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/* SPDX-License-Identifier: Apache-2.0
* Copyright 2011-2022 Blender Foundation */
#pragma once
#include "kernel/camera/camera.h"
#include "kernel/film/accumulate.h"
#include "kernel/film/adaptive_sampling.h"
#include "kernel/integrator/path_state.h"
#include "kernel/sample/pattern.h"
#include "kernel/geom/geom.h"
CCL_NAMESPACE_BEGIN
/* This helps with AA but it's not the real solution as it does not AA the geometry
* but it's better than nothing, thus committed. */
ccl_device_inline float bake_clamp_mirror_repeat(float u, float max)
{
/* use mirror repeat (like opengl texture) so that if the barycentric
* coordinate goes past the end of the triangle it is not always clamped
* to the same value, gives ugly patterns */
u /= max;
float fu = floorf(u);
u = u - fu;
return ((((int)fu) & 1) ? 1.0f - u : u) * max;
}
/* Offset towards center of triangle to avoid ray-tracing precision issues. */
ccl_device const float2 bake_offset_towards_center(KernelGlobals kg,
const int prim,
const float u,
const float v)
{
float3 tri_verts[3];
triangle_vertices(kg, prim, tri_verts);
/* Empirically determined values, by no means perfect. */
const float position_offset = 1e-4f;
const float uv_offset = 1e-5f;
/* Offset position towards center, amount relative to absolute size of position coordinates. */
const float3 P = u * tri_verts[0] + v * tri_verts[1] + (1.0f - u - v) * tri_verts[2];
const float3 center = (tri_verts[0] + tri_verts[1] + tri_verts[2]) / 3.0f;
const float3 to_center = center - P;
const float3 offset_P = P + normalize(to_center) *
min(len(to_center), max(max3(fabs(P)), 1.0f) * position_offset);
/* Compute barycentric coordinates at new position. */
const float3 v1 = tri_verts[1] - tri_verts[0];
const float3 v2 = tri_verts[2] - tri_verts[0];
const float3 vP = offset_P - tri_verts[0];
const float d11 = dot(v1, v1);
const float d12 = dot(v1, v2);
const float d22 = dot(v2, v2);
const float dP1 = dot(vP, v1);
const float dP2 = dot(vP, v2);
const float denom = d11 * d22 - d12 * d12;
if (denom == 0.0f) {
return make_float2(0.0f, 0.0f);
}
const float offset_v = clamp((d22 * dP1 - d12 * dP2) / denom, uv_offset, 1.0f - uv_offset);
const float offset_w = clamp((d11 * dP2 - d12 * dP1) / denom, uv_offset, 1.0f - uv_offset);
const float offset_u = clamp(1.0f - offset_v - offset_w, uv_offset, 1.0f - uv_offset);
return make_float2(offset_u, offset_v);
}
/* Return false to indicate that this pixel is finished.
* Used by CPU implementation to not attempt to sample pixel for multiple samples once its known
* that the pixel did converge. */
ccl_device bool integrator_init_from_bake(KernelGlobals kg,
IntegratorState state,
ccl_global const KernelWorkTile *ccl_restrict tile,
ccl_global float *render_buffer,
const int x,
const int y,
const int scheduled_sample)
{
PROFILING_INIT(kg, PROFILING_RAY_SETUP);
/* Initialize path state to give basic buffer access and allow early outputs. */
path_state_init(state, tile, x, y);
/* Check whether the pixel has converged and should not be sampled anymore. */
if (!kernel_need_sample_pixel(kg, state, render_buffer)) {
return false;
}
/* Always count the sample, even if the camera sample will reject the ray. */
const int sample = kernel_accum_sample(
kg, state, render_buffer, scheduled_sample, tile->sample_offset);
/* Setup render buffers. */
const int index = INTEGRATOR_STATE(state, path, render_pixel_index);
const int pass_stride = kernel_data.film.pass_stride;
ccl_global float *buffer = render_buffer + index * pass_stride;
ccl_global float *primitive = buffer + kernel_data.film.pass_bake_primitive;
ccl_global float *differential = buffer + kernel_data.film.pass_bake_differential;
const int seed = __float_as_uint(primitive[0]);
int prim = __float_as_uint(primitive[1]);
if (prim == -1) {
/* Accumulate transparency for empty pixels. */
kernel_accum_transparent(kg, state, 0, 1.0f, buffer);
return false;
}
prim += kernel_data.bake.tri_offset;
/* Random number generator. */
const uint rng_hash = hash_uint(seed) ^ kernel_data.integrator.seed;
