Files
test/source/blender/blenkernel/intern/viewer_path.cc
Jacques Lucke 6e5e01e630 Geometry Nodes: new For Each Geometry Element zone
This adds a new type of zone to Geometry Nodes that allows executing some nodes
for each element in a geometry.

## Features

* The `Selection` input allows iterating over a subset of elements on the set
  domain.
* Fields passed into the input node are available as single values inside of the
  zone.
* The input geometry can be split up into separate (completely independent)
  geometries for each element (on all domains except face corner).
* New attributes can be created on the input geometry by outputting a single
  value from each iteration.
* New geometries can be generated in each iteration.
    * All of these geometries are joined to form the final output.
    * Attributes from the input geometry are propagated to the output
      geometries.

## Evaluation

The evaluation strategy is similar to the one used for repeat zones. Namely, it
dynamically builds a `lazy_function::Graph` once it knows how many iterations
are necessary. It contains a separate node for each iteration. The inputs for
each iteration are hardcoded into the graph. The outputs of each iteration a
passed to a separate lazy-function that reduces all the values down to the final
outputs. This final output can have a huge number of inputs and that is not
ideal for multi-threading yet, but that can still be improved in the future.

## Performance

There is a non-neglilible amount of overhead for each iteration. The overhead is
way larger than the per-element overhead when just doing field evaluation.
Therefore, normal field evaluation should be preferred when possible. That can
partially still be optimized if there is only some number crunching going on in
the zone but that optimization is not implemented yet.

However, processing many small geometries (e.g. each hair of a character
separately) will likely **always be slower** than working on fewer larger
geoemtries. The additional flexibility you get by processing each element
separately comes at the cost that Blender can't optimize the operation as well.
For node groups that need to handle lots of geometry elements, we recommend
trying to design the node setup so that iteration over tiny sub-geometries is
not required.

An opposite point is true as well though. It can be faster to process more
medium sized geometries in parallel than fewer very large geometries because of
more multi-threading opportunities. The exact threshold between tiny, medium and
large geometries depends on a lot of factors though.

Overall, this initial version of the new zone does not implement all
optimization opportunities yet, but the points mentioned above will still hold
true later.

Pull Request: https://projects.blender.org/blender/blender/pulls/127331
2024-09-24 11:52:02 +02:00

