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/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "render/background.h"
#include "render/camera.h"
#include "device/device.h"
#include "render/graph.h"
#include "render/integrator.h"
#include "render/light.h"
#include "render/mesh.h"
#include "render/nodes.h"
#include "render/object.h"
#include "render/osl.h"
#include "render/scene.h"
#include "render/shader.h"
#include "render/svm.h"
#include "render/tables.h"
#include "util/util_foreach.h"
CCL_NAMESPACE_BEGIN
thread_mutex ShaderManager::lookup_table_mutex;
vector<float> ShaderManager::beckmann_table;
bool ShaderManager::beckmann_table_ready = false;
/* Beckmann sampling precomputed table, see bsdf_microfacet.h */
/* 2D slope distribution (alpha = 1.0) */
static float beckmann_table_P22(const float slope_x, const float slope_y)
{
return expf(-(slope_x*slope_x + slope_y*slope_y));
}
/* maximal slope amplitude (range that contains 99.99% of the distribution) */
static float beckmann_table_slope_max()
{
return 6.0;
}
/* MSVC 2015 needs this ugly hack to prevent a codegen bug on x86
* see T50176 for details
*/
#if defined(_MSC_VER) && (_MSC_VER == 1900)
# define MSVC_VOLATILE volatile
#else
# define MSVC_VOLATILE
#endif
/* Paper used: Importance Sampling Microfacet-Based BSDFs with the
* Distribution of Visible Normals. Supplemental Material 2/2.
*
* http://hal.inria.fr/docs/01/00/66/20/ANNEX/supplemental2.pdf
*/
static void beckmann_table_rows(float *table, int row_from, int row_to)
{
/* allocate temporary data */
const int DATA_TMP_SIZE = 512;
vector<double> slope_x(DATA_TMP_SIZE);
vector<double> CDF_P22_omega_i(DATA_TMP_SIZE);
/* loop over incident directions */
for(int index_theta = row_from; index_theta < row_to; index_theta++) {
/* incident vector */
const float cos_theta = index_theta / (BECKMANN_TABLE_SIZE - 1.0f);
const float sin_theta = safe_sqrtf(1.0f - cos_theta*cos_theta);
/* for a given incident vector
* integrate P22_{omega_i}(x_slope, 1, 1), Eq. (10) */
slope_x[0] = (double)-beckmann_table_slope_max();
CDF_P22_omega_i[0] = 0;
for(MSVC_VOLATILE int index_slope_x = 1; index_slope_x < DATA_TMP_SIZE; ++index_slope_x) {
/* slope_x */
slope_x[index_slope_x] = (double)(-beckmann_table_slope_max() + 2.0f * beckmann_table_slope_max() * index_slope_x/(DATA_TMP_SIZE - 1.0f));
/* dot product with incident vector */
float dot_product = fmaxf(0.0f, -(float)slope_x[index_slope_x]*sin_theta + cos_theta);
/* marginalize P22_{omega_i}(x_slope, 1, 1), Eq. (10) */
float P22_omega_i = 0.0f;
for(int j = 0; j < 100; ++j) {
float slope_y = -beckmann_table_slope_max() + 2.0f * beckmann_table_slope_max() * j * (1.0f/99.0f);
P22_omega_i += dot_product * beckmann_table_P22((float)slope_x[index_slope_x], slope_y);
}
/* CDF of P22_{omega_i}(x_slope, 1, 1), Eq. (10) */
CDF_P22_omega_i[index_slope_x] = CDF_P22_omega_i[index_slope_x - 1] + (double)P22_omega_i;
}
/* renormalize CDF_P22_omega_i */
for(int index_slope_x = 1; index_slope_x < DATA_TMP_SIZE; ++index_slope_x)
CDF_P22_omega_i[index_slope_x] /= CDF_P22_omega_i[DATA_TMP_SIZE - 1];
/* loop over random number U1 */
int index_slope_x = 0;
for(int index_U = 0; index_U < BECKMANN_TABLE_SIZE; ++index_U) {
const double U = 0.0000001 + 0.9999998 * index_U / (double)(BECKMANN_TABLE_SIZE - 1);
/* inverse CDF_P22_omega_i, solve Eq.(11) */
while(CDF_P22_omega_i[index_slope_x] <= U)
++index_slope_x;
const double interp =
(CDF_P22_omega_i[index_slope_x] - U) /
(CDF_P22_omega_i[index_slope_x] - CDF_P22_omega_i[index_slope_x - 1]);
/* store value */
table[index_U + index_theta*BECKMANN_TABLE_SIZE] = (float)(
interp * slope_x[index_slope_x - 1] +
(1.0 - interp) * slope_x[index_slope_x]);
}
}
}
#undef MSVC_VOLATILE
static void beckmann_table_build(vector<float>& table)
{
table.resize(BECKMANN_TABLE_SIZE*BECKMANN_TABLE_SIZE);
/* multithreaded build */
TaskPool pool;
for(int i = 0; i < BECKMANN_TABLE_SIZE; i+=8)
