blender/intern/cycles/render/mesh_displace.cpp
Brecht Van Lommel 5873301257 Sample as Lamp option for world shaders, to enable multiple importance sampling.
By default lighting from the world is computed solely with indirect light
sampling. However for more complex environment maps this can be too noisy, as
sampling the BSDF may not easily find the highlights in the environment map
image. By enabling this option, the world background will be sampled as a lamp,
with lighter parts automatically given more samples.

Map Resolution specifies the size of the importance map (res x res). Before
rendering starts, an importance map is generated by "baking" a grayscale image
from the world shader. This will then be used to determine which parts of the
background are light and so should receive more samples than darker parts.
Higher resolutions will result in more accurate sampling but take more setup
time and memory.

Patch by Mike Farnsworth, thanks!
2012-01-20 17:49:17 +00:00

156 lines
3.9 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.
*/
#include "device.h"
#include "mesh.h"
#include "scene.h"
#include "shader.h"
#include "util_foreach.h"
#include "util_progress.h"
CCL_NAMESPACE_BEGIN
bool MeshManager::displace(Device *device, Scene *scene, Mesh *mesh, Progress& progress)
{
/* verify if we have a displacement shader */
bool has_displacement = false;
if(mesh->displacement_method != Mesh::DISPLACE_BUMP) {
foreach(uint sindex, mesh->used_shaders)
if(scene->shaders[sindex]->has_displacement)
has_displacement = true;
}
if(!has_displacement)
return false;
/* setup input for device task */
vector<bool> done(mesh->verts.size(), false);
device_vector<uint4> d_input;
uint4 *d_input_data = d_input.resize(mesh->verts.size());
size_t d_input_offset = 0;
for(size_t i = 0; i < mesh->triangles.size(); i++) {
Mesh::Triangle t = mesh->triangles[i];
Shader *shader = scene->shaders[mesh->shader[i]];
if(!shader->has_displacement)
continue;
for(int j = 0; j < 3; j++) {
if(done[t.v[j]])
continue;
done[t.v[j]] = true;
/* set up object, primitive and barycentric coordinates */
/* when used, non-instanced convention: object = -object-1; */
int object = ~0; /* todo */
int prim = mesh->tri_offset + i;
float u, v;
if(j == 0) {
u = 1.0f;
v = 0.0f;
}
else if(j == 1) {
u = 0.0f;
v = 1.0f;
}
else {
u = 0.0f;
v = 0.0f;
}
/* back */
uint4 in = make_uint4(object, prim, __float_as_int(u), __float_as_int(v));
d_input_data[d_input_offset++] = in;
}
}
if(d_input_offset == 0)
return false;
/* run device task */
device_vector<float4> d_output;
d_output.resize(d_input.size());
device->mem_alloc(d_input, MEM_READ_ONLY);
device->mem_copy_to(d_input);
device->mem_alloc(d_output, MEM_WRITE_ONLY);
DeviceTask task(DeviceTask::SHADER);
task.shader_input = d_input.device_pointer;
task.shader_output = d_output.device_pointer;
task.shader_eval_type = SHADER_EVAL_DISPLACE;
task.shader_x = 0;
task.shader_w = d_input.size();
device->task_add(task);
device->task_wait();
device->mem_copy_from(d_output, 0, 1, d_output.size(), sizeof(float4));
device->mem_free(d_input);
device->mem_free(d_output);
if(progress.get_cancel())
return false;
/* read result */
done.clear();
done.resize(mesh->verts.size(), false);
int k = 0;
float4 *offset = (float4*)d_output.data_pointer;
for(size_t i = 0; i < mesh->triangles.size(); i++) {
Mesh::Triangle t = mesh->triangles[i];
Shader *shader = scene->shaders[mesh->shader[i]];
if(!shader->has_displacement)
continue;
for(int j = 0; j < 3; j++) {
if(!done[t.v[j]]) {
done[t.v[j]] = true;
float3 off = float4_to_float3(offset[k++]);
mesh->verts[t.v[j]] += off;
}
}
}
/* for displacement method both, we only need to recompute the face
* normals, as bump mapping in the shader will already alter the
* vertex normal, so we start from the non-displaced vertex normals
* to avoid applying the perturbation twice. */
mesh->attributes.remove(Attribute::STD_FACE_NORMAL);
mesh->add_face_normals();
if(mesh->displacement_method == Mesh::DISPLACE_TRUE) {
mesh->attributes.remove(Attribute::STD_VERTEX_NORMAL);
mesh->add_vertex_normals();
}
return true;
}
CCL_NAMESPACE_END