Commit Graph

13 Commits

Author SHA1 Message Date
ef76a67153 Cleanup: doxy comment formatting 2022-11-01 12:24:04 +11:00
f61ff22967 Attribute Node: support accessing attributes of View Layer and Scene.
The attribute node already allows accessing attributes associated
with objects and meshes, which allows changing the behavior of the
same material between different objects or instances. The same idea
can be extended to an even more global level of layers and scenes.

Currently view layers provide an option to replace all materials
with a different one. However, since the same material will be applied
to all objects in the layer, varying the behavior between layers while
preserving distinct materials requires duplicating objects.

Providing access to properties of layers and scenes via the attribute
node enables making materials with built-in switches or settings that
can be controlled globally at the view layer level. This is probably
most useful for complex NPR shading and compositing. Like with objects,
the node can also access built-in scene properties, like render resolution
or FOV of the active camera. Lookup is also attempted in World, similar
to how the Object mode checks the Mesh datablock.

In Cycles this mode is implemented by replacing the attribute node with
the attribute value during sync, allowing constant folding to take the
values into account. This means however that materials that use this
feature have to be re-synced upon any changes to scene, world or camera.

The Eevee version uses a new uniform buffer containing a sorted array
mapping name hashes to values, with binary search lookup. The array
is limited to 512 entries, which is effectively limitless even
considering it is shared by all materials in the scene; it is also
just 16KB of memory so no point trying to optimize further.
The buffer has to be rebuilt when new attributes are detected in a
material, so the draw engine keeps a table of recently seen attribute
names to minimize the chance of extra rebuilds mid-draw.

Differential Revision: https://developer.blender.org/D15941
2022-10-08 16:43:18 +03:00
2f7234d3e1 Attribute Node: access geometry node instance attributes.
The Instancer mode of the node is intended for varying material
behavior between instances. Since Geometry Nodes support arbitrary
named instance attributes, this mode should include them in lookup.

To implement this it is sufficient to store references to Geometry
Node data in DupliObject, and check it during dupli attribute lookup.

In order to reduce the memory usage of DupliObject, only 4 array
entries are allocated, even though the current dupli recursion stack
limit is 8. This assumes that not every entry would be associated with
a GeometrySet instance. Hopefully, soon the whole system will be
rewritten to remove the hard limits altogether.

Differential Revision: https://developer.blender.org/D16114
2022-10-03 18:02:24 +03:00
554afabf75 Attribute Node: refactor lookup to remove duplication between engines.
Currently lookup of Object and Instancer attributes is completely
duplicated between Cycles, Eevee and Eevee Next. This is bad design,
so this patch aims to deduplicate it by introducing a common API
in blenkernel.

In case of Cycles this requires certain hacks, but according to
Brecht it is planned to be rewritten later for more direct access
to internal Blender data anyway.

Differential Revision: https://developer.blender.org/D16117
2022-09-30 20:01:57 +03:00
a790873d2a Cleanup: Typo in forward declaration 2022-09-28 16:32:59 -05:00
c55d38f00b Geometry Nodes: viewport preview
This adds support for showing geometry passed to the Viewer in the 3d
viewport (instead of just in the spreadsheet). The "viewer geometry"
bypasses the group output. So it is not necessary to change the final
output of the node group to be able to see the intermediate geometry.

**Activation and deactivation of a viewer node**
* A viewer node is activated by clicking on it.
* Ctrl+shift+click on any node/socket connects it to the viewer and
  makes it active.
* Ctrl+shift+click in empty space deactivates the active viewer.
* When the active viewer is not visible anymore (e.g. another object
  is selected, or the current node group is exit), it is deactivated.
* Clicking on the icon in the header of the Viewer node toggles whether
  its active or not.

**Pinning**
* The spreadsheet still allows pinning the active viewer as before.
  When pinned, the spreadsheet still references the viewer node even
  when it becomes inactive.
* The viewport does not support pinning at the moment. It always shows
  the active viewer.

**Attribute**
* When a field is linked to the second input of the viewer node it is
  displayed as an overlay in the viewport.
* When possible the correct domain for the attribute is determined
  automatically. This does not work in all cases. It falls back to the
  face corner domain on meshes and the point domain on curves. When
  necessary, the domain can be picked manually.
* The spreadsheet now only shows the "Viewer" column for the domain
  that is selected in the Viewer node.
* Instance attributes are visualized as a constant color per instance.

**Viewport Options**
* The attribute overlay opacity can be controlled with the "Viewer Node"
  setting in the overlays popover.
* A viewport can be configured not to show intermediate viewer-geometry
  by disabling the "Viewer Node" option in the "View" menu.

