Files
test2/intern/cycles/scene/light.h
Weizhen Huang 9fe87646d5 Cycles: replace spot light disk sampling with sphere sampling
The spotlight is now treated as a sphere instead of a view-aligned disk.
The implementation remains almost identical to that of a point light,
except for the spotlight attenuation and spot blend. There is no
attenuation inside the sphere. Ref #108505

Other changes include:
## Sampling
Instead of sampling the disk area, the new implementation samples either
the cone of the visible portion on the sphere or the spread cone, based
on which cone has a smaller solid angle. This reduces noise when the
spotlight has a large radius and a small spread angle.
| Before | After  |
|   --   |   --   |
|![spot_size_before.png](/attachments/04ea864a-6bf9-40fe-b11b-61c838ae70cf)|![spot_size_after.png](/attachments/7077eaf9-b7a8-41b1-a8b6-aabf1eadb4f4)
## Texture
Spot light can now project texture using UV coordinates.
<video src="/attachments/6db989d2-7a3c-4b41-9340-f5690d48c4fb"
title="spot_light_texture.mp4" controls></video>
## Normalization
Previously, the normalization factor for the spotlight was \(\pi r^2\),
the area of a disk. This factor has been adjusted to \(4\pi r^2\) to
account for the surface area of a sphere. This change also affects point
light since they share the same kernel type.
## Versioning
Some pipeline uses the `Normal` socket of the Texture Coordinate node for
projection, because `ls->Ng` was set to the incoming direction at the
current shading point. Now that `ls->Ng` corresponds to the normal
direction of a point on the sphere (except when the radius is zero),
we replace these nodes with a combination of the Geometry shader node
and the Vector Transform node, which gives the same result as before.
![versioning.png](/attachments/5bbfcacc-26c5-4f7f-8360-c42bcd851f68)
Example file see https://archive.blender.org/developer/T93676

Pull Request: https://projects.blender.org/blender/blender/pulls/109329
2023-07-07 17:15:18 +02:00

171 lines
4.4 KiB
C++

/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
*
* SPDX-License-Identifier: Apache-2.0 */
#ifndef __LIGHT_H__
#define __LIGHT_H__
#include "kernel/types.h"
#include "graph/node.h"
/* included as Light::set_shader defined through NODE_SOCKET_API does not select
* the right Node::set overload as it does not know that Shader is a Node */
#include "scene/shader.h"
#include "util/ies.h"
#include "util/thread.h"
#include "util/types.h"
#include "util/vector.h"
CCL_NAMESPACE_BEGIN
class Device;
class DeviceScene;
class Progress;
class Scene;
class Shader;
class Light : public Node {
public:
NODE_DECLARE;
Light();
NODE_SOCKET_API(LightType, light_type)
NODE_SOCKET_API(float3, strength)
NODE_SOCKET_API(float3, co)
NODE_SOCKET_API(float3, dir)
NODE_SOCKET_API(float, size)
NODE_SOCKET_API(float, angle)
NODE_SOCKET_API(float3, axisu)
NODE_SOCKET_API(float, sizeu)
NODE_SOCKET_API(float3, axisv)
NODE_SOCKET_API(float, sizev)
NODE_SOCKET_API(bool, ellipse)
NODE_SOCKET_API(float, spread)
NODE_SOCKET_API(Transform, tfm)
NODE_SOCKET_API(int, map_resolution)
NODE_SOCKET_API(float, average_radiance)
NODE_SOCKET_API(float, spot_angle)
NODE_SOCKET_API(float, spot_smooth)
NODE_SOCKET_API(bool, cast_shadow)
NODE_SOCKET_API(bool, use_mis)
NODE_SOCKET_API(bool, use_camera)
NODE_SOCKET_API(bool, use_diffuse)
NODE_SOCKET_API(bool, use_glossy)
NODE_SOCKET_API(bool, use_transmission)
NODE_SOCKET_API(bool, use_scatter)
NODE_SOCKET_API(bool, use_caustics)
NODE_SOCKET_API(bool, is_shadow_catcher)
NODE_SOCKET_API(bool, is_portal)
NODE_SOCKET_API(bool, is_enabled)
NODE_SOCKET_API(Shader *, shader)
NODE_SOCKET_API(int, max_bounces)
NODE_SOCKET_API(uint, random_id)
NODE_SOCKET_API(ustring, lightgroup)
NODE_SOCKET_API(uint64_t, light_set_membership);
NODE_SOCKET_API(uint64_t, shadow_set_membership);
/* Normalize power by the surface area of the light. */
NODE_SOCKET_API(bool, normalize)
void tag_update(Scene *scene);
/* Check whether the light has contribution the scene. */
bool has_contribution(Scene *scene);
/* Check whether this light participates in light or shadow linking. */
bool has_light_linking() const;
bool has_shadow_linking() const;
friend class LightManager;
friend class LightTree;
};
class LightManager {
public:
enum : uint32_t {
MESH_NEED_REBUILD = (1 << 0),
EMISSIVE_MESH_MODIFIED = (1 << 1),
LIGHT_MODIFIED = (1 << 2),
LIGHT_ADDED = (1 << 3),
LIGHT_REMOVED = (1 << 4),
OBJECT_MANAGER = (1 << 5),
SHADER_COMPILED = (1 << 6),
SHADER_MODIFIED = (1 << 7),
/* tag everything in the manager for an update */
UPDATE_ALL = ~0u,
UPDATE_NONE = 0u,
};
/* Need to update background (including multiple importance map) */
bool need_update_background;
LightManager();
~LightManager();
/* IES texture management */
int add_ies(const string &ies);
int add_ies_from_file(const string &filename);
void remove_ies(int slot);
void device_update(Device *device, DeviceScene *dscene, Scene *scene, Progress &progress);
void device_free(Device *device, DeviceScene *dscene, const bool free_background = true);
void tag_update(Scene *scene, uint32_t flag);
bool need_update() const;
/* Check whether there is a background light. */
bool has_background_light(Scene *scene);
protected:
/* Optimization: disable light which is either unsupported or
* which doesn't contribute to the scene or which is only used for MIS
* and scene doesn't need MIS.
*/
void test_enabled_lights(Scene *scene);
void device_update_lights(Device *device, DeviceScene *dscene, Scene *scene);
void device_update_distribution(Device *device,
DeviceScene *dscene,
Scene *scene,
Progress &progress);
void device_update_tree(Device *device, DeviceScene *dscene, Scene *scene, Progress &progress);
void device_update_background(Device *device,
DeviceScene *dscene,
Scene *scene,
Progress &progress);
void device_update_ies(DeviceScene *dscene);
struct IESSlot {
IESFile ies;
uint hash;
int users;
};
vector<IESSlot *> ies_slots;
thread_mutex ies_mutex;
bool last_background_enabled;
int last_background_resolution;
uint32_t update_flags;
};
CCL_NAMESPACE_END
#endif /* __LIGHT_H__ */