star-mc

Parallel estimation of Monte Carlo integrators
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test_smc_light_path.c (13258B)


      1 /* Copyright (C) 2015-2018, 2021-2023 |Méso|Star> (contact@meso-star.com)
      2  *
      3  * This program is free software: you can redistribute it and/or modify
      4  * it under the terms of the GNU General Public License as published by
      5  * the Free Software Foundation, either version 3 of the License, or
      6  * (at your option) any later version.
      7  *
      8  * This program is distributed in the hope that it will be useful,
      9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
     11  * GNU General Public License for more details.
     12  *
     13  * You should have received a copy of the GNU General Public License
     14  * along with this program. If not, see <http://www.gnu.org/licenses/>. */
     15 
     16 #include "smc.h"
     17 #include "test_smc_utils.h"
     18 
     19 #include <star/s3d.h>
     20 #include <star/ssp.h>
     21 
     22 #include <rsys/float2.h>
     23 #include <rsys/float3.h>
     24 #include <rsys/image.h>
     25 #include <rsys/math.h>
     26 #include <rsys/mem_allocator.h>
     27 
     28 #define IMG_WIDTH 640
     29 #define IMG_HEIGHT 480
     30 #define LIGHT_PATH_DEPTH 16
     31 #define ALBEDO 0.6f
     32 #define EPSILON 1.e-1f
     33 #define GAMMA 2.2
     34 
     35 struct cbox_desc{
     36   const float* vertices;
     37   const unsigned* indices;
     38 };
     39 
     40 /*******************************************************************************
     41  * Box walls data
     42  ******************************************************************************/
     43 static const float cbox_walls[] = {
     44   552.f, 0.f,   0.f,
     45   0.f,   0.f,   0.f,
     46   0.f,   559.f, 0.f,
     47   552.f, 559.f, 0.f,
     48   552.f, 0.f,   548.f,
     49   0.f,   0.f,   548.f,
     50   0.f,   559.f, 548.f,
     51   552.f, 559.f, 548.f
     52 };
     53 
     54 const unsigned cbox_walls_ids[] = {
     55   0, 1, 2, 2, 3, 0, /* Bottom */
     56   4, 5, 6, 6, 7, 4, /* Top */
     57   1, 2, 6, 6, 5, 1, /* Left */
     58   0, 3, 7, 7, 4, 0, /* Right */
     59   2, 3, 7, 7, 6, 2  /* Back */
     60 };
     61 
     62 static const unsigned cbox_walls_ntris = sizeof(cbox_walls_ids)/(3*sizeof(unsigned));
     63 static const unsigned cbox_walls_nverts = sizeof(cbox_walls)/(3*sizeof(float));
     64 static struct cbox_desc cbox_walls_desc = { cbox_walls, cbox_walls_ids };
     65 
     66 /*******************************************************************************
     67  * Short/tall blocks data
     68  ******************************************************************************/
     69 static const float cbox_short_block[] = {
     70   130.f, 65.f,  0.f,
     71   82.f,  225.f, 0.f,
     72   240.f, 272.f, 0.f,
     73   290.f, 114.f, 0.f,
     74   130.f, 65.f,  165.f,
     75   82.f,  225.f, 165.f,
     76   240.f, 272.f, 165.f,
     77   290.f, 114.f, 165.f
     78 };
     79 
     80 static const float cbox_tall_block[] = {
     81   423.0f, 247.0f, 0.f,
     82   265.0f, 296.0f, 0.f,
     83   314.0f, 456.0f, 0.f,
     84   472.0f, 406.0f, 0.f,
     85   423.0f, 247.0f, 330.f,
     86   265.0f, 296.0f, 330.f,
     87   314.0f, 456.0f, 330.f,
