blender/intern/cycles/render/light.cpp

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/*
* Copyright 2011, Blender Foundation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "device.h"
#include "integrator.h"
#include "light.h"
#include "mesh.h"
#include "object.h"
#include "scene.h"
#include "shader.h"
#include "util_foreach.h"
#include "util_progress.h"
CCL_NAMESPACE_BEGIN
static void dump_background_pixels(Device *device, DeviceScene *dscene, int res, vector<float3>& pixels)
{
/* create input */
int width = res;
int height = res;
device_vector<uint4> d_input;
device_vector<float4> d_output;
uint4 *d_input_data = d_input.resize(width*height);
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
float u = x/(float)width;
float v = y/(float)height;
uint4 in = make_uint4(__float_as_int(u), __float_as_int(v), 0, 0);
d_input_data[x + y*width] = in;
}
}
/* compute on device */
float4 *d_output_data = d_output.resize(width*height);
memset((void*)d_output.data_pointer, 0, d_output.memory_size());
device->const_copy_to("__data", &dscene->data, sizeof(dscene->data));
device->mem_alloc(d_input, MEM_READ_ONLY);
device->mem_copy_to(d_input);
device->mem_alloc(d_output, MEM_WRITE_ONLY);
DeviceTask main_task(DeviceTask::SHADER);
main_task.shader_input = d_input.device_pointer;
main_task.shader_output = d_output.device_pointer;
main_task.shader_eval_type = SHADER_EVAL_BACKGROUND;
main_task.shader_x = 0;
main_task.shader_w = width*height;
/* disabled splitting for now, there's an issue with multi-GPU mem_copy_from */
list<DeviceTask> split_tasks;
main_task.split_max_size(split_tasks, 128*128);
foreach(DeviceTask& task, split_tasks) {
device->task_add(task);
device->task_wait();
device->mem_copy_from(d_output, task.shader_x, 1, task.shader_w, sizeof(float4));
}
device->mem_free(d_input);
device->mem_free(d_output);
d_output_data = reinterpret_cast<float4*>(d_output.data_pointer);
pixels.resize(width*height);
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
pixels[y*width + x].x = d_output_data[y*width + x].x;
pixels[y*width + x].y = d_output_data[y*width + x].y;
pixels[y*width + x].z = d_output_data[y*width + x].z;
}
}
}
/* Light */
Light::Light()
{
type = LIGHT_POINT;
co = make_float3(0.0f, 0.0f, 0.0f);
dir = make_float3(0.0f, 0.0f, 0.0f);
size = 0.0f;
axisu = make_float3(0.0f, 0.0f, 0.0f);
sizeu = 1.0f;
axisv = make_float3(0.0f, 0.0f, 0.0f);
sizev = 1.0f;
map_resolution = 512;
spot_angle = M_PI_4_F;
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spot_smooth = 0.0f;
cast_shadow = true;
use_mis = false;
shader = 0;
samples = 1;
}
void Light::tag_update(Scene *scene)
{
scene->light_manager->need_update = true;
}
/* Light Manager */
LightManager::LightManager()
{
need_update = true;
}
LightManager::~LightManager()
{
}
void LightManager::device_update_distribution(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
{
progress.set_status("Updating Lights", "Computing distribution");
/* count */
size_t num_lights = scene->lights.size();
size_t num_background_lights = 0;
size_t num_triangles = 0;
size_t num_curve_segments = 0;
foreach(Object *object, scene->objects) {
Mesh *mesh = object->mesh;
bool have_emission = false;
/* skip if we are not visible for BSDFs */
if(!(object->visibility & (PATH_RAY_DIFFUSE|PATH_RAY_GLOSSY|PATH_RAY_TRANSMIT)))
continue;
/* skip if we have no emission shaders */
