diff options
Diffstat (limited to 'ray.c')
| -rw-r--r-- | ray.c | 72 |
1 files changed, 62 insertions, 10 deletions
@@ -9,6 +9,8 @@ #define PI 3.14159265359 +int ray_trace_recur(space_t *s, color_t *dest, ray_t *ray, unsigned hop, COORD_T scale, void *seed); + // https://en.wikipedia.org/wiki/Line%E2%80%93sphere_intersection // http://viclw17.github.io/2018/07/16/raytracing-ray-sphere-intersection/ // https://www.scratchapixel.com/lessons/3d-basic-rendering/minimal-ray-tracer-rendering-simple-shapes/ray-sphere-intersection @@ -212,7 +214,7 @@ static void contribution_from_arealight(space_t *s, color_t *dest, object_t *o, // Do the same monte carlo as with environment but the starting point is the center of the circle. // And the result is a point on the circle - for (int i = 0; i < 16; i++) { + for (int i = 0; i < s->gfx->arealight_samples; i++) { // Do the monte carlo random distribution thing from the article COORD_T r1 = ray_rand(seed); @@ -245,7 +247,7 @@ static void contribution_from_arealight(space_t *s, color_t *dest, object_t *o, } // Device by pdf - color_scale(&c, &c, ((COORD_T) 1 / 16) * (2 * PI)); + color_scale(&c, &c, ((COORD_T) 1 / s->gfx->arealight_samples) * (2 * PI)); color_add(dest, dest, &c); @@ -281,6 +283,9 @@ static void direct_light(space_t *s, color_t *dest, object_t *o, vector_t *N, ve // https://www.scratchapixel.com/lessons/3d-basic-rendering/global-illumination-path-tracing/global-illumination-path-tracing-practical-implementation static void env_light(space_t *s, color_t *dest, object_t *o, vector_t *N, vector_t *point, void *seed) { + if (s->gfx->envlight_samples == 0) { + return; + } csystem_t cs; csystem_init(&cs, N); @@ -292,7 +297,7 @@ static void env_light(space_t *s, color_t *dest, object_t *o, vector_t *N, vecto color_t acc; color_set(&acc, 0, 0, 0); - for (unsigned i = 0; i < s->env_samples; i++) { + for (unsigned i = 0; i < s->gfx->envlight_samples; i++) { COORD_T r1 = ray_rand(seed); // Calculate the random direction vector @@ -318,13 +323,58 @@ static void env_light(space_t *s, color_t *dest, object_t *o, vector_t *N, vecto } // Devide by number of samples and pdf - color_scale(&acc, &acc, ((COORD_T) 1/ s->env_samples) * (2 * PI)); + color_scale(&acc, &acc, ((COORD_T) 1/ s->gfx->envlight_samples) * (2 * PI)); // Add to dest color_add(dest, dest, &acc); } +// https://www.scratchapixel.com/lessons/3d-basic-rendering/global-illumination-path-tracing/global-illumination-path-tracing-practical-implementation +static void global_light(space_t *s, color_t *dest, object_t *o, vector_t *N, vector_t *point, unsigned hop, void *seed) +{ + if (s->gfx->globallight_samples == 0) { + return; + } + + // Init hemisphere translation + csystem_t cs; + csystem_init(&cs, N); + + // Prepare ray + ray_t r; + r.start = point; + + // Value for accumilating colors + color_t acc; + color_set(&acc, 0, 0, 0); + + for (unsigned i = 0; i < s->gfx->globallight_samples; i++) { + COORD_T r1 = ray_rand(seed); + + // Calculate the random direction vector + vector_t randdir; + csystem_hemisphere_random(&cs, r1, ray_rand(seed), &randdir); + + // Convert to world cordinates using the calculated N vectors. + csystem_calc_real(&cs, &randdir, &randdir); + + // Check the direction for obstacles + r.direction = &randdir; + + // Cast ray in direction if we have more hops + if (hop < s->gfx->depth) { + ray_trace_recur(s, &acc, &r, hop+1, r1, seed); + } + } + + // Devide by number of samples and pdf + color_scale(&acc, &acc, ((COORD_T) 1/ s->gfx->globallight_samples) * (2 * PI)); + + // Add to dest + color_add(dest, dest, &acc); +} + int ray_trace_recur(space_t *s, color_t *dest, ray_t *ray, unsigned hop, COORD_T scale, void *seed) { COORD_T dist; @@ -359,10 +409,12 @@ int ray_trace_recur(space_t *s, color_t *dest, ray_t *ray, unsigned hop, COORD_T } // Calculate environmental light - if (s->env_samples) { + if (s->env_enabled) { env_light(s, &c, o, &N, r.start, seed); } + global_light(s, &c, o, &N, r.start, hop, seed); + // Calculate reflection vector if (hop < 10 && o->m->reflective > ZERO_APROX) { vector_scale(r.direction, &N, 2 * vector_dot(ray->direction, &N)); @@ -383,7 +435,7 @@ exit: return 0; } -void ray_trace(space_t *s, unsigned int x, unsigned int y, unsigned samples, color_t *c, void *seed) +void ray_trace(space_t *s, unsigned int x, unsigned int y, color_t *c, void *seed) { // Init return color. Will be accumilated with all the detected light. color_set(c, 0, 0, 0); @@ -397,13 +449,13 @@ void ray_trace(space_t *s, unsigned int x, unsigned int y, unsigned samples, col // Multiple samples for antialias // TODO better distribution of antialias probes - for (int i = 0; i < samples; i++) { + for (int i = 0; i < s->gfx->antialias_samples; i++) { color_t ctmp; color_set(&ctmp, 0, 0, 0); //memset(&ctmp, 0, sizeof(color_t)); // Multiple samples inside same pixel - COORD_T tmp = (COORD_T) i/ (COORD_T) samples; + COORD_T tmp = (COORD_T) i/ (COORD_T) s->gfx->antialias_samples; viewpoint_ray(&s->view, r.direction, x + tmp, y + tmp); // Run the recursive ray trace @@ -415,9 +467,9 @@ void ray_trace(space_t *s, unsigned int x, unsigned int y, unsigned samples, col } // Take the median - if (samples > 1) { + if (s->gfx->antialias_samples > 1) { // Same as deviding by samples - color_scale(c, c, 1.0/ (COORD_T) samples); + color_scale(c, c, 1.0/ (COORD_T) s->gfx->antialias_samples); } // Add ambient |