     88   472.0f, 406.0f, 330.f
     89 };
     90 
     91 static const unsigned cbox_block_ids[] = {
     92   4, 5, 6, 6, 7, 4,
     93   1, 2, 6, 6, 5, 1,
     94   0, 3, 7, 7, 4, 0,
     95   2, 3, 7, 7, 6, 2,
     96   0, 1, 5, 5, 4, 0
     97 };
     98 
     99 static const unsigned cbox_block_ntris = sizeof(cbox_block_ids)/(3*sizeof(unsigned));
    100 
    101 static const unsigned cbox_short_block_nverts =
    102   sizeof(cbox_short_block)/(3*sizeof(float));
    103 static struct cbox_desc cbox_short_block_desc =
    104   { cbox_short_block, cbox_block_ids };
    105 
    106 static const unsigned cbox_tall_block_nverts =
    107   sizeof(cbox_tall_block)/(3*sizeof(float));
    108 static struct cbox_desc cbox_tall_block_desc =
    109   { cbox_tall_block, cbox_block_ids };
    110 
    111 /*******************************************************************************
    112  * Cornell box callbacks
    113  ******************************************************************************/
    114 static INLINE void
    115 cbox_get_ids(const unsigned itri, unsigned ids[3], void* data)
    116 {
    117   const unsigned id = itri * 3;
    118   struct cbox_desc* desc = data;
    119   CHK(desc != NULL);
    120   ids[0] = desc->indices[id + 0];
    121   ids[1] = desc->indices[id + 1];
    122   ids[2] = desc->indices[id + 2];
    123 }
    124 
    125 static INLINE void
    126 cbox_get_position(const unsigned ivert, float position[3], void* data)
    127 {
    128   struct cbox_desc* desc = data;
    129   CHK(desc != NULL);
    130   position[0] = desc->vertices[ivert*3 + 0];
    131   position[1] = desc->vertices[ivert*3 + 1];
    132   position[2] = desc->vertices[ivert*3 + 2];
    133 }
    134 
    135 /*******************************************************************************
    136  * Camera
    137  ******************************************************************************/
    138 struct camera {
    139   float pos[3];
    140   float x[3], y[3], z[3]; /* Basis */
    141 };
    142 
    143 static void
    144 camera_init(struct camera* cam)
    145 {
    146   const float pos[3] = { 178.f, -1000.f, 273.f };
    147   const float tgt[3] = { 178.f, 0.f, 273.f };
    148   const float up[3] = { 0.f, 0.f, 1.f };
    149   const float proj_ratio = (float)IMG_WIDTH/(float)IMG_HEIGHT;
    150   const float fov_x = (float)PI * 0.25f;
    151   float f = 0.f;
    152   ASSERT(cam);
    153 
    154   f3_set(cam->pos, pos);
    155   f = f3_normalize(cam->z, f3_sub(cam->z, tgt, pos)); CHK(f != 0);
    156   f = f3_normalize(cam->x, f3_cross(cam->x, cam->z, up)); CHK(f != 0);
    157   f = f3_normalize(cam->y, f3_cross(cam->y, cam->z, cam->x)); CHK(f != 0);
    158   f3_divf(cam->z, cam->z, (float)tan(fov_x*0.5f));
    159   f3_divf(cam->y, cam->y, proj_ratio);
    160 }
    161 
    162 static void
    163 camera_ray
    164   (const struct camera* cam,
    165    const float pixel[2],
    166    float org[3],
    167    float dir[3])
    168 {
    169   float x[3], y[3], f;
    170   ASSERT(cam && pixel && org && dir);
    171 
    172   f3_mulf(x, cam->x, pixel[0]*2.f - 1.f);
    173   f3_mulf(y, cam->y, pixel[1]*2.f - 1.f);
    174   f3_add(dir, f3_add(dir, x, y), cam->z);
    175   f = f3_normalize(dir, dir); CHK(f != 0);
    176   f3_set(org, cam->pos);
    177 }
