diff options
Diffstat (limited to 'intern/cycles/kernel/kernel_random.h')
| -rw-r--r-- | intern/cycles/kernel/kernel_random.h | 261 |
1 files changed, 72 insertions, 189 deletions
diff --git a/intern/cycles/kernel/kernel_random.h b/intern/cycles/kernel/kernel_random.h index e8a912ccc0b..221d92f5de1 100644 --- a/intern/cycles/kernel/kernel_random.h +++ b/intern/cycles/kernel/kernel_random.h @@ -18,6 +18,16 @@ CCL_NAMESPACE_BEGIN +/* Pseudo random numbers, uncomment this for debugging correlations. Only run + * this single threaded on a CPU for repeatable resutls. */ +//#define __DEBUG_CORRELATION__ + + +/* High Dimensional Sobol. + * + * Multidimensional sobol with generator matrices. Dimension 0 and 1 are equal + * to classic Van der Corput and Sobol sequences. */ + #ifdef __SOBOL__ /* Skip initial numbers that are not as well distributed, especially the @@ -26,47 +36,6 @@ CCL_NAMESPACE_BEGIN */ #define SOBOL_SKIP 64 -/* High Dimensional Sobol. */ - -/* Van der Corput radical inverse. */ -ccl_device uint van_der_corput(uint bits) -{ - bits = (bits << 16) | (bits >> 16); - bits = ((bits & 0x00ff00ff) << 8) | ((bits & 0xff00ff00) >> 8); - bits = ((bits & 0x0f0f0f0f) << 4) | ((bits & 0xf0f0f0f0) >> 4); - bits = ((bits & 0x33333333) << 2) | ((bits & 0xcccccccc) >> 2); - bits = ((bits & 0x55555555) << 1) | ((bits & 0xaaaaaaaa) >> 1); - return bits; -} - -/* Sobol radical inverse. */ -ccl_device uint sobol(uint i) -{ - uint r = 0; - for(uint v = 1U << 31; i; i >>= 1, v ^= v >> 1) { - if(i & 1) { - r ^= v; - } - } - return r; -} - -/* Inverse of sobol radical inverse. */ -ccl_device uint sobol_inverse(uint i) -{ - const uint msb = 1U << 31; - uint r = 0; - for(uint v = 1; i; i <<= 1, v ^= v << 1) { - if(i & msb) { - r ^= v; - } - } - return r; -} - -/* Multidimensional sobol with generator matrices - * dimension 0 and 1 are equal to van_der_corput() and sobol() respectively. - */ ccl_device uint sobol_dimension(KernelGlobals *kg, int index, int dimension) { uint result = 0; @@ -79,50 +48,31 @@ ccl_device uint sobol_dimension(KernelGlobals *kg, int index, int dimension) return result; } -/* Lookup index and x/y coordinate, assumes m is a power of two. */ -ccl_device uint sobol_lookup(const uint m, - const uint frame, - const uint ex, - const uint ey, - uint *x, uint *y) -{ - /* Shift is constant per frame. */ - const uint shift = frame << (m << 1); - const uint sobol_shift = sobol(shift); - /* Van der Corput is its own inverse. */ - const uint lower = van_der_corput(ex << (32 - m)); - /* Need to compensate for ey difference and shift. */ - const uint sobol_lower = sobol(lower); - const uint mask = ~-(1 << m) << (32 - m); /* Only m upper bits. */ - const uint delta = ((ey << (32 - m)) ^ sobol_lower ^ sobol_shift) & mask; - /* Only use m upper bits for the index (m is a power of two). */ - const uint sobol_result = delta | (delta >> m); - const uint upper = sobol_inverse(sobol_result); - const uint index = shift | upper | lower; - *x = van_der_corput(index); - *y = sobol_shift ^ sobol_result ^ sobol_lower; - return index; -} +#endif /* __SOBOL__ */ + ccl_device_forceinline float path_rng_1D(KernelGlobals *kg, - RNG *rng, + uint rng_hash, int sample, int num_samples, int dimension) { +#ifdef __DEBUG_CORRELATION__ + return (float)drand48(); +#endif + #ifdef __CMJ__ - if(kernel_data.integrator.sampling_pattern == SAMPLING_PATTERN_CMJ) { +# ifdef __SOBOL__ + if(kernel_data.integrator.sampling_pattern == SAMPLING_PATTERN_CMJ) +# endif + { /* Correlated multi-jitter. */ - int p = *rng + dimension; + int p = rng_hash + dimension; return cmj_sample_1D(sample, num_samples, p); } #endif -#ifdef __SOBOL_FULL_SCREEN__ - uint result = sobol_dimension(kg, *rng, dimension); - float r = (float)result * (1.0f/(float)0xFFFFFFFF); - return r; -#else - /* Compute sobol sequence value using direction vectors. */ +#ifdef __SOBOL__ + /* Sobol sequence value using direction