float filter_x, filter_y;
if (sample == 0) {
filter_x = filter_y = 0.5f;
}
else {
path_rng_2D(kg, rng_hash, sample, PRNG_FILTER_U, &filter_x, &filter_y);
}
/* Initialize path state for path integration. */
path_state_init_integrator(kg, state, sample, rng_hash);
/* Barycentric UV. */
float u = primitive[2];
float v = primitive[3];
float dudx = differential[0];
float dudy = differential[1];
float dvdx = differential[2];
float dvdy = differential[3];
/* Exactly at vertex? Nudge inwards to avoid self-intersection. */
if ((u == 0.0f || u == 1.0f) && (v == 0.0f || v == 1.0f)) {
const float2 uv = bake_offset_towards_center(kg, prim, u, v);
u = uv.x;
v = uv.y;
}
/* Sub-pixel offset. */
if (sample > 0) {
u = bake_clamp_mirror_repeat(u + dudx * (filter_x - 0.5f) + dudy * (filter_y - 0.5f), 1.0f);
v = bake_clamp_mirror_repeat(v + dvdx * (filter_x - 0.5f) + dvdy * (filter_y - 0.5f),
1.0f - u);
}
/* Position and normal on triangle. */
const int object = kernel_data.bake.object_index;
float3 P, Ng;
int shader;
triangle_point_normal(kg, object, prim, u, v, &P, &Ng, &shader);
const int object_flag = kernel_tex_fetch(__object_flag, object);
if (!(object_flag & SD_OBJECT_TRANSFORM_APPLIED)) {
Transform tfm = object_fetch_transform(kg, object, OBJECT_TRANSFORM);
P = transform_point_auto(&tfm, P);
}
if (kernel_data.film.pass_background != PASS_UNUSED) {
/* Environment baking. */
/* Setup and write ray. */
Ray ray ccl_optional_struct_init;
ray.P = zero_float3();
ray.D = normalize(P);
ray.t = FLT_MAX;
ray.time = 0.5f;
ray.dP = differential_zero_compact();
ray.dD = differential_zero_compact();
integrator_state_write_ray(kg, state, &ray);
/* Setup next kernel to execute. */
INTEGRATOR_PATH_INIT(DEVICE_KERNEL_INTEGRATOR_SHADE_BACKGROUND);
}
else {
/* Surface baking. */
float3 N = (shader & SHADER_SMOOTH_NORMAL) ? triangle_smooth_normal(kg, Ng, prim, u, v) : Ng;
if (!(object_flag & SD_OBJECT_TRANSFORM_APPLIED)) {
Transform itfm = object_fetch_transform(kg, object, OBJECT_INVERSE_TRANSFORM);
N = normalize(transform_direction_transposed(&itfm, N));
Ng = normalize(transform_direction_transposed(&itfm, Ng));
}
const int shader_index = shader & SHADER_MASK;
const int shader_flags = kernel_tex_fetch(__shaders, shader_index).flags;
/* Fast path for position and normal passes not affected by shaders. */
if (kernel_data.film.pass_position != PASS_UNUSED) {
kernel_write_pass_float3(buffer + kernel_data.film.pass_position, P);
return true;
}
else if (kernel_data.film.pass_normal != PASS_UNUSED && !(shader_flags & SD_HAS_BUMP)) {
kernel_write_pass_float3(buffer + kernel_data.film.pass_normal, N);
return true;
}
/* Setup ray. */
Ray ray ccl_optional_struct_init;
ray.P = P + N;
ray.D = -N;
ray.t = FLT_MAX;
ray.time = 0.5f;
/* Setup differentials. */
float3 dPdu, dPdv;
triangle_dPdudv(kg, prim, &dPdu, &dPdv);
if (!(object_flag & SD_OBJECT_TRANSFORM_APPLIED)) {
Transform tfm = object_fetch_transform(kg, object, OBJECT_TRANSFORM);
dPdu = transform_direction(&tfm, dPdu);
dPdv = transform_direction(&tfm, dPdv);
}
differential3 dP;
dP.dx = dPdu * dudx + dPdv * dvdx;
dP.dy = dPdu * dudy + dPdv * dvdy;
ray.dP = differential_make_compact(dP);
ray.dD = differential_zero_compact();
/* Write ray. */
integrator_state_write_ray(kg, state, &ray);
/* Setup and write intersection. */
Intersection isect ccl_optional_struct_init;
isect.object = kernel_data.bake.object_index;
isect.prim = prim;
isect.u = u;
isect.v = v;
isect.t = 1.0f;
isect.type = PRIMITIVE_TRIANGLE;
integrator_state_write_isect(kg, state, &isect);
/* Setup next kernel to execute. */
const bool use_caustics = kernel_data.integrator.use_caustics &&
(object_flag & SD_OBJECT_CAUSTICS);
const bool use_raytrace_kernel = (shader_flags & SD_HAS_RAYTRACE) || use_caustics;
if (use_raytrace_kernel) {
INTEGRATOR_PATH_INIT_SORTED(DEVICE_KERNEL_INTEGRATOR_SHADE_SURFACE_RAYTRACE, shader_index);
}
else {
INTEGRATOR_PATH_INIT_SORTED(DEVICE_KERNEL_INTEGRATOR_SHADE_SURFACE, shader_index);
}
}
return true;
}
CCL_NAMESPACE_END
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