    178 
    179 /*******************************************************************************
    180  * Integrator
    181  ******************************************************************************/
    182 struct integrator_context {
    183   struct s3d_scene_view* view;
    184   struct camera* cam;
    185   float pixel_size[2]; /* Normalized pixel size */
    186   size_t ipixel[2]; /* Image space pixel coordinates */
    187 };
    188 
    189 static float
    190 direct_lighting
    191   (struct s3d_scene_view* view, const float pos[3], const float N[3])
    192 {
    193   const float light_pos[3] = { 200.f, 200.f, 400.f };
    194   const float flux = 60.0; /* Radiant flux in watt */
    195   const float intensity = (float)(flux/(4.0*PI)); /*Radiant intensity in W/sr*/
    196   struct s3d_hit hit;
    197   float len;
    198   float wi[3];
    199   float range[2];
    200 
    201   CHK(view != NULL);
    202   CHK(pos != NULL);
    203   CHK(N != NULL);
    204   CHK(f3_is_normalized(N) == 1);
    205 
    206   f3_sub(wi, light_pos, pos);
    207   len = f3_normalize(wi, wi);
    208 
    209   /* Trace shadow ray */
    210   range[0] = EPSILON;
    211   range[1] = len;
    212   CHK(s3d_scene_view_trace_ray(view, pos, wi, range, NULL, &hit) == RES_OK);
    213   if(!S3D_HIT_NONE(&hit)) return 0.f; /* Light is occluded */
    214 
    215   len *= 0.01f; /* Transform len from centimer to meter */
    216   return
    217     intensity / (len*len)  /* radiance in W/(sr.m^2) */
    218   * (float)(ALBEDO / PI) /* BRDF */
    219   * f3_dot(wi, N); /* cos(wi,N) */
    220 }
    221 
    222 static float
    223 skydome_lighting(const float wi[3])
    224 {
    225   const float ground_irradiance = 0.01f;
    226   const float sky_irradiance = 12.0f;
    227   float u;
    228 
    229   CHK(wi != NULL);
    230   u = CLAMP(wi[2], 0.f, 0.05f) * 1.f;
    231   return u * sky_irradiance + (1.f - u) * ground_irradiance;
    232 }
    233 
    234 static res_T
    235 light_path_integrator
    236   (void* value,
    237    struct ssp_rng* rng,
    238    const unsigned ithread,
    239    const uint64_t irealisation,
    240    void* data)
    241 {
    242   struct integrator_context* ctx = data;
    243   float pix_lower[2], pix_upper[2]; /* Pixel AABB */
    244   float pix_samp[2]; /* Pixel sample */
    245   float ray_org[3], ray_dir[3], ray_range[2];
    246   float L = 0.f;
    247   float throughput = 1.f;
    248   int idepth;
    249 
    250   (void)ithread, (void)irealisation;
    251 
    252   CHK(value != NULL);
    253   CHK(rng != NULL);
    254   CHK(data != NULL);
    255 
    256   /* Compute the pixel bound */
    257   pix_lower[0] = (float)ctx->ipixel[0] / (float)IMG_WIDTH;
    258   pix_lower[1] = (float)ctx->ipixel[1] / (float)IMG_HEIGHT;
    259   f2_add(pix_upper, pix_lower, ctx->pixel_size);
    260 
    261   /* Randomly sample the pixel quad */
    262   pix_samp[0] = (float)ssp_rng_uniform_double(rng, pix_lower[0], pix_upper[0]);
    263   pix_samp[1] = (float)ssp_rng_uniform_double(rng, pix_lower[1], pix_upper[1]);
    264 
    265   /* Build a camera ray */
    266   camera_ray(ctx->cam, pix_samp, ray_org, ray_dir);
    267   ray_range[0] = 0.f;
    268   ray_range[1] = FLT_MAX;
    269 
    270   FOR_EACH(idepth, 0, LIGHT_PATH_DEPTH) {