foreach(uint sindex, mesh->used_shaders) {
Shader *shader = scene->shaders[sindex];
if(shader->sample_as_light && shader->has_surface_emission) {
have_emission = true;
break;
}
}
/* count triangles */
if(have_emission) {
for(size_t i = 0; i < mesh->triangles.size(); i++) {
Shader *shader = scene->shaders[mesh->shader[i]];
if(shader->sample_as_light && shader->has_surface_emission)
num_triangles++;
}
/* disabled for curves */
#if 0
foreach(Mesh::Curve& curve, mesh->curves) {
Shader *shader = scene->shaders[curve.shader];
if(shader->sample_as_light && shader->has_surface_emission)
num_curve_segments += curve.num_segments();
#endif
}
}
size_t num_distribution = num_triangles + num_curve_segments;
num_distribution += num_lights;
/* emission area */
float4 *distribution = dscene->light_distribution.resize(num_distribution + 1);
float totarea = 0.0f;
/* triangles */
size_t offset = 0;
int j = 0;
foreach(Object *object, scene->objects) {
Mesh *mesh = object->mesh;
bool have_emission = false;
/* skip if we are not visible for BSDFs */
if(!(object->visibility & (PATH_RAY_DIFFUSE|PATH_RAY_GLOSSY|PATH_RAY_TRANSMIT))) {
j++;
continue;
}
/* skip if we have no emission shaders */
foreach(uint sindex, mesh->used_shaders) {
Shader *shader = scene->shaders[sindex];
if(shader->sample_as_light && shader->has_surface_emission) {
have_emission = true;
break;
}
}
/* sum area */
if(have_emission) {
bool transform_applied = mesh->transform_applied;
Transform tfm = object->tfm;
int object_id = j;
if(transform_applied)
object_id = ~object_id;
for(size_t i = 0; i < mesh->triangles.size(); i++) {
Shader *shader = scene->shaders[mesh->shader[i]];
if(shader->sample_as_light && shader->has_surface_emission) {
distribution[offset].x = totarea;
distribution[offset].y = __int_as_float(i + mesh->tri_offset);
distribution[offset].z = __int_as_float(~0);
distribution[offset].w = __int_as_float(object_id);
offset++;
Mesh::Triangle t = mesh->triangles[i];
float3 p1 = mesh->verts[t.v[0]];
float3 p2 = mesh->verts[t.v[1]];
float3 p3 = mesh->verts[t.v[2]];
if(!transform_applied) {
p1 = transform_point(&tfm, p1);
p2 = transform_point(&tfm, p2);
p3 = transform_point(&tfm, p3);
}
totarea += triangle_area(p1, p2, p3);
}
}
/*sample as light disabled for strands*/
#if 0
size_t i = 0;
foreach(Mesh::Curve& curve, mesh->curves) {
Shader *shader = scene->shaders[curve.shader];
int first_key = curve.first_key;
if(shader->sample_as_light && shader->has_surface_emission) {
for(int j = 0; j < curve.num_segments(); j++) {
distribution[offset].x = totarea;
distribution[offset].y = __int_as_float(i + mesh->curve_offset); // XXX fix kernel code
distribution[offset].z = __int_as_float(j);
distribution[offset].w = __int_as_float(object_id);
offset++;
float3 p1 = mesh->curve_keys[first_key + j].loc;
float r1 = mesh->curve_keys[first_key + j].radius;
float3 p2 = mesh->curve_keys[first_key + j + 1].loc;
float r2 = mesh->curve_keys[first_key + j + 1].radius;
if(!transform_applied) {
p1 = transform_point(&tfm, p1);
p2 = transform_point(&tfm, p2);
}
totarea += M_PI_F * (r1 + r2) * len(p1 - p2);
}
}
i++;
}
#endif
}
if(progress.get_cancel()) return;
j++;
}
float trianglearea = totarea;
/* point lights */
float lightarea = (totarea > 0.0f)? totarea/scene->lights.size(): 1.0f;
bool use_lamp_mis = false;
for(int i = 0; i < scene->lights.size(); i++, offset++) {
Light *light = scene->lights[i];