pool.push(function_bind(&beckmann_table_rows, &table[0], i, i+8));
pool.wait_work();
}
/* Shader */
NODE_DEFINE(Shader)
{
NodeType* type = NodeType::add("shader", create);
SOCKET_BOOLEAN(use_mis, "Use MIS", true);
SOCKET_BOOLEAN(use_transparent_shadow, "Use Transparent Shadow", true);
SOCKET_BOOLEAN(heterogeneous_volume, "Heterogeneous Volume", true);
static NodeEnum volume_sampling_method_enum;
volume_sampling_method_enum.insert("distance", VOLUME_SAMPLING_DISTANCE);
volume_sampling_method_enum.insert("equiangular", VOLUME_SAMPLING_EQUIANGULAR);
volume_sampling_method_enum.insert("multiple_importance", VOLUME_SAMPLING_MULTIPLE_IMPORTANCE);
SOCKET_ENUM(volume_sampling_method, "Volume Sampling Method", volume_sampling_method_enum, VOLUME_SAMPLING_DISTANCE);
static NodeEnum volume_interpolation_method_enum;
volume_interpolation_method_enum.insert("linear", VOLUME_INTERPOLATION_LINEAR);
volume_interpolation_method_enum.insert("cubic", VOLUME_INTERPOLATION_CUBIC);
SOCKET_ENUM(volume_interpolation_method, "Volume Interpolation Method", volume_interpolation_method_enum, VOLUME_INTERPOLATION_LINEAR);
static NodeEnum displacement_method_enum;
displacement_method_enum.insert("bump", DISPLACE_BUMP);
displacement_method_enum.insert("true", DISPLACE_TRUE);
displacement_method_enum.insert("both", DISPLACE_BOTH);
SOCKET_ENUM(displacement_method, "Displacement Method", displacement_method_enum, DISPLACE_BUMP);
return type;
}
Shader::Shader()
: Node(node_type)
{
pass_id = 0;
graph = NULL;
has_surface = false;
has_surface_transparent = false;
has_surface_emission = false;
has_surface_bssrdf = false;
has_volume = false;
has_displacement = false;
has_bump = false;
has_bssrdf_bump = false;
has_surface_spatial_varying = false;
has_volume_spatial_varying = false;
has_object_dependency = false;
has_integrator_dependency = false;
has_volume_connected = false;
displacement_method = DISPLACE_BUMP;
id = -1;
used = false;
need_update = true;
need_update_mesh = true;
}
Shader::~Shader()
{
delete graph;
}
bool Shader::is_constant_emission(float3 *emission)
{
ShaderInput *surf = graph->output()->input("Surface");
if(!surf->link || surf->link->parent->type != EmissionNode::node_type) {
return false;
}
EmissionNode *node = (EmissionNode*) surf->link->parent;
assert(node->input("Color"));
assert(node->input("Strength"));
if(node->input("Color")->link || node->input("Strength")->link) {
return false;
}
*emission = node->color*node->strength;
return true;
}
void Shader::set_graph(ShaderGraph *graph_)
{
/* do this here already so that we can detect if mesh or object attributes
* are needed, since the node attribute callbacks check if their sockets
* are connected but proxy nodes should not count */
if(graph_) {
graph_->remove_proxy_nodes();
if(displacement_method != DISPLACE_BUMP) {
graph_->compute_displacement_hash();
}
}
/* update geometry if displacement changed */
if(displacement_method != DISPLACE_BUMP) {
const char *old_hash = (graph)? graph->displacement_hash.c_str() : "";
const char *new_hash = (graph_)? graph_->displacement_hash.c_str() : "";
if(strcmp(old_hash, new_hash) != 0) {
need_update_mesh = true;
}
}
/* assign graph */
delete graph;
graph = graph_;
/* Store info here before graph optimization to make sure that
* nodes that get optimized away still count. */
has_volume_connected = (graph->output()->input("Volume")->link != NULL);
}
void Shader::tag_update(Scene *scene)
{
/* update tag */
need_update = true;
scene->shader_manager->need_update = true;
/* if the shader previously was emissive, update light distribution,
* if the new shader is emissive, a light manager update tag will be
* done in the shader manager device update. */
if(use_mis && has_surface_emission)
scene->light_manager->need_update = true;
/* Special handle of background MIS light for now: for some reason it
* has use_mis set to false. We are quite close to release now, so
* better to be safe.
