Files
test/source/blender/blenkernel/intern/bake_items_socket.cc
Jacques Lucke 2d2b087fcf Geometry Nodes: support baking data block references
With this patch, materials are kept intact in simulation zones and bake nodes
without any additional user action.

This implements the design proposed in #108410 to support referencing
data-blocks (only materials for now) in the baked data. The task also describes
why this is not a trivial issue. A previous attempt was implemented in #109703
but it didn't work well-enough.

The solution is to have an explicit `name (+ library name) -> data-block`
mapping that is stored in the modifier for each bake node and simulation zone.
The `library name` is necessary for it to be unique within a .blend file. Note
that this refers to the name of the `Library` data-block and not a file path.
The baked data only contains the names of the used data-blocks. When the baked
data is loaded, the correct material data-block is looked up from the mapping.

### Automatic Mapping Generation

The most tricky aspect of this approach is to make it feel mostly automatic.
From the user point-of-view, it should just work. Therefore, we don't want the
user to have to create the mapping manually in the majority of cases. Creating
the mapping automatically is difficult because the data-blocks that should
become part of the mapping are only known during depsgraph evaluation. So we
somehow have to gather the missing data blocks during evaluation and then write
the new mappings back to the original data.

While writing back to original data is something we do in some cases already,
the situation here is different, because we are actually creating new relations
between data-blocks. This also means that we'll have to do user-counting. Since
user counts in data-blocks are *not* atomic, we can't do that from multiple
threads at the same time. Also, under some circumstances, it may be necessary to
trigger depsgraph evaluation again after the write-back because it actually
affects the result.

To solve this, a small new API is added in `DEG_depsgraph_writeback_sync.hh`. It
allows gathering tasks which write back to original data in a synchronous way
which may also require a reevaluation.

### Accessing the Mapping

A new `BakeDataBlockMap` is passed to geometry nodes evaluation by the modifier.
This map allows getting the `ID` pointer that should be used for a specific
data-block name that is stored in baked data. It's also used to gather all the
missing data mappings during evaluation.

### Weak ID References

The baked/cached geometries may have references to other data-blocks (currently
only materials, but in the future also e.g. instanced objects/collections).
However, the pointers of these data-blocks are not stable over time. That is
especially true when storing/loading the data from disk, but also just when
playing back the animation. Therefore, the used data-blocks have to referenced
in a different way at run-time.

This is solved by adding `std::unique_ptr<bake::BakeMaterialsList>` to the
run-time data of various geometry data-blocks. If the data-block is cached over
a longer period of time (such that material pointers can't be used directly), it
stores the material name (+ library name) used by each material slot. When the
geometry is used again, the material pointers are restored using these weak name
references and the `BakeDataBlockMap`.

### Manual Mapping Management

There is a new `Data-Blocks` panel in the bake settings in the node editor
sidebar that allows inspecting and modifying the data-blocks that are used when
baking. The user can change what data-block a specific name is mapped to.

Pull Request: https://projects.blender.org/blender/blender/pulls/117043
2024-02-01 09:21:55 +01:00