vectors. */ uint result = sobol_dimension(kg, sample + SOBOL_SKIP, dimension); float r = (float)result * (1.0f/(float)0xFFFFFFFF); @@ -132,7 +82,7 @@ ccl_device_forceinline float path_rng_1D(KernelGlobals *kg, /* Hash rng with dimension to solve correlation issues. * See T38710, T50116. */ - RNG tmp_rng = cmj_hash_simple(dimension, *rng); + uint tmp_rng = cmj_hash_simple(dimension, rng_hash); shift = tmp_rng * (1.0f/(float)0xFFFFFFFF); return r + shift - floorf(r + shift); @@ -140,128 +90,60 @@ ccl_device_forceinline float path_rng_1D(KernelGlobals *kg, } ccl_device_forceinline void path_rng_2D(KernelGlobals *kg, - RNG *rng, + uint rng_hash, int sample, int num_samples, int dimension, float *fx, float *fy) { +#ifdef __DEBUG_CORRELATION__ + *fx = (float)drand48(); + *fy = (float)drand48(); + return; +#endif + #ifdef __CMJ__ - if(kernel_data.integrator.sampling_pattern == SAMPLING_PATTERN_CMJ) { +# ifdef __SOBOL__ + if(kernel_data.integrator.sampling_pattern == SAMPLING_PATTERN_CMJ) +# endif + { /* Correlated multi-jitter. */ - int p = *rng + dimension; + int p = rng_hash + dimension; cmj_sample_2D(sample, num_samples, p, fx, fy); + return; } - else #endif - { - /* Sobol. */ - *fx = path_rng_1D(kg, rng, sample, num_samples, dimension); - *fy = path_rng_1D(kg, rng, sample, num_samples, dimension + 1); - } + +#ifdef __SOBOL__ + /* Sobol. */ + *fx = path_rng_1D(kg, rng_hash, sample, num_samples, dimension); + *fy = path_rng_1D(kg, rng_hash, sample, num_samples, dimension + 1); +#endif } ccl_device_inline void path_rng_init(KernelGlobals *kg, ccl_global uint *rng_state, int sample, int num_samples, - RNG *rng, + uint *rng_hash, int x, int y, float *fx, float *fy) { -#ifdef __SOBOL_FULL_SCREEN__ - uint px, py; - uint bits = 16; /* limits us to 65536x65536 and 65536 samples */ - uint size = 1 << bits; - uint frame = sample; - - *rng = sobol_lookup(bits, frame, x, y, &px, &py); - - *rng ^= kernel_data.integrator.seed; - - if(sample == 0) { - *fx = 0.5f; - *fy = 0.5f; - } - else { - *fx = size * (float)px * (1.0f/(float)0xFFFFFFFF) - x; - *fy = size * (float)py * (1.0f/(float)0xFFFFFFFF) - y; - } -#else - *rng = *rng_state; - - *rng ^= kernel_data.integrator.seed; - - if(sample == 0) { - *fx = 0.5f; - *fy = 0.5f; - } - else { - path_rng_2D(kg, rng, sample, num_samples, PRNG_FILTER_U, fx, fy); - } -#endif -} - -ccl_device void path_rng_end(KernelGlobals *kg, - ccl_global uint *rng_state, - RNG rng) -{ - /* nothing to do */ -} - -#else /* __SOBOL__ */ - -/* Linear Congruential Generator */ - -ccl_device_forceinline float path_rng_1D(KernelGlobals *kg, - RNG *rng, - int sample, int num_samples, - int dimension) -{ - /* implicit mod 2^32 */ - *rng = (1103515245*(*rng) + 12345); - return (float)*rng * (1.0f/(float)0xFFFFFFFF); -} - -ccl_device_inline void path_rng_2D(KernelGlobals *kg, - RNG *rng, - int sample, int num_samples, - int dimension, - float *fx, float *fy) -{ - *fx = path_rng_1D(kg, rng, sample, num_samples, dimension); - *fy = path_rng_1D(kg, rng, sample, num_samples, dimension + 1); -} - -ccl_device void path_rng_init(KernelGlobals *kg, - ccl_global uint *rng_state, - int sample, int num_samples, - RNG *rng, - int x, int y, - float *fx, float *fy) -{ /* load state */ - *rng = *rng_state; + *rng_hash = *rng_state; + *rng_hash ^= kernel_data.integrator.seed; - *rng ^= kernel_data.integrator.seed; +#ifdef __DEBUG_CORRELATION__ + srand48(*rng_hash + sample); +#endif if(sample == 0) { *fx = 0.5f; *fy = 0.5f; } else { - path_rng_2D(kg, rng, sample, num_samples, PRNG_FILTER_U, fx, fy); + path_rng_2D(kg, *rng_hash, sample, num_samples, PRNG_FILTER_U, fx, fy); } } -ccl_device void path_rng_end(KernelGlobals *kg, - ccl_global uint *rng_state, - RNG rng) -{ - /* store state for next sample */ - *rng_state = rng; -} - -#endif /* __SOBOL__ */ - /* Linear Congruential Generator */ ccl_device uint lcg_step_uint(uint *rng) @@ -295,19 +177,17 @@ ccl_device