*/
if(this == scene->default_background &&
scene->light_manager->has_background_light(scene))
{
scene->light_manager->need_update = true;
}
/* quick detection of which kind of shaders we have to avoid loading
* e.g. surface attributes when there is only a volume shader. this could
* be more fine grained but it's better than nothing */
OutputNode *output = graph->output();
bool prev_has_volume = has_volume;
has_surface = has_surface || output->input("Surface")->link;
has_volume = has_volume || output->input("Volume")->link;
has_displacement = has_displacement || output->input("Displacement")->link;
/* get requested attributes. this could be optimized by pruning unused
* nodes here already, but that's the job of the shader manager currently,
* and may not be so great for interactive rendering where you temporarily
* disconnect a node */
AttributeRequestSet prev_attributes = attributes;
attributes.clear();
foreach(ShaderNode *node, graph->nodes)
node->attributes(this, &attributes);
if(has_displacement && displacement_method == DISPLACE_BOTH) {
attributes.add(ATTR_STD_POSITION_UNDISPLACED);
}
/* compare if the attributes changed, mesh manager will check
* need_update_mesh, update the relevant meshes and clear it. */
if(attributes.modified(prev_attributes)) {
need_update_mesh = true;
scene->mesh_manager->need_update = true;
}
if(has_volume != prev_has_volume) {
scene->mesh_manager->need_flags_update = true;
scene->object_manager->need_flags_update = true;
}
}
void Shader::tag_used(Scene *scene)
{
/* if an unused shader suddenly gets used somewhere, it needs to be
* recompiled because it was skipped for compilation before */
if(!used) {
need_update = true;
scene->shader_manager->need_update = true;
}
}
/* Shader Manager */
ShaderManager::ShaderManager()
{
need_update = true;
beckmann_table_offset = TABLE_OFFSET_INVALID;
}
ShaderManager::~ShaderManager()
{
}
ShaderManager *ShaderManager::create(Scene *scene, int shadingsystem)
{
ShaderManager *manager;
(void)shadingsystem; /* Ignored when built without OSL. */
#ifdef WITH_OSL
if(shadingsystem == SHADINGSYSTEM_OSL) {
manager = new OSLShaderManager();
}
else
#endif
{
manager = new SVMShaderManager();
}
add_default(scene);
return manager;
}
uint ShaderManager::get_attribute_id(ustring name)
{
thread_scoped_spin_lock lock(attribute_lock_);
/* get a unique id for each name, for SVM attribute lookup */
AttributeIDMap::iterator it = unique_attribute_id.find(name);
if(it != unique_attribute_id.end())
return it->second;
uint id = (uint)ATTR_STD_NUM + unique_attribute_id.size();
unique_attribute_id[name] = id;
return id;
}
uint ShaderManager::get_attribute_id(AttributeStandard std)
{
return (uint)std;
}
int ShaderManager::get_shader_id(Shader *shader, bool smooth)
{
/* get a shader id to pass to the kernel */
int id = shader->id;
/* smooth flag */
if(smooth)
id |= SHADER_SMOOTH_NORMAL;
/* default flags */
id |= SHADER_CAST_SHADOW|SHADER_AREA_LIGHT;
return id;
}
void ShaderManager::device_update_shaders_used(Scene *scene)
{
/* figure out which shaders are in use, so SVM/OSL can skip compiling them
* for speed and avoid loading image textures into memory */
uint id = 0;
foreach(Shader *shader, scene->shaders) {
shader->used = false;
shader->id = id++;
}
scene->default_surface->used = true;