290 lines
11 KiB
C++

/* SPDX-FileCopyrightText: 2023 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
#include "BKE_bake_items_socket.hh"
#include "BKE_geometry_fields.hh"
#include "BKE_node.hh"
#include "BKE_node_socket_value.hh"
namespace blender::bke::bake {
Array<std::unique_ptr<BakeItem>> move_socket_values_to_bake_items(const Span<void *> socket_values,
const BakeSocketConfig &config,
BakeDataBlockMap *data_block_map)
{
BLI_assert(socket_values.size() == config.types.size());
BLI_assert(socket_values.size() == config.geometries_by_attribute.size());
Array<std::unique_ptr<BakeItem>> bake_items(socket_values.size());
/* Create geometry bake items first because they are used for field evaluation. */
for (const int i : socket_values.index_range()) {
const eNodeSocketDatatype socket_type = config.types[i];
if (socket_type != SOCK_GEOMETRY) {
continue;
}
void *socket_value = socket_values[i];
GeometrySet &geometry = *static_cast<GeometrySet *>(socket_value);
bake_items[i] = std::make_unique<GeometryBakeItem>(std::move(geometry));
}
for (const int i : socket_values.index_range()) {
const eNodeSocketDatatype socket_type = config.types[i];
void *socket_value = socket_values[i];
switch (socket_type) {
case SOCK_GEOMETRY: {
/* Handled already. */
break;
}
case SOCK_STRING: {
auto &value_variant = *static_cast<SocketValueVariant *>(socket_value);
bake_items[i] = std::make_unique<StringBakeItem>(value_variant.extract<std::string>());
break;
}
case SOCK_FLOAT:
case SOCK_VECTOR:
case SOCK_INT:
case SOCK_BOOLEAN:
case SOCK_ROTATION:
case SOCK_RGBA: {
auto &value_variant = *static_cast<SocketValueVariant *>(socket_value);
if (value_variant.is_context_dependent_field()) {
const fn::GField &field = value_variant.get<fn::GField>();
const AttrDomain domain = config.domains[i];
const std::string attribute_name = ".bake_" + std::to_string(i);
const Span<int> geometry_indices = config.geometries_by_attribute[i];
for (const int geometry_i : geometry_indices) {
BLI_assert(config.types[geometry_i] == SOCK_GEOMETRY);
GeometrySet &geometry =
static_cast<GeometryBakeItem *>(bake_items[geometry_i].get())->geometry;
if (geometry.has_pointcloud()) {
PointCloudComponent &component =
geometry.get_component_for_write<PointCloudComponent>();
try_capture_field_on_geometry(component, attribute_name, domain, field);
}
if (geometry.has_mesh()) {
MeshComponent &component = geometry.get_component_for_write<MeshComponent>();
try_capture_field_on_geometry(component, attribute_name, domain, field);
}
if (geometry.has_curves()) {
CurveComponent &component = geometry.get_component_for_write<CurveComponent>();
try_capture_field_on_geometry(component, attribute_name, domain, field);
}
if (geometry.has_instances()) {
InstancesComponent &component =
geometry.get_component_for_write<InstancesComponent>();
try_capture_field_on_geometry(component, attribute_name, domain, field);
}
}
bake_items[i] = std::make_unique<AttributeBakeItem>(attribute_name);
}
else {
value_variant.convert_to_single();
GPointer value = value_variant.get_single_ptr();
bake_items[i] = std::make_unique<PrimitiveBakeItem>(*value.type(), value.get());
}
break;
}
default:
break;
}
}
/* Cleanup geometries after fields have been evaluated. */
for (const int i : config.types.index_range()) {
const eNodeSocketDatatype socket_type = config.types[i];
if (socket_type != SOCK_GEOMETRY) {
continue;
}
GeometrySet &geometry = static_cast<GeometryBakeItem *>(bake_items[i].get())->geometry;
GeometryBakeItem::prepare_geometry_for_bake(geometry, data_block_map);
}
return bake_items;
}
[[nodiscard]] static bool copy_bake_item_to_socket_value(
const BakeItem &bake_item,
const eNodeSocketDatatype socket_type,
const FunctionRef<std::shared_ptr<AnonymousAttributeFieldInput>(const CPPType &type)>
make_attribute_field,
Map<std::string, AnonymousAttributeIDPtr> &r_attribute_map,
void *r_value)
{
switch (socket_type) {
case SOCK_GEOMETRY: {
if (const auto *item = dynamic_cast<const GeometryBakeItem *>(&bake_item)) {
new (r_value) GeometrySet(item->geometry);
return true;
}
return false;
}
case SOCK_FLOAT:
case SOCK_VECTOR:
case SOCK_INT:
case SOCK_BOOLEAN:
case SOCK_ROTATION:
case SOCK_RGBA: {
const CPPType &base_type = *socket_type_to_geo_nodes_base_cpp_type(socket_type);
if (const auto *item = dynamic_cast<const PrimitiveBakeItem *>(&bake_item)) {
if (item->type() == base_type) {
auto *value_variant = new (r_value) SocketValueVariant();
value_variant->store_single(socket_type, item->value());
return true;
}
return false;
}
if (const auto *item = dynamic_cast<const AttributeBakeItem *>(&bake_item)) {
