blender/intern/cycles/render/shader.cpp

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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 "background.h"
#include "blackbody.h"
#include "device.h"
#include "graph.h"
#include "light.h"
#include "mesh.h"
#include "nodes.h"
#include "osl.h"
#include "scene.h"
#include "shader.h"
#include "svm.h"
#include "tables.h"
#include "util_foreach.h"
CCL_NAMESPACE_BEGIN
/* 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;
}
/* 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] = -beckmann_table_slope_max();
CDF_P22_omega_i[0] = 0;
for(int index_slope_x = 1; index_slope_x < DATA_TMP_SIZE; ++index_slope_x) {
/* slope_x */
slope_x[index_slope_x] = -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]);
}
}
}
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 */
Shader::Shader()
{
name = "";
pass_id = 0;
graph = NULL;
graph_bump = NULL;
use_mis = true;
use_transparent_shadow = true;
heterogeneous_volume = true;
volume_sampling_method = VOLUME_SAMPLING_DISTANCE;
volume_interpolation_method = VOLUME_INTERPOLATION_LINEAR;
has_surface = false;
has_surface_transparent = false;
has_surface_emission = false;
has_surface_bssrdf = false;
has_converter_blackbody = false;
has_volume = false;
has_displacement = false;
has_bssrdf_bump = false;
has_heterogeneous_volume = false;
used = false;
need_update = true;
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need_update_attributes = true;
}
Shader::~Shader()
{
delete graph;
delete graph_bump;
}
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_unneeded_nodes();
/* assign graph */
delete graph;
delete graph_bump;
graph = graph_;
graph_bump = 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;
/* 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();
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
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* 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);
/* compare if the attributes changed, mesh manager will check
2012-06-09 17:22:52 +00:00
* need_update_attributes, update the relevant meshes and clear it. */
if(attributes.modified(prev_attributes)) {
need_update_attributes = true;
scene->mesh_manager->need_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;
blackbody_table_offset = TABLE_OFFSET_INVALID;
beckmann_table_offset = TABLE_OFFSET_INVALID;
}
ShaderManager::~ShaderManager()
{
}
ShaderManager *ShaderManager::create(Scene *scene, int shadingsystem)
{
ShaderManager *manager;
#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)
{
/* 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(uint shader, Mesh *mesh, bool smooth)
{
/* get a shader id to pass to the kernel */
int id = shader*2;
/* index depends bump since this setting is not in the shader */
if(mesh && mesh->displacement_method != Mesh::DISPLACE_TRUE)
id += 1;
/* 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 */
foreach(Shader *shader, scene->shaders)
shader->used = false;
scene->shaders[scene->background->shader]->used = true;
scene->shaders[scene->default_surface]->used = true;
scene->shaders[scene->default_light]->used = true;
scene->shaders[scene->default_background]->used = true;
scene->shaders[scene->default_empty]->used = true;
foreach(Mesh *mesh, scene->meshes)
foreach(uint shader, mesh->used_shaders)
scene->shaders[shader]->used = true;
foreach(Light *light, scene->lights)
scene->shaders[light->shader]->used = true;
}
void ShaderManager::device_update_common(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
{
device->tex_free(dscene->shader_flag);
dscene->shader_flag.clear();
if(scene->shaders.size() == 0)
return;
uint shader_flag_size = scene->shaders.size()*4;
uint *shader_flag = dscene->shader_flag.resize(shader_flag_size);
uint i = 0;
bool has_converter_blackbody = false;