383 lines
14 KiB
C++

/* SPDX-FileCopyrightText: 2023 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#include "BKE_lib_query.hh"
#include "BKE_lib_remap.hh"
#include "BKE_viewer_path.hh"
#include "BLI_index_range.hh"
#include "BLI_listbase.h"
#include "BLI_string.h"
#include "BLI_string_ref.hh"
#include "MEM_guardedalloc.h"
#include "BLO_read_write.hh"
using blender::IndexRange;
using blender::StringRef;
void BKE_viewer_path_init(ViewerPath *viewer_path)
{
BLI_listbase_clear(&viewer_path->path);
}
void BKE_viewer_path_clear(ViewerPath *viewer_path)
{
LISTBASE_FOREACH_MUTABLE (ViewerPathElem *, elem, &viewer_path->path) {
BKE_viewer_path_elem_free(elem);
}
BLI_listbase_clear(&viewer_path->path);
}
void BKE_viewer_path_copy(ViewerPath *dst, const ViewerPath *src)
{
BKE_viewer_path_init(dst);
LISTBASE_FOREACH (const ViewerPathElem *, src_elem, &src->path) {
ViewerPathElem *new_elem = BKE_viewer_path_elem_copy(src_elem);
BLI_addtail(&dst->path, new_elem);
}
}
bool BKE_viewer_path_equal(const ViewerPath *a,
const ViewerPath *b,
const ViewerPathEqualFlag flag)
{
const ViewerPathElem *elem_a = static_cast<const ViewerPathElem *>(a->path.first);
const ViewerPathElem *elem_b = static_cast<const ViewerPathElem *>(b->path.first);
while (elem_a != nullptr && elem_b != nullptr) {
if (!BKE_viewer_path_elem_equal(elem_a, elem_b, flag)) {
return false;
}
elem_a = elem_a->next;
elem_b = elem_b->next;
}
if (elem_a == nullptr && elem_b == nullptr) {
return true;
}
return false;
}
void BKE_viewer_path_blend_write(BlendWriter *writer, const ViewerPath *viewer_path)
{
LISTBASE_FOREACH (ViewerPathElem *, elem, &viewer_path->path) {
switch (ViewerPathElemType(elem->type)) {
case VIEWER_PATH_ELEM_TYPE_ID: {
const auto *typed_elem = reinterpret_cast<IDViewerPathElem *>(elem);
BLO_write_struct(writer, IDViewerPathElem, typed_elem);
break;
}
case VIEWER_PATH_ELEM_TYPE_MODIFIER: {
const auto *typed_elem = reinterpret_cast<ModifierViewerPathElem *>(elem);
BLO_write_struct(writer, ModifierViewerPathElem, typed_elem);
BLO_write_string(writer, typed_elem->modifier_name);
break;
}
case VIEWER_PATH_ELEM_TYPE_GROUP_NODE: {
const auto *typed_elem = reinterpret_cast<GroupNodeViewerPathElem *>(elem);
BLO_write_struct(writer, GroupNodeViewerPathElem, typed_elem);
break;
}
case VIEWER_PATH_ELEM_TYPE_SIMULATION_ZONE: {
const auto *typed_elem = reinterpret_cast<SimulationZoneViewerPathElem *>(elem);
BLO_write_struct(writer, SimulationZoneViewerPathElem, typed_elem);
break;
}
case VIEWER_PATH_ELEM_TYPE_VIEWER_NODE: {
const auto *typed_elem = reinterpret_cast<ViewerNodeViewerPathElem *>(elem);
BLO_write_struct(writer, ViewerNodeViewerPathElem, typed_elem);
break;
}
case VIEWER_PATH_ELEM_TYPE_REPEAT_ZONE: {
const auto *typed_elem = reinterpret_cast<RepeatZoneViewerPathElem *>(elem);
BLO_write_struct(writer, RepeatZoneViewerPathElem, typed_elem);
break;
}
case VIEWER_PATH_ELEM_TYPE_FOREACH_GEOMETRY_ELEMENT_ZONE: {
const auto *typed_elem = reinterpret_cast<ForeachGeometryElementZoneViewerPathElem *>(
elem);
BLO_write_struct(writer, ForeachGeometryElementZoneViewerPathElem, typed_elem);
break;
}
}