std::shared_ptr<AnonymousAttributeFieldInput> attribute_field = make_attribute_field(
base_type);
const AnonymousAttributeIDPtr &attribute_id = attribute_field->anonymous_id();
fn::GField field{attribute_field};
new (r_value) SocketValueVariant(std::move(field));
r_attribute_map.add(item->name(), attribute_id);
return true;
}
return false;
}
case SOCK_STRING: {
if (const auto *item = dynamic_cast<const StringBakeItem *>(&bake_item)) {
new (r_value) SocketValueVariant(std::string(item->value()));
return true;
}
return false;
}
default:
return false;
}
return false;
}
static void rename_attributes(const Span<GeometrySet *> geometries,
const Map<std::string, AnonymousAttributeIDPtr> &attribute_map)
{
for (GeometrySet *geometry : geometries) {
for (const GeometryComponent::Type type : {GeometryComponent::Type::Mesh,
GeometryComponent::Type::Curve,
GeometryComponent::Type::PointCloud,
GeometryComponent::Type::Instance})
{
if (!geometry->has(type)) {
continue;
}
/* Avoid write access on the geometry when unnecessary to avoid copying data-blocks. */
const AttributeAccessor attributes_read_only = *geometry->get_component(type)->attributes();
if (std::none_of(attribute_map.keys().begin(),
attribute_map.keys().end(),
[&](const StringRef name) { return attributes_read_only.contains(name); }))
{
continue;
}
GeometryComponent &component = geometry->get_component_for_write(type);
MutableAttributeAccessor attributes = *component.attributes_for_write();
for (const MapItem<std::string, AnonymousAttributeIDPtr> &attribute_item :
attribute_map.items())
{
attributes.rename(attribute_item.key, *attribute_item.value);
}
}
}
}
static void restore_data_blocks(const Span<GeometrySet *> geometries,
BakeDataBlockMap *data_block_map)
{
for (GeometrySet *main_geometry : geometries) {
GeometryBakeItem::try_restore_data_blocks(*main_geometry, data_block_map);
}
}
static void default_initialize_socket_value(const eNodeSocketDatatype socket_type, void *r_value)
{
const char *socket_idname = nodeStaticSocketType(socket_type, 0);
const bNodeSocketType *typeinfo = nodeSocketTypeFind(socket_idname);
typeinfo->geometry_nodes_cpp_type->copy_construct(typeinfo->geometry_nodes_default_cpp_value,
r_value);
}
void move_bake_items_to_socket_values(
const Span<BakeItem *> bake_items,
const BakeSocketConfig &config,
BakeDataBlockMap *data_block_map,
FunctionRef<std::shared_ptr<AnonymousAttributeFieldInput>(int, const CPPType &)>
make_attribute_field,
const Span<void *> r_socket_values)
{
Map<std::string, AnonymousAttributeIDPtr> attribute_map;
Vector<GeometrySet *> geometries;
for (const int i : bake_items.index_range()) {
const eNodeSocketDatatype socket_type = config.types[i];
BakeItem *bake_item = bake_items[i];
void *r_socket_value = r_socket_values[i];
if (bake_item == nullptr) {
default_initialize_socket_value(socket_type, r_socket_value);
continue;
}
if (!copy_bake_item_to_socket_value(
*bake_item,
socket_type,
[&](const CPPType &attr_type) { return make_attribute_field(i, attr_type); },
attribute_map,
r_socket_value))
{
default_initialize_socket_value(socket_type, r_socket_value);
continue;
}
if (socket_type == SOCK_GEOMETRY) {
auto &item = *static_cast<GeometryBakeItem *>(bake_item);
item.geometry.clear();
geometries.append(static_cast<GeometrySet *>(r_socket_value));
}
}
rename_attributes(geometries, attribute_map);
restore_data_blocks(geometries, data_block_map);
}
void copy_bake_items_to_socket_values(
const Span<const BakeItem *> bake_items,
const BakeSocketConfig &config,
BakeDataBlockMap *data_block_map,
FunctionRef<std::shared_ptr<AnonymousAttributeFieldInput>(int, const CPPType &)>
make_attribute_field,
const Span<void *> r_socket_values)
{
Map<std::string, AnonymousAttributeIDPtr> attribute_map;
Vector<GeometrySet *> geometries;
for (const int i : bake_items.index_range()) {
const eNodeSocketDatatype socket_type = config.types[i];
const BakeItem *bake_item = bake_items[i];
void *r_socket_value = r_socket_values[i];
if (bake_item == nullptr) {
default_initialize_socket_value(socket_type, r_socket_value);
continue;
}
if (!copy_bake_item_to_socket_value(
*bake_item,
socket_type,
[&](const CPPType &attr_type) { return make_attribute_field(i, attr_type); },
attribute_map,
r_socket_value))
{
default_initialize_socket_value(socket_type, r_socket_value);
continue;
}
if (socket_type == SOCK_GEOMETRY) {
geometries.append(static_cast<GeometrySet *>(r_socket_value));
}
}
rename_attributes(geometries, attribute_map);
restore_data_blocks(geometries, data_block_map);
}
} // namespace blender::bke::bake