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blender-archive/intern/cycles/kernel/light/light.h

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C++

/* SPDX-License-Identifier: Apache-2.0
* Copyright 2011-2022 Blender Foundation */
#pragma once
#include "kernel/light/area.h"
#include "kernel/light/background.h"
#include "kernel/light/distant.h"
#include "kernel/light/point.h"
#include "kernel/light/spot.h"
#include "kernel/light/triangle.h"
#include "kernel/sample/mapping.h"
CCL_NAMESPACE_BEGIN
/* Light info. */
ccl_device_inline bool light_select_reached_max_bounces(KernelGlobals kg, int index, int bounce)
{
return (bounce > kernel_data_fetch(lights, index).max_bounces);
}
/* Sample point on an individual light. */
template<bool in_volume_segment>
ccl_device_inline bool light_sample(KernelGlobals kg,
const int lamp,
const float randu,
const float randv,
const float3 P,
const uint32_t path_flag,
ccl_private LightSample *ls)
{
const ccl_global KernelLight *klight = &kernel_data_fetch(lights, lamp);
if (path_flag & PATH_RAY_SHADOW_CATCHER_PASS) {
if (klight->shader_id & SHADER_EXCLUDE_SHADOW_CATCHER) {
return false;
}
}
LightType type = (LightType)klight->type;
ls->type = type;
ls->shader = klight->shader_id;
ls->object = PRIM_NONE;
ls->prim = PRIM_NONE;
ls->lamp = lamp;
ls->u = randu;
ls->v = randv;
ls->group = lamp_lightgroup(kg, lamp);
if (in_volume_segment && (type == LIGHT_DISTANT || type == LIGHT_BACKGROUND)) {
/* Distant lights in a volume get a dummy sample, position will not actually
* be used in that case. Only when sampling from a specific scatter position
* do we actually need to evaluate these. */
ls->P = zero_float3();
ls->Ng = zero_float3();
ls->D = zero_float3();
ls->pdf = 1.0f;
ls->eval_fac = 0.0f;
ls->t = FLT_MAX;
return true;
}
if (type == LIGHT_DISTANT) {
if (!distant_light_sample(klight, randu, randv, ls)) {
return false;
}
}
else if (type == LIGHT_BACKGROUND) {
/* infinite area light (e.g. light dome or env light) */
float3 D = -background_light_sample(kg, P, randu, randv, &ls->pdf);
ls->P = D;
ls->Ng = D;
ls->D = -D;
ls->t = FLT_MAX;
ls->eval_fac = 1.0f;
}
else if (type == LIGHT_SPOT) {
if (!spot_light_sample<in_volume_segment>(klight, randu, randv, P, ls)) {
return false;
}
}
else if (type == LIGHT_POINT) {
if (!point_light_sample<in_volume_segment>(klight, randu, randv, P, ls)) {
return false;
}
}
else {
/* area light */
if (!area_light_sample<in_volume_segment>(klight, randu, randv, P, ls)) {
return false;
}
}
return in_volume_segment || (ls->pdf > 0.0f);
}
/* Sample a point on the chosen emitter. */
template<bool in_volume_segment>
ccl_device_noinline bool light_sample(KernelGlobals kg,
const float randu,
const float randv,
const float time,
const float3 P,
const int bounce,
const uint32_t path_flag,
const int emitter_index,
const float pdf_selection,
ccl_private LightSample *ls)
{
int prim;
MeshLight mesh_light;
if (kernel_data.integrator.use_light_tree) {
ccl_global const KernelLightTreeEmitter *kemitter = &kernel_data_fetch(light_tree_emitters,
emitter_index);
prim = kemitter->prim;
mesh_light = kemitter->mesh_light;
}
else {
ccl_global const KernelLightDistribution *kdistribution = &kernel_data_fetch(
light_distribution, emitter_index);
prim = kdistribution->prim;
mesh_light = kdistribution->mesh_light;
}
/* A different value would be assigned in `triangle_light_sample()` if `!use_light_tree`. */
ls->pdf_selection = pdf_selection;
if (prim >= 0) {
/* Mesh light. */
const int object = mesh_light.object_id;
/* Exclude synthetic meshes from shadow catcher pass. */
if ((path_flag & PATH_RAY_SHADOW_CATCHER_PASS) &&
!(kernel_data_fetch(object_flag, object) & SD_OBJECT_SHADOW_CATCHER)) {
return false;
}