distribution[offset].x = totarea;
distribution[offset].y = __int_as_float(~(int)i);
distribution[offset].z = 1.0f;
distribution[offset].w = light->size;
totarea += lightarea;
if(light->size > 0.0f && light->use_mis)
use_lamp_mis = true;
if(light->type == LIGHT_BACKGROUND)
num_background_lights++;
}
/* normalize cumulative distribution functions */
distribution[num_distribution].x = totarea;
distribution[num_distribution].y = 0.0f;
distribution[num_distribution].z = 0.0f;
distribution[num_distribution].w = 0.0f;
if(totarea > 0.0f) {
for(size_t i = 0; i < num_distribution; i++)
distribution[i].x /= totarea;
distribution[num_distribution].x = 1.0f;
}
if(progress.get_cancel()) return;
/* update device */
KernelIntegrator *kintegrator = &dscene->data.integrator;
KernelFilm *kfilm = &dscene->data.film;
kintegrator->use_direct_light = (totarea > 0.0f);
if(kintegrator->use_direct_light) {
/* number of emissives */
kintegrator->num_distribution = num_distribution;
/* precompute pdfs */
kintegrator->pdf_triangles = 0.0f;
kintegrator->pdf_lights = 0.0f;
kintegrator->inv_pdf_lights = 0.0f;
/* sample one, with 0.5 probability of light or triangle */
kintegrator->num_all_lights = num_lights;
if(trianglearea > 0.0f) {
kintegrator->pdf_triangles = 1.0f/trianglearea;
if(num_lights)
kintegrator->pdf_triangles *= 0.5f;
}
if(num_lights) {
kintegrator->pdf_lights = 1.0f/num_lights;
if(trianglearea > 0.0f)
kintegrator->pdf_lights *= 0.5f;
kintegrator->inv_pdf_lights = 1.0f/kintegrator->pdf_lights;
}
kintegrator->use_lamp_mis = use_lamp_mis;
/* bit of an ugly hack to compensate for emitting triangles influencing
* amount of samples we get for this pass */
kfilm->pass_shadow_scale = 1.0f;
if(kintegrator->pdf_triangles != 0.0f)
kfilm->pass_shadow_scale *= 0.5f;
if(num_background_lights < num_lights)
kfilm->pass_shadow_scale *= (float)(num_lights - num_background_lights)/(float)num_lights;
/* CDF */
device->tex_alloc("__light_distribution", dscene->light_distribution);
}
else {
dscene->light_distribution.clear();
kintegrator->num_distribution = 0;
kintegrator->num_all_lights = 0;
kintegrator->pdf_triangles = 0.0f;
kintegrator->pdf_lights = 0.0f;
kintegrator->inv_pdf_lights = 0.0f;
kintegrator->use_lamp_mis = false;
kfilm->pass_shadow_scale = 1.0f;
}
}
void LightManager::device_update_background(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
{
KernelIntegrator *kintegrator = &dscene->data.integrator;
Light *background_light = NULL;
/* find background light */
foreach(Light *light, scene->lights) {
if(light->type == LIGHT_BACKGROUND) {
background_light = light;
break;
}
}
/* no background light found, signal renderer to skip sampling */
if(!background_light) {
kintegrator->pdf_background_res = 0;
return;
}
progress.set_status("Updating Lights", "Importance map");
assert(kintegrator->use_direct_light);
/* get the resolution from the light's size (we stuff it in there) */
int res = background_light->map_resolution;
kintegrator->pdf_background_res = res;
assert(res > 0);
vector<float3> pixels;
dump_background_pixels(device, dscene, res, pixels);
if(progress.get_cancel())
return;
/* build row distributions and column distribution for the infinite area environment light */
int cdf_count = res + 1;
float2 *marg_cdf = dscene->light_background_marginal_cdf.resize(cdf_count);
float2 *cond_cdf = dscene->light_background_conditional_cdf.resize(cdf_count * cdf_count);