BLO_write_string(writer, elem->ui_name);
}
}
void BKE_viewer_path_blend_read_data(BlendDataReader *reader, ViewerPath *viewer_path)
{
BLO_read_struct_list(reader, ViewerPathElem, &viewer_path->path);
LISTBASE_FOREACH (ViewerPathElem *, elem, &viewer_path->path) {
BLO_read_string(reader, &elem->ui_name);
switch (ViewerPathElemType(elem->type)) {
case VIEWER_PATH_ELEM_TYPE_GROUP_NODE:
case VIEWER_PATH_ELEM_TYPE_SIMULATION_ZONE:
case VIEWER_PATH_ELEM_TYPE_VIEWER_NODE:
case VIEWER_PATH_ELEM_TYPE_REPEAT_ZONE:
case VIEWER_PATH_ELEM_TYPE_FOREACH_GEOMETRY_ELEMENT_ZONE:
case VIEWER_PATH_ELEM_TYPE_ID: {
break;
}
case VIEWER_PATH_ELEM_TYPE_MODIFIER: {
auto *typed_elem = reinterpret_cast<ModifierViewerPathElem *>(elem);
BLO_read_string(reader, &typed_elem->modifier_name);
break;
}
}
}
}
void BKE_viewer_path_foreach_id(LibraryForeachIDData *data, ViewerPath *viewer_path)
{
LISTBASE_FOREACH (ViewerPathElem *, elem, &viewer_path->path) {
switch (ViewerPathElemType(elem->type)) {
case VIEWER_PATH_ELEM_TYPE_ID: {
auto *typed_elem = reinterpret_cast<IDViewerPathElem *>(elem);
BKE_LIB_FOREACHID_PROCESS_ID(data, typed_elem->id, IDWALK_CB_DIRECT_WEAK_LINK);
break;
}
case VIEWER_PATH_ELEM_TYPE_MODIFIER:
case VIEWER_PATH_ELEM_TYPE_GROUP_NODE:
case VIEWER_PATH_ELEM_TYPE_SIMULATION_ZONE:
case VIEWER_PATH_ELEM_TYPE_VIEWER_NODE:
case VIEWER_PATH_ELEM_TYPE_REPEAT_ZONE:
case VIEWER_PATH_ELEM_TYPE_FOREACH_GEOMETRY_ELEMENT_ZONE: {
break;
}
}
}
}
void BKE_viewer_path_id_remap(ViewerPath *viewer_path,
const blender::bke::id::IDRemapper &mappings)
{
LISTBASE_FOREACH (ViewerPathElem *, elem, &viewer_path->path) {
switch (ViewerPathElemType(elem->type)) {
case VIEWER_PATH_ELEM_TYPE_ID: {
auto *typed_elem = reinterpret_cast<IDViewerPathElem *>(elem);
mappings.apply(&typed_elem->id, ID_REMAP_APPLY_DEFAULT);
break;
}
case VIEWER_PATH_ELEM_TYPE_MODIFIER:
case VIEWER_PATH_ELEM_TYPE_GROUP_NODE:
case VIEWER_PATH_ELEM_TYPE_SIMULATION_ZONE:
case VIEWER_PATH_ELEM_TYPE_VIEWER_NODE:
case VIEWER_PATH_ELEM_TYPE_REPEAT_ZONE:
case VIEWER_PATH_ELEM_TYPE_FOREACH_GEOMETRY_ELEMENT_ZONE: {
break;
}
}
}
}
template<typename T> static T *make_elem(const ViewerPathElemType type)
{
T *elem = MEM_cnew<T>(__func__);
elem->base.type = type;
return elem;
}
ViewerPathElem *BKE_viewer_path_elem_new(const ViewerPathElemType type)
{
switch (type) {
case VIEWER_PATH_ELEM_TYPE_ID: {
return &make_elem<IDViewerPathElem>(type)->base;
}
case VIEWER_PATH_ELEM_TYPE_MODIFIER: {
return &make_elem<ModifierViewerPathElem>(type)->base;
}
case VIEWER_PATH_ELEM_TYPE_GROUP_NODE: {
return &make_elem<GroupNodeViewerPathElem>(type)->base;
}
case VIEWER_PATH_ELEM_TYPE_SIMULATION_ZONE: {
return &make_elem<SimulationZoneViewerPathElem>(type)->base;
}
case VIEWER_PATH_ELEM_TYPE_VIEWER_NODE: {
return &make_elem<ViewerNodeViewerPathElem>(type)->base;
}
case VIEWER_PATH_ELEM_TYPE_REPEAT_ZONE: {
return &make_elem<RepeatZoneViewerPathElem>(type)->base;
}
case VIEWER_PATH_ELEM_TYPE_FOREACH_GEOMETRY_ELEMENT_ZONE: {
return &make_elem<ForeachGeometryElementZoneViewerPathElem>(type)->base;
}
}
BLI_assert_unreachable();
return nullptr;
}
IDViewerPathElem *BKE_viewer_path_elem_new_id()