    271     struct s3d_hit hit = S3D_HIT_NULL;
    272     float cos_theta;
    273     float pdf;
    274     float pos[3];
    275     float N[3] = {0, 0, 0};
    276 
    277     CHK(s3d_scene_view_trace_ray
    278       (ctx->view, ray_org, ray_dir, ray_range, NULL, &hit) == RES_OK);
    279 
    280     if(S3D_HIT_NONE(&hit)) { /* Skydome lighting */
    281       L += throughput * skydome_lighting(ray_dir);
    282       break;
    283     }
    284 
    285     f3_normalize(N, hit.normal);
    286     cos_theta = f3_dot(N, ray_dir);
    287     if(cos_theta >= 0.f) f3_minus(N, N);
    288     f3_add(pos, f3_mulf(pos, ray_dir, hit.distance), ray_org);
    289 
    290     /* Direct lighting */
    291     L += throughput * direct_lighting(ctx->view, pos, N);
    292 
    293     /* New ray */
    294     ssp_ran_hemisphere_cos_float(rng, N, ray_dir, &pdf);
    295     cos_theta = f3_dot(N, ray_dir);
    296     f3_set(ray_org, pos);
    297     ray_range[0] = EPSILON;
    298     throughput *= (float)(ALBEDO / PI) / pdf * cos_theta;
    299   }
    300   *(float*)value = L;
    301   return RES_OK;
    302 }
    303 
    304 /*******************************************************************************
    305  * Application
    306  ******************************************************************************/
    307 int
    308 main(int argc, char** argv)
    309 {
    310   struct mem_allocator allocator;
    311   struct image img;
    312   FILE* fp = NULL;
    313   struct integrator_context* contexts;
    314   struct s3d_device* dev;
    315   struct s3d_scene* scn;
    316   struct s3d_scene_view* view;
    317   struct s3d_shape* shape;
    318   struct s3d_vertex_data attrib;
    319   struct smc_device_create_args args = SMC_DEVICE_CREATE_ARGS_DEFAULT;
    320   struct smc_device* smc;
    321   struct smc_integrator integrator = SMC_INTEGRATOR_NULL;
    322   struct smc_estimator** estimators;
    323   struct camera cam;
    324   size_t ix, iy;
    325   float pos[3];
    326   (void)argc, (void)argv;
    327 
    328   mem_init_proxy_allocator(&allocator, &mem_default_allocator);
    329 
    330   CHK(image_init(&allocator, &img) == RES_OK);
    331   CHK(image_setup
    332     (&img, IMG_WIDTH, IMG_HEIGHT, 3*IMG_WIDTH, IMAGE_RGB8, NULL) == RES_OK);
    333 
    334   CHK(s3d_device_create(NULL, &allocator, 0, &dev) == RES_OK);
    335   CHK(s3d_scene_create(dev, &scn) == RES_OK);
    336 
    337   attrib.usage = S3D_POSITION;
    338   attrib.type = S3D_FLOAT3;
    339   attrib.get = cbox_get_position;
    340 
    341   CHK(s3d_shape_create_mesh(dev, &shape) == RES_OK);
    342   CHK(s3d_mesh_setup_indexed_vertices(shape, cbox_walls_ntris, cbox_get_ids,
    343     cbox_walls_nverts, &attrib, 1, &cbox_walls_desc) == RES_OK);
    344   CHK(s3d_scene_attach_shape(scn, shape) == RES_OK);
    345   CHK(s3d_shape_ref_put(shape) == RES_OK);
    346 
    347   CHK(s3d_shape_create_mesh(dev, &shape) == RES_OK);
    348   CHK(s3d_mesh_setup_indexed_vertices(shape, cbox_block_ntris, cbox_get_ids,
    349     cbox_short_block_nverts, &attrib, 1, &cbox_short_block_desc) == RES_OK);
    350   CHK(s3d_scene_attach_shape(scn, shape) == RES_OK);
    351   CHK(s3d_shape_ref_put(shape) == RES_OK);
    352 
    353   CHK(s3d_shape_create_mesh(dev, &shape) == RES_OK);
