Files
test/intern/cycles/kernel/util/texture_3d.h
2025-07-18 12:03:53 +10:00

343 lines
9.6 KiB
C++

/* SPDX-FileCopyrightText: 2011-2025 Blender Foundation
*
* SPDX-License-Identifier: Apache-2.0 */
#pragma once
#include "kernel/globals.h"
#include "util/texture.h"
#if !defined(__KERNEL_METAL__) && !defined(__KERNEL_ONEAPI__)
# ifdef WITH_NANOVDB
# include "kernel/util/nanovdb.h"
# endif
#endif
CCL_NAMESPACE_BEGIN
#ifndef __KERNEL_GPU__
/* Make template functions private so symbols don't conflict between kernels with different
* instruction sets. */
namespace {
#endif
#ifdef WITH_NANOVDB
/* Stochastically turn a tricubic filter into a trilinear filter. */
ccl_device_inline float3 interp_tricubic_to_trilinear_stochastic(const float3 P, float randu)
{
/* Some optimizations possible:
* - Could use select() for SIMD if we split the random number into 10
* bits each and use that for each dimensions.
* - For GPU would be better not to compute P0 and P1 for all dimensions
* in advance?
* - 1/g0 and 1/(1 - g0) are computed twice.
*/
const float3 p = floor(P);
const float3 t = P - p;
/* Cubic weights. */
const float3 w0 = (1.0f / 6.0f) * (t * (t * (-t + 3.0f) - 3.0f) + 1.0f);
const float3 w1 = (1.0f / 6.0f) * (t * t * (3.0f * t - 6.0f) + 4.0f);
// float3 w2 = (1.0f / 6.0f) * (t * (t * (-3.0f * t + 3.0f) + 3.0f) + 1.0f);
const float3 w3 = (1.0f / 6.0f) * (t * t * t);
const float3 g0 = w0 + w1;
const float3 P0 = p + (w1 / g0) - 1.0f;
const float3 P1 = p + (w3 / (make_float3(1.0f) - g0)) + 1.0f;
float3 Pnew = P0;
if (randu < g0.x) {
randu /= g0.x;
}
else {
Pnew.x = P1.x;
randu = (randu - g0.x) / (1 - g0.x);
}
if (randu < g0.y) {
randu /= g0.y;
}
else {
Pnew.y = P1.y;
randu = (randu - g0.y) / (1 - g0.y);
}
if (randu < g0.z) {
}
else {
Pnew.z = P1.z;
}
return Pnew;
}
/* From "Stochastic Texture Filtering": https://arxiv.org/abs/2305.05810
*
* Could be used in specific situations where we are certain a single
* tap is enough. Maybe better to try optimizing bilinear lookups in
* NanoVDB (detect when fully inside a single leaf) than deal with this. */
# if 0
ccl_device int3 interp_tricubic_stochastic(const float3 P, float randu)
{
const float ix = floorf(P.x);
const float iy = floorf(P.y);
const float iz = floorf(P.z);
const float deltas[3] = {P.x - ix, P.y - iy, P.z - iz};
int idx[3] = {(int)ix - 1, (int)iy - 1, (int)iz - 1};
for (int i = 0; i < 3; i++) {
const float t = deltas[i];
const float t2 = t * t;
/* Weighted reservoir sampling, first tap always accepted */
const float w0 = (1.0f / 6.0f) * (-t * t2 + 3 * t2 - 3 * t + 1);
float sumWt = w0;
int index = 0;
