 8) | ((bits & 0xFF00FF00) >> 8); + + return float(bits) * 2.3283064365386963e-10; +} + +Vector2 hammersley(uint32_t i, uint32_t N) { + return Vector2(float(i) / float(N), radical_inverse_vdC(i)); +} + void RasterizerSceneGLES3::_filter_sky_radiance(Sky *p_sky, int p_base_layer) { GLES3::MaterialStorage *material_storage = GLES3::MaterialStorage::get_singleton(); @@ -909,21 +947,60 @@ void RasterizerSceneGLES3::_filter_sky_radiance(Sky *p_sky, int p_base_layer) { if (p_base_layer == 0) { glGenerateMipmap(GL_TEXTURE_CUBE_MAP); + // Copy over base layer without filtering. mode = CubemapFilterShaderGLES3::MODE_COPY; - - //Copy over base layer } - glActiveTexture(GL_TEXTURE1); - glBindTexture(GL_TEXTURE_2D, sky_globals.radical_inverse_vdc_cache_tex); int size = p_sky->radiance_size >> p_base_layer; glViewport(0, 0, size, size); glBindVertexArray(sky_globals.screen_triangle_array); material_storage->shaders.cubemap_filter_shader.version_bind_shader(scene_globals.cubemap_filter_shader_version, mode); - material_storage->shaders.cubemap_filter_shader.version_set_uniform(CubemapFilterShaderGLES3::SAMPLE_COUNT, sky_globals.ggx_samples, scene_globals.cubemap_filter_shader_version, mode); - material_storage->shaders.cubemap_filter_shader.version_set_uniform(CubemapFilterShaderGLES3::ROUGHNESS, float(p_base_layer) / (p_sky->mipmap_count - 1.0), scene_globals.cubemap_filter_shader_version, mode); - material_storage->shaders.cubemap_filter_shader.version_set_uniform(CubemapFilterShaderGLES3::FACE_SIZE, float(size), scene_globals.cubemap_filter_shader_version, mode); + + if (p_base_layer > 0) { + const uint32_t sample_counts[4] = { 1, sky_globals.ggx_samples / 4, sky_globals.ggx_samples / 2, sky_globals.ggx_samples }; + uint32_t sample_count = sample_counts[MIN(3, p_base_layer)]; + + float roughness = float(p_base_layer) / (p_sky->mipmap_count); + float roughness4 = roughness * roughness; + roughness4 *= roughness4; + + float solid_angle_texel = 4.0 * Math_PI / float(6 * size * size); + + LocalVector<float> sample_directions; + sample_directions.resize(4 * sample_count); + + uint32_t index = 0; + float weight = 0.0; + for (uint32_t i = 0; i < sample_count; i++) { + Vector2 xi = hammersley(i, sample_count); + Vector3 dir = importance_sample_GGX(xi, roughness4); + Vector3 light_vec = (2.0 * dir.z * dir - Vector3(0.0, 0.0, 1.0)); + + if (light_vec.z < 0.0) { + continue; + } + + sample_directions[index * 4] = light_vec.x; + sample_directions[index * 4 + 1] = light_vec.y; + sample_directions[index * 4 + 2] = light_vec.z; + + float D = distribution_GGX(dir.z, roughness4); + float pdf = D * dir.z / (4.0 * dir.z) + 0.0001; + + float solid_angle_sample = 1.0 / (float(sample_count) * pdf + 0.0001); + + float mip_level = MAX(0.5 * log2(solid_angle_sample / solid_angle_texel) + float(MAX(1, p_base_layer - 3)), 1.0); + + sample_directions[index * 4 + 3] = mip_level; + weight += light_vec.z; + index++; + } + + glUniform4fv(material_storage->shaders.cubemap_filter_shader.version_get_uniform(CubemapFilterShaderGLES3::SAMPLE_DIRECTIONS_MIP, scene_globals.cubemap_filter_shader_version, mode), sample_count, sample_directions.ptr()); + material_storage->shaders.cubemap_filter_shader.version_set_uniform(CubemapFilterShaderGLES3::WEIGHT, weight, scene_globals.cubemap_filter_shader_version, mode); + material_storage->shaders.cubemap_filter_shader.version_set_uniform(CubemapFilterShaderGLES3::SAMPLE_COUNT, index, scene_globals.cubemap_filter_shader_version, mode); + } for (int i = 0; i < 6; i++) { glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, p_sky->radiance, p_base_layer); @@ -2596,8 +2673,12 @@ void fragment() { material_storage->shaders.sky_shader.initialize(global_defines); sky_globals.shader_default_version = material_storage->shaders.sky_shader.version_create(); material_storage->shaders.sky_shader.version_bind_shader(sky_globals.shader_default_version, SkyShaderGLES3::MODE_BACKGROUND); + } - material_storage->shaders.cubemap_filter_shader.initialize(); + { + String global_defines; + global_defines += "\n#define MAX_SAMPLE_COUNT " + itos(sky_globals.ggx_samples) + "\n"; + material_storage->shaders.cubemap_filter_shader.initialize(global_defines); scene_globals.cubemap_filter_shader_version = material_storage->shaders.cubemap_filter_shader.version_create(); material_storage->shaders.cubemap_filter_shader.version_bind_shader(scene_globals.cubemap_filter_shader_version, CubemapFilterShaderGLES3::MODE_DEFAULT); } @@ -2667,36 +2748,6 @@ void sky() { glBindBuffer(GL_ARRAY_BUFFER, 0); //unbind } - // Radical inverse vdc cache texture used for cubemap filtering. - { - glGenTextures(1, &sky_globals.radical_inverse_vdc_cache_tex); - - glActiveTexture(GL_TEXTURE0); - glBindTexture(GL_TEXTURE_2D, sky_globals.radical_inverse_vdc_cache_tex); - - uint8_t radical_inverse[512]; - - for (uint32_t i = 0; i < 512; i++) { - uint32_t bits = i; - - bits = (bits << 16) | (bits >> 16); - bits = ((bits & 0x55555555) << 1) | ((bits & 0xAAAAAAAA) >> 1); - bits = ((bits & 0x33333333) << 2) | ((bits & 0xCCCCCCCC) >> 2); - bits = ((bits & 0x0F0F0F0F) << 4) | ((bits & 0xF0F0F0F0) >> 4); - bits = ((bits & 0x00FF00FF) << 8) | ((bits & 0xFF00FF00) >> 8); - - float value = float(bits) * 2.3283064365386963e-10; - radical_inverse[i] = uint8_t(CLAMP(value * 255.0, 0, 255)); - } - - glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, 512, 1, 0, GL_RED, GL_UNSIGNED_BYTE, radical_inverse); - glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); - glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); - glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); - glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); //need this for proper sampling - - glBindTexture(GL_TEXTURE_2D, 0); - } #ifdef GLES_OVER_GL glEnable(_EXT_TEXTURE_CUBE_MAP_SEAMLESS); #endif |