/* conditional CDFs (rows, U direction) */
for(int i = 0; i < res; i++) {
float sin_theta = sinf(M_PI_F * (i + 0.5f) / res);
float3 env_color = pixels[i * res];
float ave_luminamce = average(env_color);
cond_cdf[i * cdf_count].x = ave_luminamce * sin_theta;
cond_cdf[i * cdf_count].y = 0.0f;
for(int j = 1; j < res; j++) {
env_color = pixels[i * res + j];
ave_luminamce = average(env_color);
cond_cdf[i * cdf_count + j].x = ave_luminamce * sin_theta;
cond_cdf[i * cdf_count + j].y = cond_cdf[i * cdf_count + j - 1].y + cond_cdf[i * cdf_count + j - 1].x / res;
}
float cdf_total = cond_cdf[i * cdf_count + res - 1].y + cond_cdf[i * cdf_count + res - 1].x / res;
/* stuff the total into the brightness value for the last entry, because
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* we are going to normalize the CDFs to 0.0 to 1.0 afterwards */
cond_cdf[i * cdf_count + res].x = cdf_total;
if(cdf_total > 0.0f)
for(int j = 1; j < res; j++)
cond_cdf[i * cdf_count + j].y /= cdf_total;
cond_cdf[i * cdf_count + res].y = 1.0f;
}
/* marginal CDFs (column, V direction, sum of rows) */
marg_cdf[0].x = cond_cdf[res].x;
marg_cdf[0].y = 0.0f;
for(int i = 1; i < res; i++) {
marg_cdf[i].x = cond_cdf[i * cdf_count + res].x;
marg_cdf[i].y = marg_cdf[i - 1].y + marg_cdf[i - 1].x / res;
}
float cdf_total = marg_cdf[res - 1].y + marg_cdf[res - 1].x / res;
marg_cdf[res].x = cdf_total;
if(cdf_total > 0.0f)
for(int i = 1; i < res; i++)
marg_cdf[i].y /= cdf_total;
marg_cdf[res].y = 1.0f;
/* update device */
device->tex_alloc("__light_background_marginal_cdf", dscene->light_background_marginal_cdf);
device->tex_alloc("__light_background_conditional_cdf", dscene->light_background_conditional_cdf);
}
void LightManager::device_update_points(Device *device, DeviceScene *dscene, Scene *scene)
{
if(scene->lights.size() == 0)
return;
float4 *light_data = dscene->light_data.resize(scene->lights.size()*LIGHT_SIZE);
if(!device->info.advanced_shading) {
/* remove unsupported light */
foreach(Light *light, scene->lights) {
if(light->type == LIGHT_BACKGROUND) {
scene->lights.erase(std::remove(scene->lights.begin(), scene->lights.end(), light), scene->lights.end());
break;
}
}
}
for(size_t i = 0; i < scene->lights.size(); i++) {
Light *light = scene->lights[i];
float3 co = light->co;
float3 dir = normalize(light->dir);
int shader_id = scene->shader_manager->get_shader_id(scene->lights[i]->shader);
float samples = __int_as_float(light->samples);
if(!light->cast_shadow)
shader_id &= ~SHADER_CAST_SHADOW;
if(light->type == LIGHT_POINT) {
shader_id &= ~SHADER_AREA_LIGHT;
float radius = light->size;
float invarea = (radius > 0.0f)? 1.0f/(M_PI_F*radius*radius): 1.0f;
if(light->use_mis && radius > 0.0f)
shader_id |= SHADER_USE_MIS;
light_data[i*LIGHT_SIZE + 0] = make_float4(__int_as_float(light->type), co.x, co.y, co.z);
light_data[i*LIGHT_SIZE + 1] = make_float4(__int_as_float(shader_id), radius, invarea, 0.0f);
light_data[i*LIGHT_SIZE + 2] = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
light_data[i*LIGHT_SIZE + 3] = make_float4(samples, 0.0f, 0.0f, 0.0f);
}
else if(light->type == LIGHT_DISTANT) {
shader_id &= ~SHADER_AREA_LIGHT;
float radius = light->size;
float angle = atanf(radius);
float cosangle = cosf(angle);
float area = M_PI_F*radius*radius;
float invarea = (area > 0.0f)? 1.0f/area: 1.0f;
if(light->use_mis && area > 0.0f)