{
return reinterpret_cast<IDViewerPathElem *>(BKE_viewer_path_elem_new(VIEWER_PATH_ELEM_TYPE_ID));
}
ModifierViewerPathElem *BKE_viewer_path_elem_new_modifier()
{
return reinterpret_cast<ModifierViewerPathElem *>(
BKE_viewer_path_elem_new(VIEWER_PATH_ELEM_TYPE_MODIFIER));
}
GroupNodeViewerPathElem *BKE_viewer_path_elem_new_group_node()
{
return reinterpret_cast<GroupNodeViewerPathElem *>(
BKE_viewer_path_elem_new(VIEWER_PATH_ELEM_TYPE_GROUP_NODE));
}
SimulationZoneViewerPathElem *BKE_viewer_path_elem_new_simulation_zone()
{
return reinterpret_cast<SimulationZoneViewerPathElem *>(
BKE_viewer_path_elem_new(VIEWER_PATH_ELEM_TYPE_SIMULATION_ZONE));
}
ViewerNodeViewerPathElem *BKE_viewer_path_elem_new_viewer_node()
{
return reinterpret_cast<ViewerNodeViewerPathElem *>(
BKE_viewer_path_elem_new(VIEWER_PATH_ELEM_TYPE_VIEWER_NODE));
}
RepeatZoneViewerPathElem *BKE_viewer_path_elem_new_repeat_zone()
{
return reinterpret_cast<RepeatZoneViewerPathElem *>(
BKE_viewer_path_elem_new(VIEWER_PATH_ELEM_TYPE_REPEAT_ZONE));
}
ForeachGeometryElementZoneViewerPathElem *BKE_viewer_path_elem_new_foreach_geometry_element_zone()
{
return reinterpret_cast<ForeachGeometryElementZoneViewerPathElem *>(
BKE_viewer_path_elem_new(VIEWER_PATH_ELEM_TYPE_FOREACH_GEOMETRY_ELEMENT_ZONE));
}
ViewerPathElem *BKE_viewer_path_elem_copy(const ViewerPathElem *src)
{
ViewerPathElem *dst = BKE_viewer_path_elem_new(ViewerPathElemType(src->type));
if (src->ui_name) {
dst->ui_name = BLI_strdup(src->ui_name);
}
switch (ViewerPathElemType(src->type)) {
case VIEWER_PATH_ELEM_TYPE_ID: {
const auto *old_elem = reinterpret_cast<const IDViewerPathElem *>(src);
auto *new_elem = reinterpret_cast<IDViewerPathElem *>(dst);
new_elem->id = old_elem->id;
break;
}
case VIEWER_PATH_ELEM_TYPE_MODIFIER: {
const auto *old_elem = reinterpret_cast<const ModifierViewerPathElem *>(src);
auto *new_elem = reinterpret_cast<ModifierViewerPathElem *>(dst);
if (old_elem->modifier_name != nullptr) {
new_elem->modifier_name = BLI_strdup(old_elem->modifier_name);
}
break;
}
case VIEWER_PATH_ELEM_TYPE_GROUP_NODE: {
const auto *old_elem = reinterpret_cast<const GroupNodeViewerPathElem *>(src);
auto *new_elem = reinterpret_cast<GroupNodeViewerPathElem *>(dst);
new_elem->node_id = old_elem->node_id;
break;
}
case VIEWER_PATH_ELEM_TYPE_SIMULATION_ZONE: {
const auto *old_elem = reinterpret_cast<const SimulationZoneViewerPathElem *>(src);
auto *new_elem = reinterpret_cast<SimulationZoneViewerPathElem *>(dst);
new_elem->sim_output_node_id = old_elem->sim_output_node_id;
break;
}
case VIEWER_PATH_ELEM_TYPE_VIEWER_NODE: {
const auto *old_elem = reinterpret_cast<const ViewerNodeViewerPathElem *>(src);
auto *new_elem = reinterpret_cast<ViewerNodeViewerPathElem *>(dst);
new_elem->node_id = old_elem->node_id;
break;
}
case VIEWER_PATH_ELEM_TYPE_REPEAT_ZONE: {
const auto *old_elem = reinterpret_cast<const RepeatZoneViewerPathElem *>(src);
auto *new_elem = reinterpret_cast<RepeatZoneViewerPathElem *>(dst);
new_elem->repeat_output_node_id = old_elem->repeat_output_node_id;
new_elem->iteration = old_elem->iteration;
break;
}
case VIEWER_PATH_ELEM_TYPE_FOREACH_GEOMETRY_ELEMENT_ZONE: {