**Implementation Details**
* The "spreadsheet context path" was generalized to a "viewer path" that
  is used in more places now.
* The viewer node itself determines the attribute domain, evaluates the
  field and stores the result in a `.viewer` attribute.
* A new "viewer attribute' overlay displays the data from the `.viewer`
  attribute.
* The ground truth for the active viewer node is stored in the workspace
  now. Node editors, spreadsheets and viewports retrieve the active
  viewer from there unless they are pinned.
* The depsgraph object iterator has a new "viewer path" setting. When set,
  the viewed geometry of the corresponding object is part of the iterator
  instead of the final evaluated geometry.
* To support the instance attribute overlay `DupliObject` was extended
  to contain the information necessary for drawing the overlay.
* The ctrl+shift+click operator has been refactored so that it can make
  existing links to viewers active again.
* The auto-domain-detection in the Viewer node works by checking the
  "preferred domain" for every field input. If there is not exactly one
  preferred domain, the fallback is used.

Known limitations:
* Loose edges of meshes don't have the attribute overlay. This could be
  added separately if necessary.
* Some attributes are hard to visualize as a color directly. For example,
  the values might have to be normalized or some should be drawn as arrays.
  For now, we encourage users to build node groups that generate appropriate
  viewer-geometry. We might include some of that functionality in future versions.
  Support for displaying attribute values as text in the viewport is planned as well.
* There seems to be an issue with the attribute overlay for pointclouds on
  nvidia gpus, to be investigated.

Differential Revision: https://developer.blender.org/D15954
2022-09-28 17:54:59 +02:00
c434782e3a File headers: SPDX License migration
Use a shorter/simpler license convention, stops the header taking so
much space.

Follow the SPDX license specification: https://spdx.org/licenses

- C/C++/objc/objc++
- Python
- Shell Scripts
- CMake, GNUmakefile

While most of the source tree has been included

- `./extern/` was left out.
- `./intern/cycles` & `./intern/atomic` are also excluded because they
  use different header conventions.

doc/license/SPDX-license-identifiers.txt has been added to list SPDX all
used identifiers.

See P2788 for the script that automated these edits.

Reviewed By: brecht, mont29, sergey

Ref D14069
2022-02-11 09:14:36 +11:00
4b1f243e4d Cleanup: sort struct forward declarations 2022-01-24 21:16:06 +11:00
ffc4c126f5 Cleanup: move public doc-strings into headers for 'blenkernel'
- Added space below non doc-string comments to make it clear
  these aren't comments for the symbols directly below them.
- Use doxy sections for some headers.
- Minor improvements to doc-strings.

Ref T92709
2021-12-07 17:38:48 +11:00
5a9a16334c Geometry Nodes: support for geometry instancing
Previously, the Point Instance node in geometry nodes could only instance
existing objects or collections. The reason was that large parts of Blender
worked under the assumption that objects are the main unit of instancing.
Now we also want to instance geometry within an object, so a slightly larger
refactor was necessary.

This should not affect files that do not use the new kind of instances.

The main change is a redefinition of what "instanced data" is. Now, an
instances is a cow-object + object-data (the geometry). This can be nicely
seen in `struct DupliObject`. This allows the same object to generate
multiple geometries of different types which can be instanced individually.

A nice side effect of this refactor is that having multiple geometry components
is not a special case in the depsgraph object iterator anymore, because those
components are integrated with the `DupliObject` system.

Unfortunately, different systems that work with instances in Blender (e.g.
render engines and exporters) often work under the assumption that objects are
the main unit of instancing. So those have to be updated as well to be able to
handle the new instances. This patch updates Cycles, EEVEE and other viewport
engines. Exporters have not been updated yet. Some minimal (not master-ready)
changes to update the obj and alembic exporters can be found in P2336 and P2335.
Different file formats may want to handle these new instances in different ways.

For users, the only thing that changed is that the Point Instance node now
has a geometry mode.

This also fixes T88454.

Differential Revision: https://developer.blender.org/D11841
2021-09-06 18:31:25 +02:00
91694b9b58 Code Style: use "#pragma once" in source directory
This replaces header include guards with `#pragma once`.
A couple of include guards are not removed yet (e.g. `__RNA_TYPES_H__`),
because they are used in other places.

This patch has been generated by P1561 followed by `make format`.

Differential Revision: https://developer.blender.org/D8466
2020-08-07 09:50:34 +02:00
bfc644dcfb Reduce DupliObject::persistent_id from 16 to 8 items
For historical reasons, `DupliObject::persistent_id` was of size
`2*MAX_DUPLI_RECUR`. These reasons are now gone, and the persistent ID
always gets exactly one array element for every dupli-recursion.

Differential Revision: https://developer.blender.org/D8222

Reviewed by: brecht
2020-07-06 16:52:28 +02:00
b5253159b6 Cleanup: split BKE_anim.h and anim.c into smaller pieces
The files are now split up into the following sections:
- `BKE_anim_path.h` and `anim_path.c` for path/curve functions.
- `BKE_anim_visualization.h` and `anim_visualizationanim_path.c` for
  animation visualization (mostly motion paths).
- `BKE_duplilist.h` for DupliList function declarations. These were
  already implemented in `object_dupli.c`, so they were rather out of
  place being declared in `BKE_anim.h` in the first place.

No functional changes.
2020-04-03 12:13:51 +02:00