shader_id |= SHADER_USE_MIS;
light_data[i*LIGHT_SIZE + 0] = make_float4(__int_as_float(light->type), dir.x, dir.y, dir.z);
light_data[i*LIGHT_SIZE + 1] = make_float4(__int_as_float(shader_id), radius, cosangle, invarea);
light_data[i*LIGHT_SIZE + 2] = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
light_data[i*LIGHT_SIZE + 3] = make_float4(samples, 0.0f, 0.0f, 0.0f);
}
else if(light->type == LIGHT_BACKGROUND) {
shader_id &= ~SHADER_AREA_LIGHT;
shader_id |= SHADER_USE_MIS;
light_data[i*LIGHT_SIZE + 0] = make_float4(__int_as_float(light->type), 0.0f, 0.0f, 0.0f);
light_data[i*LIGHT_SIZE + 1] = make_float4(__int_as_float(shader_id), 0.0f, 0.0f, 0.0f);
light_data[i*LIGHT_SIZE + 2] = make_float4(0.0f, 0.0f, 0.0f, 0.0f);
light_data[i*LIGHT_SIZE + 3] = make_float4(samples, 0.0f, 0.0f, 0.0f);
}
else if(light->type == LIGHT_AREA) {
float3 axisu = light->axisu*(light->sizeu*light->size);
float3 axisv = light->axisv*(light->sizev*light->size);
float area = len(axisu)*len(axisv);
float invarea = (area > 0.0f)? 1.0f/area: 1.0f;
if(light->use_mis && area > 0.0f)
shader_id |= SHADER_USE_MIS;
light_data[i*LIGHT_SIZE + 0] = make_float4(__int_as_float(light->type), co.x, co.y, co.z);
light_data[i*LIGHT_SIZE + 1] = make_float4(__int_as_float(shader_id), axisu.x, axisu.y, axisu.z);
light_data[i*LIGHT_SIZE + 2] = make_float4(invarea, axisv.x, axisv.y, axisv.z);
light_data[i*LIGHT_SIZE + 3] = make_float4(samples, dir.x, dir.y, dir.z);
}
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else if(light->type == LIGHT_SPOT) {
shader_id &= ~SHADER_AREA_LIGHT;
float radius = light->size;
float invarea = (radius > 0.0f)? 1.0f/(M_PI_F*radius*radius): 1.0f;
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float spot_angle = cosf(light->spot_angle*0.5f);
float spot_smooth = (1.0f - spot_angle)*light->spot_smooth;
if(light->use_mis && radius > 0.0f)
shader_id |= SHADER_USE_MIS;
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light_data[i*LIGHT_SIZE + 0] = make_float4(__int_as_float(light->type), co.x, co.y, co.z);
light_data[i*LIGHT_SIZE + 1] = make_float4(__int_as_float(shader_id), radius, invarea, spot_angle);
light_data[i*LIGHT_SIZE + 2] = make_float4(spot_smooth, dir.x, dir.y, dir.z);
light_data[i*LIGHT_SIZE + 3] = make_float4(samples, 0.0f, 0.0f, 0.0f);
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}
}
device->tex_alloc("__light_data", dscene->light_data);
}
void LightManager::device_update(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress)
{
if(!need_update)
return;
device_free(device, dscene);
device_update_points(device, dscene, scene);
if(progress.get_cancel()) return;
device_update_distribution(device, dscene, scene, progress);
if(progress.get_cancel()) return;
device_update_background(device, dscene, scene, progress);
if(progress.get_cancel()) return;
need_update = false;
}
void LightManager::device_free(Device *device, DeviceScene *dscene)
{
device->tex_free(dscene->light_distribution);
device->tex_free(dscene->light_data);
device->tex_free(dscene->light_background_marginal_cdf);
device->tex_free(dscene->light_background_conditional_cdf);
dscene->light_distribution.clear();
dscene->light_data.clear();
dscene->light_background_marginal_cdf.clear();
dscene->light_background_conditional_cdf.clear();
}
void LightManager::tag_update(Scene *scene)
{
need_update = true;
}
CCL_NAMESPACE_END