const auto *old_elem = reinterpret_cast<const ForeachGeometryElementZoneViewerPathElem *>(
src);
auto *new_elem = reinterpret_cast<ForeachGeometryElementZoneViewerPathElem *>(dst);
new_elem->zone_output_node_id = old_elem->zone_output_node_id;
new_elem->index = old_elem->index;
break;
}
}
return dst;
}
bool BKE_viewer_path_elem_equal(const ViewerPathElem *a,
const ViewerPathElem *b,
const ViewerPathEqualFlag flag)
{
if (a->type != b->type) {
return false;
}
switch (ViewerPathElemType(a->type)) {
case VIEWER_PATH_ELEM_TYPE_ID: {
const auto *a_elem = reinterpret_cast<const IDViewerPathElem *>(a);
const auto *b_elem = reinterpret_cast<const IDViewerPathElem *>(b);
return a_elem->id == b_elem->id;
}
case VIEWER_PATH_ELEM_TYPE_MODIFIER: {
const auto *a_elem = reinterpret_cast<const ModifierViewerPathElem *>(a);
const auto *b_elem = reinterpret_cast<const ModifierViewerPathElem *>(b);
return StringRef(a_elem->modifier_name) == StringRef(b_elem->modifier_name);
}
case VIEWER_PATH_ELEM_TYPE_GROUP_NODE: {
const auto *a_elem = reinterpret_cast<const GroupNodeViewerPathElem *>(a);
const auto *b_elem = reinterpret_cast<const GroupNodeViewerPathElem *>(b);
return a_elem->node_id == b_elem->node_id;
}
case VIEWER_PATH_ELEM_TYPE_SIMULATION_ZONE: {
const auto *a_elem = reinterpret_cast<const SimulationZoneViewerPathElem *>(a);
const auto *b_elem = reinterpret_cast<const SimulationZoneViewerPathElem *>(b);
return a_elem->sim_output_node_id == b_elem->sim_output_node_id;
}
case VIEWER_PATH_ELEM_TYPE_VIEWER_NODE: {
const auto *a_elem = reinterpret_cast<const ViewerNodeViewerPathElem *>(a);
const auto *b_elem = reinterpret_cast<const ViewerNodeViewerPathElem *>(b);
return a_elem->node_id == b_elem->node_id;
}
case VIEWER_PATH_ELEM_TYPE_REPEAT_ZONE: {
const auto *a_elem = reinterpret_cast<const RepeatZoneViewerPathElem *>(a);
const auto *b_elem = reinterpret_cast<const RepeatZoneViewerPathElem *>(b);
return a_elem->repeat_output_node_id == b_elem->repeat_output_node_id &&
((flag & VIEWER_PATH_EQUAL_FLAG_IGNORE_ITERATION) != 0 ||
a_elem->iteration == b_elem->iteration);
}
case VIEWER_PATH_ELEM_TYPE_FOREACH_GEOMETRY_ELEMENT_ZONE: {
const auto *a_elem = reinterpret_cast<const ForeachGeometryElementZoneViewerPathElem *>(a);
const auto *b_elem = reinterpret_cast<const ForeachGeometryElementZoneViewerPathElem *>(b);
return a_elem->zone_output_node_id == b_elem->zone_output_node_id &&
((flag & VIEWER_PATH_EQUAL_FLAG_IGNORE_ITERATION) != 0 ||
a_elem->index == b_elem->index);
}
}
return false;
}
void BKE_viewer_path_elem_free(ViewerPathElem *elem)
{
switch (ViewerPathElemType(elem->type)) {
case VIEWER_PATH_ELEM_TYPE_ID:
case VIEWER_PATH_ELEM_TYPE_GROUP_NODE:
case VIEWER_PATH_ELEM_TYPE_SIMULATION_ZONE:
case VIEWER_PATH_ELEM_TYPE_VIEWER_NODE:
case VIEWER_PATH_ELEM_TYPE_REPEAT_ZONE:
case VIEWER_PATH_ELEM_TYPE_FOREACH_GEOMETRY_ELEMENT_ZONE: {
break;
}
case VIEWER_PATH_ELEM_TYPE_MODIFIER: {
auto *typed_elem = reinterpret_cast<ModifierViewerPathElem *>(elem);
MEM_SAFE_FREE(typed_elem->modifier_name);
break;
}
}
if (elem->ui_name) {
MEM_freeN(elem->ui_name);
}
MEM_freeN(elem);
}