scene->default_light->used = true;
scene->default_background->used = true;
scene->default_empty->used = true;
if(scene->background->shader)
scene->background->shader->used = true;
foreach(Mesh *mesh, scene->meshes)
foreach(Shader *shader, mesh->used_shaders)
shader->used = true;
foreach(Light *light, scene->lights)
if(light->shader)
light->shader->used = true;
}
void ShaderManager::device_update_common(Device *device,
DeviceScene *dscene,
Scene *scene,
Progress& /*progress*/)
{
dscene->shader_flag.free();
if(scene->shaders.size() == 0)
return;
uint shader_flag_size = scene->shaders.size()*SHADER_SIZE;
uint *shader_flag = dscene->shader_flag.alloc(shader_flag_size);
uint i = 0;
bool has_volumes = false;
bool has_transparent_shadow = false;
foreach(Shader *shader, scene->shaders) {
uint flag = 0;
if(shader->use_mis)
flag |= SD_USE_MIS;
if(shader->has_surface_transparent && shader->use_transparent_shadow)
flag |= SD_HAS_TRANSPARENT_SHADOW;
if(shader->has_volume) {
flag |= SD_HAS_VOLUME;
has_volumes = true;
/* todo: this could check more fine grained, to skip useless volumes
* enclosed inside an opaque bsdf.
*/
flag |= SD_HAS_TRANSPARENT_SHADOW;
}
/* in this case we can assume transparent surface */
if(shader->has_volume_connected && !shader->has_surface)
flag |= SD_HAS_ONLY_VOLUME;
if(shader->heterogeneous_volume && shader->has_volume_spatial_varying)
flag |= SD_HETEROGENEOUS_VOLUME;
if(shader->has_bssrdf_bump)
flag |= SD_HAS_BSSRDF_BUMP;
if(device->info.has_volume_decoupled) {
if(shader->volume_sampling_method == VOLUME_SAMPLING_EQUIANGULAR)
flag |= SD_VOLUME_EQUIANGULAR;
if(shader->volume_sampling_method == VOLUME_SAMPLING_MULTIPLE_IMPORTANCE)
flag |= SD_VOLUME_MIS;
}
if(shader->volume_interpolation_method == VOLUME_INTERPOLATION_CUBIC)
flag |= SD_VOLUME_CUBIC;
if(shader->has_bump)
flag |= SD_HAS_BUMP;
if(shader->displacement_method != DISPLACE_BUMP)
flag |= SD_HAS_DISPLACEMENT;
/* constant emission check */
float3 constant_emission = make_float3(0.0f, 0.0f, 0.0f);
if(shader->is_constant_emission(&constant_emission))
flag |= SD_HAS_CONSTANT_EMISSION;
/* regular shader */
shader_flag[i++] = flag;
shader_flag[i++] = shader->pass_id;
shader_flag[i++] = __float_as_int(constant_emission.x);
shader_flag[i++] = __float_as_int(constant_emission.y);
shader_flag[i++] = __float_as_int(constant_emission.z);
has_transparent_shadow |= (flag & SD_HAS_TRANSPARENT_SHADOW) != 0;
}
dscene->shader_flag.copy_to_device();
/* lookup tables */
KernelTables *ktables = &dscene->data.tables;
/* beckmann lookup table */
if(beckmann_table_offset == TABLE_OFFSET_INVALID) {
if(!beckmann_table_ready) {
thread_scoped_lock lock(lookup_table_mutex);
if(!beckmann_table_ready) {
beckmann_table_build(beckmann_table);
beckmann_table_ready = true;
}
}
beckmann_table_offset = scene->lookup_tables->add_table(dscene, beckmann_table);
}
ktables->beckmann_offset = (int)beckmann_table_offset;
/* integrator */
KernelIntegrator *kintegrator = &dscene->data.integrator;
kintegrator->use_volumes = has_volumes;
/* TODO(sergey): De-duplicate with flags set in integrator.cpp. */
kintegrator->transparent_shadows = has_transparent_shadow;
}
void ShaderManager::device_free_common(Device *, DeviceScene *dscene, Scene *scene)
{
scene->lookup_tables->remove_table(&beckmann_table_offset);
dscene->shader_flag.free();