    354   CHK(s3d_mesh_setup_indexed_vertices(shape, cbox_block_ntris, cbox_get_ids,
    355     cbox_tall_block_nverts, &attrib, 1, &cbox_tall_block_desc) == RES_OK);
    356   CHK(s3d_scene_attach_shape(scn, shape) == RES_OK);
    357   CHK(s3d_shape_ref_put(shape) == RES_OK);
    358 
    359   CHK(s3d_scene_instantiate(scn, &shape) == RES_OK);
    360   CHK(s3d_scene_ref_put(scn) == RES_OK);
    361   CHK(s3d_instance_set_position(shape, f3(pos, -100.f, 0.f, -2.f)) == RES_OK);
    362 
    363   CHK(s3d_scene_create(dev, &scn) == RES_OK);
    364   CHK(s3d_scene_attach_shape(scn, shape) == RES_OK);
    365   CHK(s3d_shape_ref_put(shape) == RES_OK);
    366 
    367   CHK(s3d_scene_view_create(scn, S3D_TRACE, &view) == RES_OK);
    368 
    369   args.allocator = &allocator;
    370   args.verbose = 1;
    371   CHK(smc_device_create(&args, &smc) == RES_OK);
    372 
    373   integrator.integrand = light_path_integrator;
    374   integrator.type = &smc_float;
    375   integrator.max_realisations = 64;
    376 
    377   contexts = MEM_CALLOC
    378     (&allocator, IMG_WIDTH*IMG_HEIGHT, sizeof(struct integrator_context));
    379   CHK(contexts != NULL);
    380   estimators = MEM_CALLOC
    381     (&allocator, IMG_WIDTH*IMG_HEIGHT, sizeof(struct smc_estimator*));
    382   CHK(estimators != NULL);
    383 
    384   camera_init(&cam);
    385 
    386   FOR_EACH(iy, 0, IMG_HEIGHT) {
    387   FOR_EACH(ix, 0, IMG_WIDTH) {
    388     const size_t ictx = iy * IMG_WIDTH + ix;
    389     contexts[ictx].view = view;
    390     contexts[ictx].cam = &cam;
    391     contexts[ictx].pixel_size[0] = 1.f / (float)IMG_WIDTH;
    392     contexts[ictx].pixel_size[1] = 1.f / (float)IMG_HEIGHT;
    393     contexts[ictx].ipixel[0] = ix;
    394     contexts[ictx].ipixel[1] = iy;
    395   }}
    396 
    397   CHK(smc_solve_N(smc, &integrator, IMG_WIDTH * IMG_HEIGHT, contexts,
    398     sizeof(struct integrator_context), estimators) == RES_OK);
    399 
    400   FOR_EACH(iy, 0, IMG_HEIGHT) {
    401   FOR_EACH(ix, 0, IMG_WIDTH) {
    402     const size_t iestimator = (iy*IMG_WIDTH + ix);
    403     uint8_t* pix = (uint8_t*)(img.pixels + iy*img.pitch + ix*3/*RGB*/);
    404     struct smc_estimator_status status;
    405     float col;
    406     unsigned char colu;
    407 
    408     CHK(smc_estimator_get_status(estimators[iestimator], &status) == RES_OK);
    409     col = (float)pow(SMC_FLOAT(status.E), 1.0/GAMMA); /* Gamma correction */
    410     colu = (uint8_t)(CLAMP(col, 0.f, 1.f) * 255.f); /* Float to U8 */
    411     pix[0] = pix[1] = pix[2] = colu;
    412     CHK(smc_estimator_ref_put(estimators[iestimator]) == RES_OK);
    413   }}
    414 
    415   CHK(fp = fopen("image.ppm", "w"));
    416   image_write_ppm_stream(&img, 0, fp);
    417   CHK(fclose(fp) == 0);
    418 
    419   CHK(image_release(&img) == RES_OK);
    420   MEM_RM(&allocator, contexts);
    421   MEM_RM(&allocator, estimators);
    422 
    423   CHK(s3d_scene_view_ref_put(view) == RES_OK);
    424 
    425   CHK(s3d_device_ref_put(dev) == RES_OK);
    426   CHK(s3d_scene_ref_put(scn) == RES_OK);
    427   CHK(smc_device_ref_put(smc) == RES_OK);
    428 
    429   check_memory_allocator(&allocator);
    430   mem_shutdown_proxy_allocator(&allocator);
    431   CHK(mem_allocated_size() == 0);
    432   return 0;
    433 }