/* TODO: reduce number of divisions? */
/* Sample the other 3 filter taps. */
{
const float w1 = (1.0f / 6.0f) * (3 * t * t2 - 6 * t2 + 4);
sumWt += w1;
const float p = w1 / sumWt;
if (randu < p) {
index = 1;
randu /= p;
}
else {
randu = (randu - p) / (1 - p);
}
}
{
const float w2 = (1.0f / 6.0f) * (-3 * t * t2 + 3 * t2 + 3 * t + 1);
sumWt += w2;
const float p = w2 / sumWt;
if (randu < p) {
index = 2;
randu /= p;
}
else {
randu = (randu - p) / (1 - p);
}
}
{
const float w3 = (1.0f / 6.0f) * t * t2;
sumWt += w3;
const float p = w3 / sumWt;
if (randu < p) {
index = 3;
randu /= p;
}
else {
randu = (randu - p) / (1 - p);
}
}
idx[i] += index;
}
return make_int3(idx[0], idx[1], idx[2]);
}
ccl_device int3 interp_trilinear_stochastic(const float3 P, float randu)
{
const float ix = floorf(P.x);
const float iy = floorf(P.y);
const float iz = floorf(P.z);
int idx[3] = {(int)ix, (int)iy, (int)iz};
const float tx = P.x - ix;
const float ty = P.y - iy;
const float tz = P.z - iz;
if (randu < tx) {
idx[0]++;
randu /= tx;
}
else {
randu = (randu - tx) / (1 - tx);
}
if (randu < ty) {
idx[1]++;
randu /= ty;
}
else {
randu = (randu - ty) / (1 - ty);
}
if (randu < tz) {
idx[2]++;
}
return make_int3(idx[0], idx[1], idx[2]);
}
# endif
template<typename OutT, typename Acc>
ccl_device OutT kernel_tex_image_interp_trilinear_nanovdb(ccl_private Acc &acc, const float3 P)
{
const float3 floor_P = floor(P);
const float3 t = P - floor_P;
const int3 index = make_int3(floor_P);
const int ix = index.x;
const int iy = index.y;
const int iz = index.z;
return mix(mix(mix(OutT(acc.getValue(make_int3(ix, iy, iz))),
OutT(acc.getValue(make_int3(ix, iy, iz + 1))),
t.z),
mix(OutT(acc.getValue(make_int3(ix, iy + 1, iz + 1))),
OutT(acc.getValue(make_int3(ix, iy + 1, iz))),
1.0f - t.z),
t.y),
mix(mix(OutT(acc.getValue(make_int3(ix + 1, iy + 1, iz))),
OutT(acc.getValue(make_int3(ix + 1, iy + 1, iz + 1))),
t.z),
mix(OutT(acc.getValue(make_int3(ix + 1, iy, iz + 1))),
OutT(acc.getValue(make_int3(ix + 1, iy, iz))),
1.0f - t.z),
1.0f - t.y),
t.x);
}
template<typename OutT, typename Acc>
ccl_device OutT kernel_tex_image_interp_tricubic_nanovdb(ccl_private Acc &acc, const float3 P)
{
const float3 floor_P = floor(P);
const float3 t = P - floor_P;
const int3 index = make_int3(floor_P);
const int xc[4] = {index.x - 1, index.x, index.x + 1, index.x + 2};
const int yc[4] = {index.y - 1, index.y, index.y + 1, index.y + 2};
const int zc[4] = {index.z - 1, index.z, index.z + 1, index.z + 2};
float u[4], v[4], w[4];
/* Some helper macros to keep code size reasonable.
* Lets the compiler inline all the matrix multiplications.
