Clément Foucault
83ac8628c4
This modifies the principled BSDF and the Glass BSDF which now have better fit to multiscatter GGX. Code to generate the LUT have been updated and can run at runtime. The refraction LUT has been changed to have the critical angle always centered around one pixel so that interpolation can be mitigated. Offline LUT data will be updated in another commit This simplify the BTDF retreival removing the manual clean cut at low roughness. This maximize the precision of the LUT by scalling the sides by the critical angle. I also touched the ior > 1.0 approximation to be smoother. Also incluse some cleanup of bsdf_sampling.glsl
124 lines
4.1 KiB
C
124 lines
4.1 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* Copyright 2020, Blender Foundation.
|
|
*/
|
|
|
|
/** \file
|
|
* \ingroup draw_engine
|
|
*
|
|
* EEVEE LUT generation:
|
|
*
|
|
* Routine to generate the LUT used by eevee stored in eevee_lut.h
|
|
* These functions are not to be used in the final executable.
|
|
*/
|
|
|
|
#include "DRW_render.h"
|
|
|
|
#include "BLI_fileops.h"
|
|
#include "BLI_rand.h"
|
|
#include "BLI_string_utils.h"
|
|
|
|
#include "eevee_private.h"
|
|
|
|
#define DO_FILE_OUTPUT 0
|
|
|
|
float *EEVEE_lut_update_ggx_brdf(int lut_size)
|
|
{
|
|
DRWPass *pass = DRW_pass_create(__func__, DRW_STATE_WRITE_COLOR);
|
|
DRWShadingGroup *grp = DRW_shgroup_create(EEVEE_shaders_ggx_lut_sh_get(), pass);
|
|
DRW_shgroup_uniform_float_copy(grp, "sampleCount", 64.0f); /* Actual sample count is squared. */
|
|
DRW_shgroup_call_procedural_triangles(grp, NULL, 1);
|
|
|
|
GPUTexture *tex = DRW_texture_create_2d(lut_size, lut_size, GPU_RG16F, 0, NULL);
|
|
GPUFrameBuffer *fb = NULL;
|
|
GPU_framebuffer_ensure_config(&fb,
|
|
{
|
|
GPU_ATTACHMENT_NONE,
|
|
GPU_ATTACHMENT_TEXTURE(tex),
|
|
});
|
|
GPU_framebuffer_bind(fb);
|
|
DRW_draw_pass(pass);
|
|
GPU_FRAMEBUFFER_FREE_SAFE(fb);
|
|
|
|
float *data = GPU_texture_read(tex, GPU_DATA_FLOAT, 0);
|
|
GPU_texture_free(tex);
|
|
#if DO_FILE_OUTPUT
|
|
/* Content is to be put inside eevee_lut.c */
|
|
FILE *f = BLI_fopen("bsdf_split_sum_ggx.h", "w");
|
|
fprintf(f, "const float bsdf_split_sum_ggx[%d * %d * 2] = {", lut_size, lut_size);
|
|
for (int i = 0; i < lut_size * lut_size * 2;) {
|
|
fprintf(f, "\n ");
|
|
for (int j = 0; j < 4; j++, i += 2) {
|
|
fprintf(f, "%ff, %ff, ", data[i], data[i + 1]);
|
|
}
|
|
}
|
|
fprintf(f, "\n};\n");
|
|
fclose(f);
|
|
#endif
|
|
|
|
return data;
|
|
}
|
|
|
|
float *EEVEE_lut_update_ggx_btdf(int lut_size, int lut_depth)
|
|
{
|
|
float roughness;
|
|
DRWPass *pass = DRW_pass_create(__func__, DRW_STATE_WRITE_COLOR);
|
|
DRWShadingGroup *grp = DRW_shgroup_create(EEVEE_shaders_ggx_refraction_lut_sh_get(), pass);
|
|
DRW_shgroup_uniform_float_copy(grp, "sampleCount", 64.0f); /* Actual sample count is squared. */
|
|
DRW_shgroup_uniform_float(grp, "z", &roughness, 1);
|
|
DRW_shgroup_call_procedural_triangles(grp, NULL, 1);
|
|
|
|
GPUTexture *tex = DRW_texture_create_2d_array(lut_size, lut_size, lut_depth, GPU_RG16F, 0, NULL);
|
|
GPUFrameBuffer *fb = NULL;
|
|
for (int i = 0; i < lut_depth; i++) {
|
|
GPU_framebuffer_ensure_config(&fb,
|
|
{
|
|
GPU_ATTACHMENT_NONE,
|
|
GPU_ATTACHMENT_TEXTURE_LAYER(tex, i),
|
|
});
|
|
GPU_framebuffer_bind(fb);
|
|
roughness = i / (lut_depth - 1.0f);
|
|
DRW_draw_pass(pass);
|
|
}
|
|
|
|
GPU_FRAMEBUFFER_FREE_SAFE(fb);
|
|
|
|
float *data = GPU_texture_read(tex, GPU_DATA_FLOAT, 0);
|
|
GPU_texture_free(tex);
|
|
|
|
#if DO_FILE_OUTPUT
|
|
/* Content is to be put inside eevee_lut.c. Don't forget to format the output. */
|
|
FILE *f = BLI_fopen("btdf_split_sum_ggx.h", "w");
|
|
fprintf(f, "const float btdf_split_sum_ggx[%d][%d * %d * 2] = {", lut_depth, lut_size, lut_size);
|
|
fprintf(f, "\n ");
|
|
int ofs = 0;
|
|
for (int d = 0; d < lut_depth; d++) {
|
|
fprintf(f, "{\n");
|
|
for (int i = 0; i < lut_size * lut_size * 2;) {
|
|
for (int j = 0; j < 4; j++, i += 2, ofs += 2) {
|
|
fprintf(f, "%ff, %ff, ", data[ofs], data[ofs + 1]);
|
|
}
|
|
fprintf(f, "\n ");
|
|
}
|
|
fprintf(f, "},\n");
|
|
}
|
|
fprintf(f, "};\n");
|
|
fclose(f);
|
|
#endif
|
|
|
|
return data;
|
|
}
|