}
void ShaderManager::add_default(Scene *scene)
{
/* default surface */
{
ShaderGraph *graph = new ShaderGraph();
DiffuseBsdfNode *diffuse = new DiffuseBsdfNode();
diffuse->color = make_float3(0.8f, 0.8f, 0.8f);
graph->add(diffuse);
graph->connect(diffuse->output("BSDF"), graph->output()->input("Surface"));
Shader *shader = new Shader();
shader->name = "default_surface";
shader->graph = graph;
scene->shaders.push_back(shader);
scene->default_surface = shader;
}
/* default light */
{
ShaderGraph *graph = new ShaderGraph();
EmissionNode *emission = new EmissionNode();
emission->color = make_float3(0.8f, 0.8f, 0.8f);
emission->strength = 0.0f;
graph->add(emission);
graph->connect(emission->output("Emission"), graph->output()->input("Surface"));
Shader *shader = new Shader();
shader->name = "default_light";
shader->graph = graph;
scene->shaders.push_back(shader);
scene->default_light = shader;
}
/* default background */
{
ShaderGraph *graph = new ShaderGraph();
Shader *shader = new Shader();
shader->name = "default_background";
shader->graph = graph;
scene->shaders.push_back(shader);
scene->default_background = shader;
}
/* default empty */
{
ShaderGraph *graph = new ShaderGraph();
Shader *shader = new Shader();
shader->name = "default_empty";
shader->graph = graph;
scene->shaders.push_back(shader);
scene->default_empty = shader;
}
}
void ShaderManager::get_requested_graph_features(ShaderGraph *graph,
DeviceRequestedFeatures *requested_features)
{
foreach(ShaderNode *node, graph->nodes) {
requested_features->max_nodes_group = max(requested_features->max_nodes_group,
node->get_group());
requested_features->nodes_features |= node->get_feature();
if(node->special_type == SHADER_SPECIAL_TYPE_CLOSURE) {
BsdfNode *bsdf_node = static_cast<BsdfNode*>(node);
if(CLOSURE_IS_VOLUME(bsdf_node->closure)) {
requested_features->nodes_features |= NODE_FEATURE_VOLUME;
}
else if(CLOSURE_IS_PRINCIPLED(bsdf_node->closure)) {
requested_features->use_principled = true;
}
}
if(node->has_surface_bssrdf()) {
requested_features->use_subsurface = true;
}
if(node->has_surface_transparent()) {
requested_features->use_transparent = true;
}
if(node->has_raytrace()) {
requested_features->use_shader_raytrace = true;
}
}
}
void ShaderManager::get_requested_features(Scene *scene,
DeviceRequestedFeatures *requested_features)
{
requested_features->max_nodes_group = NODE_GROUP_LEVEL_0;
requested_features->nodes_features = 0;
for(int i = 0; i < scene->shaders.size(); i++) {
Shader *shader = scene->shaders[i];
/* Gather requested features from all the nodes from the graph nodes. */
get_requested_graph_features(shader->graph, requested_features);
ShaderNode *output_node = shader->graph->output();
if(output_node->input("Displacement")->link != NULL) {
requested_features->nodes_features |= NODE_FEATURE_BUMP;
if(shader->displacement_method == DISPLACE_BOTH) {
requested_features->nodes_features |= NODE_FEATURE_BUMP_STATE;
}
}
/* On top of volume nodes, also check if we need volume sampling because
* e.g. an Emission node would slip through the NODE_FEATURE_VOLUME check */
if(shader->has_volume)
requested_features->use_volume |= true;
}
}
void ShaderManager::free_memory()
{
beckmann_table.free_memory();
}
CCL_NAMESPACE_END
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