uint lcg_init(uint seed) */ ccl_device_inline float path_state_rng_1D(KernelGlobals *kg, - RNG *rng, const ccl_addr_space PathState *state, int dimension) { return path_rng_1D(kg, - rng, + state->rng_hash, state->sample, state->num_samples, state->rng_offset + dimension); } ccl_device_inline float path_state_rng_1D_for_decision( KernelGlobals *kg, - RNG *rng, const ccl_addr_space PathState *state, int dimension) { @@ -320,19 +200,18 @@ ccl_device_inline float path_state_rng_1D_for_decision( * the same decision. */ const int rng_offset = state->rng_offset + state->transparent_bounce * PRNG_BOUNCE_NUM; return path_rng_1D(kg, - rng, + state->rng_hash, state->sample, state->num_samples, rng_offset + dimension); } ccl_device_inline void path_state_rng_2D(KernelGlobals *kg, - RNG *rng, const ccl_addr_space PathState *state, int dimension, float *fx, float *fy) { path_rng_2D(kg, - rng, + state->rng_hash, state->sample, state->num_samples, state->rng_offset + dimension, fx, fy); @@ -340,14 +219,14 @@ ccl_device_inline void path_state_rng_2D(KernelGlobals *kg, ccl_device_inline float path_branched_rng_1D( KernelGlobals *kg, - RNG *rng, + uint rng_hash, const ccl_addr_space PathState *state, int branch, int num_branches, int dimension) { return path_rng_1D(kg, - rng, + rng_hash, state->sample * num_branches + branch, state->num_samples * num_branches, state->rng_offset + dimension); @@ -355,7 +234,7 @@ ccl_device_inline float path_branched_rng_1D( ccl_device_inline float path_branched_rng_1D_for_decision( KernelGlobals *kg, - RNG *rng, + uint rng_hash, const ccl_addr_space PathState *state, int branch, int num_branches, @@ -363,7 +242,7 @@ ccl_device_inline float path_branched_rng_1D_for_decision( { const int rng_offset = state->rng_offset + state->transparent_bounce * PRNG_BOUNCE_NUM; return path_rng_1D(kg, - rng, + rng_hash, state->sample * num_branches + branch, state->num_samples * num_branches, rng_offset + dimension); @@ -371,7 +250,7 @@ ccl_device_inline float path_branched_rng_1D_for_decision( ccl_device_inline void path_branched_rng_2D( KernelGlobals *kg, - RNG *rng, + uint rng_hash, const ccl_addr_space PathState *state, int branch, int num_branches, @@ -379,7 +258,7 @@ ccl_device_inline void path_branched_rng_2D( float *fx, float *fy) { path_rng_2D(kg, - rng, + rng_hash, state->sample * num_branches + branch, state->num_samples * num_branches, state->rng_offset + dimension, @@ -391,25 +270,24 @@ ccl_device_inline void path_branched_rng_2D( */ ccl_device_inline float path_state_rng_light_termination( KernelGlobals *kg, - RNG *rng, const ccl_addr_space PathState *state) { if(kernel_data.integrator.light_inv_rr_threshold > 0.0f) { - return path_state_rng_1D_for_decision(kg, rng, state, PRNG_LIGHT_TERMINATE); + return path_state_rng_1D_for_decision(kg, state, PRNG_LIGHT_TERMINATE); } return 0.0f; } ccl_device_inline float path_branched_rng_light_termination( KernelGlobals *kg, - RNG *rng, + uint rng_hash, const ccl_addr_space PathState *state, int branch, int num_branches) { if(kernel_data.integrator.light_inv_rr_threshold > 0.0f) { return path_branched_rng_1D_for_decision(kg, - rng, + rng_hash, state, branch, num_branches, @@ -429,14 +307,19 @@ ccl_device_inline void path_state_branch(ccl_addr_space PathState *state, state->num_samples = state->num_samples*num_branches; } -ccl_device_inline uint lcg_state_init(RNG *rng, - int rng_offset, - int sample, +ccl_device_inline uint lcg_state_init(PathState *state, uint scramble) { - return lcg_init(*rng + rng_offset + sample*scramble); + return lcg_init(state->rng_hash + state->rng_offset + state->sample*scramble); } +ccl_device_inline uint lcg_state_init_addrspace(ccl_addr_space PathState *state, + uint scramble) +{ + return lcg_init(state->rng_hash + state->rng_offset + state->sample*scramble); +} + + ccl_device float lcg_step_float_addrspace(ccl_addr_space uint *rng) { /* Implicit mod 2^32 */ |