const int shader_flag = mesh_light.shader_flag;
if (!triangle_light_sample<in_volume_segment>(kg, prim, object, randu, randv, time, ls, P)) {
return false;
}
ls->shader |= shader_flag;
}
else {
if (UNLIKELY(light_select_reached_max_bounces(kg, ~prim, bounce))) {
return false;
}
if (!light_sample<in_volume_segment>(kg, ~prim, randu, randv, P, path_flag, ls)) {
return false;
}
}
ls->pdf *= ls->pdf_selection;
return in_volume_segment || (ls->pdf > 0.0f);
}
/* Intersect ray with individual light. */
ccl_device bool lights_intersect(KernelGlobals kg,
IntegratorState state,
ccl_private const Ray *ccl_restrict ray,
ccl_private Intersection *ccl_restrict isect,
const int last_prim,
const int last_object,
const int last_type,
const uint32_t path_flag)
{
for (int lamp = 0; lamp < kernel_data.integrator.num_lights; lamp++) {
const ccl_global KernelLight *klight = &kernel_data_fetch(lights, lamp);
if (path_flag & PATH_RAY_CAMERA) {
if (klight->shader_id & SHADER_EXCLUDE_CAMERA) {
continue;
}
}
else {
if (!(klight->shader_id & SHADER_USE_MIS)) {
continue;
}
#ifdef __MNEE__
/* This path should have been resolved with mnee, it will
* generate a firefly for small lights since it is improbable. */
if ((INTEGRATOR_STATE(state, path, mnee) & PATH_MNEE_CULL_LIGHT_CONNECTION) &&
klight->use_caustics) {
continue;
}
#endif
}
if (path_flag & PATH_RAY_SHADOW_CATCHER_PASS) {
if (klight->shader_id & SHADER_EXCLUDE_SHADOW_CATCHER) {
continue;
}
}
LightType type = (LightType)klight->type;
float t = 0.0f, u = 0.0f, v = 0.0f;
if (type == LIGHT_SPOT) {
if (!spot_light_intersect(klight, ray, &t)) {
continue;
}
}
else if (type == LIGHT_POINT) {
if (!point_light_intersect(klight, ray, &t)) {
continue;
}
}
else if (type == LIGHT_AREA) {
if (!area_light_intersect(klight, ray, &t, &u, &v)) {
continue;
}
}
else {
continue;
}
if (t < isect->t &&
!(last_prim == lamp && last_object == OBJECT_NONE && last_type == PRIMITIVE_LAMP)) {
isect->t = t;
isect->u = u;
isect->v = v;
isect->type = PRIMITIVE_LAMP;
isect->prim = lamp;
isect->object = OBJECT_NONE;
}
}
return isect->prim != PRIM_NONE;
}
/* Setup light sample from intersection. */
ccl_device bool light_sample_from_intersection(KernelGlobals kg,
ccl_private const Intersection *ccl_restrict isect,
const float3 ray_P,
const float3 ray_D,
ccl_private LightSample *ccl_restrict ls)
{
const int lamp = isect->prim;
ccl_global const KernelLight *klight = &kernel_data_fetch(lights, lamp);
LightType type = (LightType)klight->type;
ls->type = type;
ls->shader = klight->shader_id;
ls->object = isect->object;
ls->prim = isect->prim;
ls->lamp = lamp;
/* todo: missing texture coordinates */
ls->t = isect->t;
ls->P = ray_P + ray_D * ls->t;
ls->D = ray_D;
ls->group = lamp_lightgroup(kg, lamp);
if (type == LIGHT_SPOT) {
if (!spot_light_sample_from_intersection(klight, isect, ray_P, ray_D, ls)) {
return false;
}
}
else if (type == LIGHT_POINT) {
if (!point_light_sample_from_intersection(klight, isect, ray_P, ray_D, ls)) {
return false;
}
}
else if (type == LIGHT_AREA) {
if (!area_light_sample_from_intersection(klight, isect, ray_P, ray_D, ls)) {
return false;
}
}
else {
kernel_assert(!"Invalid lamp type in light_sample_from_intersection");
return false;
}
return true;
}
/* Update light sample for changed new position, for MNEE. */
ccl_device_forceinline void light_update_position(KernelGlobals kg,
ccl_private LightSample *ls,
const float3 P)
{
const ccl_global KernelLight *klight = &kernel_data_fetch(lights, ls->lamp);
if (ls->type == LIGHT_POINT) {
point_light_update_position(klight, ls, P);
}
else if (ls->type == LIGHT_SPOT) {
spot_light_update_position(klight, ls, P);
}
else if (ls->type == LIGHT_AREA) {
area_light_update_position(klight, ls, P);
}
}
CCL_NAMESPACE_END