blender/intern/cycles/kernel/kernel_displace.h
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

70 lines
2.0 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.
*/
CCL_NAMESPACE_BEGIN
__device void kernel_shader_evaluate(KernelGlobals *kg, uint4 *input, float4 *output, ShaderEvalType type, int i)
{
ShaderData sd;
uint4 in = input[i];
float3 out;
if(type == SHADER_EVAL_DISPLACE) {
/* setup shader data */
int object = in.x;
int prim = in.y;
float u = __int_as_float(in.z);
float v = __int_as_float(in.w);
shader_setup_from_displace(kg, &sd, object, prim, u, v);
/* evaluate */
float3 P = sd.P;
shader_eval_displacement(kg, &sd);
out = sd.P - P;
}
else { // SHADER_EVAL_BACKGROUND
/* setup ray */
Ray ray;
ray.P = make_float3(0.0f, 0.0f, 0.0f);
ray.D = make_float3(__int_as_float(in.x), __int_as_float(in.y), __int_as_float(in.z));
ray.t = 0.0f;
#ifdef __RAY_DIFFERENTIALS__
ray.dD.dx = make_float3(0.0f, 0.0f, 0.0f);
ray.dD.dy = make_float3(0.0f, 0.0f, 0.0f);
ray.dP.dx = make_float3(0.0f, 0.0f, 0.0f);
ray.dP.dy = make_float3(0.0f, 0.0f, 0.0f);
#endif
/* setup shader data */
shader_setup_from_background(kg, &sd, &ray);
/* evaluate */
int flag = 0; /* we can't know which type of BSDF this is for */
out = shader_eval_background(kg, &sd, flag);
}
/* write output */
output[i] = make_float4(out.x, out.y, out.z, 0.0f);
}
CCL_NAMESPACE_END