*/
# define SET_CUBIC_SPLINE_WEIGHTS(u, t) \
{ \
u[0] = (((-1.0f / 6.0f) * t + 0.5f) * t - 0.5f) * t + (1.0f / 6.0f); \
u[1] = ((0.5f * t - 1.0f) * t) * t + (2.0f / 3.0f); \
u[2] = ((-0.5f * t + 0.5f) * t + 0.5f) * t + (1.0f / 6.0f); \
u[3] = (1.0f / 6.0f) * t * t * t; \
} \
(void)0
# define DATA(x, y, z) (OutT(acc.getValue(make_int3(xc[x], yc[y], zc[z]))))
# define COL_TERM(col, row) \
(v[col] * (u[0] * DATA(0, col, row) + u[1] * DATA(1, col, row) + u[2] * DATA(2, col, row) + \
u[3] * DATA(3, col, row)))
# define ROW_TERM(row) \
(w[row] * (COL_TERM(0, row) + COL_TERM(1, row) + COL_TERM(2, row) + COL_TERM(3, row)))
SET_CUBIC_SPLINE_WEIGHTS(u, t.x);
SET_CUBIC_SPLINE_WEIGHTS(v, t.y);
SET_CUBIC_SPLINE_WEIGHTS(w, t.z);
/* Actual interpolation. */
return ROW_TERM(0) + ROW_TERM(1) + ROW_TERM(2) + ROW_TERM(3);
# undef COL_TERM
# undef ROW_TERM
# undef DATA
# undef SET_CUBIC_SPLINE_WEIGHTS
}
template<typename OutT, typename T>
# if defined(__KERNEL_METAL__)
__attribute__((noinline))
# else
ccl_device_noinline
# endif
OutT kernel_tex_image_interp_nanovdb(const ccl_global TextureInfo &info,
float3 P,
const InterpolationType interp)
{
ccl_global nanovdb::NanoGrid<T> *const grid = (ccl_global nanovdb::NanoGrid<T> *)info.data;
if (interp == INTERPOLATION_CLOSEST) {
nanovdb::ReadAccessor<T> acc(grid->tree().root());
return OutT(acc.getValue(make_int3(floor(P))));
}
nanovdb::CachedReadAccessor<T> acc(grid->tree().root());
if (interp == INTERPOLATION_LINEAR) {
return kernel_tex_image_interp_trilinear_nanovdb<OutT>(acc, P);
}
return kernel_tex_image_interp_tricubic_nanovdb<OutT>(acc, P);
}
#endif /* WITH_NANOVDB */
ccl_device float4 kernel_tex_image_interp_3d(
KernelGlobals kg, const int id, float3 P, InterpolationType interp, const float randu)
{
#ifdef WITH_NANOVDB
const ccl_global TextureInfo &info = kernel_data_fetch(texture_info, id);
if (info.use_transform_3d) {
P = transform_point(&info.transform_3d, P);
}
InterpolationType interpolation = (interp == INTERPOLATION_NONE) ?
(InterpolationType)info.interpolation :
interp;
/* A -0.5 offset is used to center the cubic samples around the sample point. */
P = P - make_float3(0.5f);
if (interpolation == INTERPOLATION_CUBIC && randu >= 0.0f) {
P = interp_tricubic_to_trilinear_stochastic(P, randu);
interpolation = INTERPOLATION_LINEAR;
}
const ImageDataType data_type = (ImageDataType)info.data_type;
if (data_type == IMAGE_DATA_TYPE_NANOVDB_FLOAT) {
const float f = kernel_tex_image_interp_nanovdb<float, float>(info, P, interpolation);
return make_float4(f, f, f, 1.0f);
}
if (data_type == IMAGE_DATA_TYPE_NANOVDB_FLOAT3) {
const float3 f = kernel_tex_image_interp_nanovdb<float3, packed_float3>(
info, P, interpolation);
return make_float4(f, 1.0f);
}
if (data_type == IMAGE_DATA_TYPE_NANOVDB_FLOAT4) {
return kernel_tex_image_interp_nanovdb<float4, float4>(info, P, interpolation);
}
if (data_type == IMAGE_DATA_TYPE_NANOVDB_FPN) {
const float f = kernel_tex_image_interp_nanovdb<float, nanovdb::FpN>(info, P, interpolation);
return make_float4(f, f, f, 1.0f);
}
if (data_type == IMAGE_DATA_TYPE_NANOVDB_FP16) {
const float f = kernel_tex_image_interp_nanovdb<float, nanovdb::Fp16>(info, P, interpolation);
return make_float4(f, f, f, 1.0f);
}
if (data_type == IMAGE_DATA_TYPE_NANOVDB_EMPTY) {
return zero_float4();
}
#else
(void)kg;
(void)id;
(void)P;
(void)interp;
(void)randu;
#endif
return make_float4(
TEX_IMAGE_MISSING_R, TEX_IMAGE_MISSING_G, TEX_IMAGE_MISSING_B, TEX_IMAGE_MISSING_A);
}
#ifndef __KERNEL_GPU__
} /* Namespace. */
#endif
CCL_NAMESPACE_END