bool has_volumes = 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;
/* in this case we can assume transparent surface */
if(!shader->has_surface)
flag |= SD_HAS_ONLY_VOLUME;
/* todo: this could check more fine grained, to skip useless volumes
* enclosed inside an opaque bsdf, although we still need to handle
* the case with camera inside volumes too */
flag |= SD_HAS_TRANSPARENT_SHADOW;
}
if(shader->heterogeneous_volume && shader->has_heterogeneous_volume)
flag |= SD_HETEROGENEOUS_VOLUME;
if(shader->has_bssrdf_bump)
flag |= SD_HAS_BSSRDF_BUMP;
if(shader->has_converter_blackbody)
has_converter_blackbody = true;
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->graph_bump)
flag |= SD_HAS_BUMP;
/* regular shader */
shader_flag[i++] = flag;
shader_flag[i++] = shader->pass_id;
/* shader with bump mapping */
if(shader->graph_bump)
flag |= SD_HAS_BSSRDF_BUMP;
shader_flag[i++] = flag;
shader_flag[i++] = shader->pass_id;
}
device->tex_alloc("__shader_flag", dscene->shader_flag);
/* blackbody lookup table */
KernelTables *ktables = &dscene->data.tables;
if(has_converter_blackbody && blackbody_table_offset == TABLE_OFFSET_INVALID) {
vector<float> table = blackbody_table();
blackbody_table_offset = scene->lookup_tables->add_table(dscene, table);
ktables->blackbody_offset = (int)blackbody_table_offset;
}
else if(!has_converter_blackbody && blackbody_table_offset != TABLE_OFFSET_INVALID) {
scene->lookup_tables->remove_table(blackbody_table_offset);
blackbody_table_offset = TABLE_OFFSET_INVALID;
}
/* beckmann lookup table */
if(beckmann_table_offset == TABLE_OFFSET_INVALID) {
vector<float> table;
beckmann_table_build(table);
beckmann_table_offset = scene->lookup_tables->add_table(dscene, table);
ktables->beckmann_offset = (int)beckmann_table_offset;
}
/* integrator */
KernelIntegrator *kintegrator = &dscene->data.integrator;
kintegrator->use_volumes = has_volumes;
}
void ShaderManager::device_free_common(Device *device, DeviceScene *dscene, Scene *scene)
{
if(blackbody_table_offset != TABLE_OFFSET_INVALID) {
scene->lookup_tables->remove_table(blackbody_table_offset);
blackbody_table_offset = TABLE_OFFSET_INVALID;
}
if(beckmann_table_offset != TABLE_OFFSET_INVALID) {
scene->lookup_tables->remove_table(beckmann_table_offset);
beckmann_table_offset = TABLE_OFFSET_INVALID;
}
device->tex_free(dscene->shader_flag);
dscene->shader_flag.clear();
}
void ShaderManager::add_default(Scene *scene)
{
Shader *shader;
ShaderGraph *graph;
ShaderNode *closure, *out;
/* default surface */
{
graph = new ShaderGraph();
closure = graph->add(new DiffuseBsdfNode());
closure->input("Color")->value = make_float3(0.8f, 0.8f, 0.8f);
out = graph->output();
graph->connect(closure->output("BSDF"), out->input("Surface"));
shader = new Shader();
shader->name = "default_surface";
shader->graph = graph;
scene->shaders.push_back(shader);
scene->default_surface = scene->shaders.size() - 1;
}
/* default light */
{
graph = new ShaderGraph();
closure = graph->add(new EmissionNode());
closure->input("Color")->value = make_float3(0.8f, 0.8f, 0.8f);
closure->input("Strength")->value.x = 0.0f;
out = graph->output();
graph->connect(closure->output("Emission"), out->input("Surface"));
shader = new Shader();
shader->name = "default_light";
shader->graph = graph;
scene->shaders.push_back(shader);
scene->default_light = scene->shaders.size() - 1;
}
/* default background */
{
graph = new ShaderGraph();
shader = new Shader();
shader->name = "default_background";
shader->graph = graph;
scene->shaders.push_back(shader);
scene->default_background = scene->shaders.size() - 1;
}
/* default empty */
{
graph = new ShaderGraph();
shader = new Shader();
shader->name = "default_empty";
shader->graph = graph;
scene->shaders.push_back(shader);
scene->default_empty = scene->shaders.size() - 1;
}
}
CCL_NAMESPACE_END