blender/intern/cycles/render/svm.h
Brecht Van Lommel de9dffc61e Cycles: initial subsurface multiple scattering support. It's not working as
well as I would like, but it works, just add a subsurface scattering node and
you can use it like any other BSDF.

It is using fully raytraced sampling compatible with progressive rendering
and other more advanced rendering algorithms we might used in the future, and
it uses no extra memory so it's suitable for complex scenes.

Disadvantage is that it can be quite noisy and slow. Two limitations that will
be solved are that it does not work with bump mapping yet, and that the falloff
function used is a simple cubic function, it's not using the real BSSRDF
falloff function yet.

The node has a color input, along with a scattering radius for each RGB color
channel along with an overall scale factor for the radii.

There is also no GPU support yet, will test if I can get that working later.

Node Documentation:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/Shaders#BSSRDF

Implementation notes:
http://wiki.blender.org/index.php/Dev:2.6/Source/Render/Cycles/Subsurface_Scattering
2013-04-01 20:26:52 +00:00

154 lines
4.1 KiB
C++

/*
* 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.
*/
#ifndef __SVM_H__
#define __SVM_H__
#include "attribute.h"
#include "graph.h"
#include "shader.h"
#include "util_set.h"
#include "util_string.h"
CCL_NAMESPACE_BEGIN
class Device;
class DeviceScene;
class ImageManager;
struct KernelSunSky;
class Scene;
class ShaderGraph;
class ShaderInput;
class ShaderNode;
class ShaderOutput;
/* Shader Manager */
class SVMShaderManager : public ShaderManager {
public:
SVMShaderManager();
~SVMShaderManager();
void reset(Scene *scene);
void device_update(Device *device, DeviceScene *dscene, Scene *scene, Progress& progress);
void device_free(Device *device, DeviceScene *dscene, Scene *scene);
};
/* Graph Compiler */
class SVMCompiler {
public:
SVMCompiler(ShaderManager *shader_manager, ImageManager *image_manager,
bool use_multi_closure_);
void compile(Shader *shader, vector<int4>& svm_nodes, int index);
void stack_assign(ShaderOutput *output);
void stack_assign(ShaderInput *input);
int stack_find_offset(ShaderSocketType type);
void stack_clear_offset(ShaderSocketType type, int offset);
void stack_link(ShaderInput *input, ShaderOutput *output);
void add_node(NodeType type, int a = 0, int b = 0, int c = 0);
void add_node(int a = 0, int b = 0, int c = 0, int d = 0);
void add_node(NodeType type, const float3& f);
void add_node(const float4& f);
void add_array(float4 *f, int num);
uint attribute(ustring name);
uint attribute(AttributeStandard std);
uint encode_uchar4(uint x, uint y = 0, uint z = 0, uint w = 0);
uint closure_mix_weight_offset() { return mix_weight_offset; }
ShaderType output_type() { return current_type; }
ImageManager *image_manager;
ShaderManager *shader_manager;
KernelSunSky *sunsky;
bool background;
protected:
/* stack */
struct Stack {
Stack() { memset(users, 0, sizeof(users)); }
Stack(const Stack& other) { memcpy(users, other.users, sizeof(users)); }
Stack& operator=(const Stack& other) { memcpy(users, other.users, sizeof(users)); return *this; }
bool empty()
{
for(int i = 0; i < SVM_STACK_SIZE; i++)
if(users[i])
return false;
return true;
}
void print()
{
printf("stack <");
for(int i = 0; i < SVM_STACK_SIZE; i++)
printf((users[i])? "*": " ");
printf(">\n");
}
int users[SVM_STACK_SIZE];
};
struct StackBackup {
Stack stack;
vector<int> offsets;
set<ShaderNode*> done;
};
void stack_backup(StackBackup& backup, set<ShaderNode*>& done);
void stack_restore(StackBackup& backup, set<ShaderNode*>& done);
void stack_clear_temporary(ShaderNode *node);
int stack_size(ShaderSocketType type);
void stack_clear_users(ShaderNode *node, set<ShaderNode*>& done);
bool node_skip_input(ShaderNode *node, ShaderInput *input);
/* single closure */
void find_dependencies(set<ShaderNode*>& dependencies, const set<ShaderNode*>& done, ShaderInput *input);
void generate_svm_nodes(const set<ShaderNode*>& nodes, set<ShaderNode*>& done);
void generate_closure(ShaderNode *node, set<ShaderNode*>& done);
/* multi closure */
void generate_multi_closure(ShaderNode *node, set<ShaderNode*>& done, set<ShaderNode*>& closure_done);
/* compile */
void compile_type(Shader *shader, ShaderGraph *graph, ShaderType type);
vector<int4> svm_nodes;
ShaderType current_type;
Shader *current_shader;
ShaderGraph *current_graph;
Stack active_stack;
int max_stack_use;
uint mix_weight_offset;
bool use_multi_closure;
};
CCL_NAMESPACE_END
#endif /* __SVM_H__ */