The previous algorithm was not using all of the requested grids to build a mesh
around the volume due to limitations regarding the use of a dense buffer to
gather information about the volume's topology. This resulted in artefacts during
rendering.
The mesh generation is now done by merging all of the input grids and using the
resulting grid's topology to create the mesh. The generation of the mesh
is still done in index space as before, and the vertices are converted to object
space by using the merged topology grid indexToWorld transform.
To be able to merge the grids together we have to make sure that their transformation
matrices and their index spaces match, thus, if they do not match we simply resample
the grids. This behaviour should tackle one other limitation of the current algorithm,
which is that only one transformation matrix was used to generate the final mesh.
If we do not have an OpenVDB grid for the requested volume data, we generate
a temporary OpenVDB grid for it.
Differential Revision: https://developer.blender.org/D8401
In an upcoming bugfix we'll use OpenVDB data structures directly to build mesh
for sparse OpenVDB volumes, loading them OpenVDB grids earlier and removing any
references to Blender data structures makes that easier.
This also makes changes to Blender volumes to support this, so Cycles can take
ownership of a grid without Blender having to keep its own reference to it.
This should also be useful in a future Python API.
Ref D8401
Rather than passing around void pointers, various Blender image sources now
subclass this. OIIO is also just another type of image loader.
Also fixes T67718: Cycles viewport render crash editing point density settings
This patch contains the work that I did during my week at the Code Quest - adding support for tiled images to Blender.
With this patch, images now contain a list of tiles. By default, this just contains one tile, but if the source type is set to Tiled, the user can add additional tiles. When acquiring an ImBuf, the tile to be loaded is specified in the ImageUser.
Therefore, code that is not yet aware of tiles will just access the default tile as usual.
The filenames of the additional tiles are derived from the original filename according to the UDIM naming scheme - the filename contains an index that is calculated as (1001 + 10*<y coordinate of the tile> + <x coordinate of the tile>), where the x coordinate never goes above 9.
Internally, the various tiles are stored in a cache just like sequences. When acquired for the first time, the code will try to load the corresponding file from disk. Alternatively, a new operator can be used to initialize the tile similar to the New Image operator.
The following features are supported so far:
- Automatic detection and loading of all tiles when opening the first tile (1001)
- Saving all tiles
- Adding and removing tiles
- Filling tiles with generated images
- Drawing all tiles in the Image Editor
- Viewing a tiled grid even if no image is selected
- Rendering tiled images in Eevee
- Rendering tiled images in Cycles (in SVM mode)
- Automatically skipping loading of unused tiles in Cycles
- 2D texture painting (also across tiles)
- 3D texture painting (also across tiles, only limitation: individual faces can not cross tile borders)
- Assigning custom labels to individual tiles (drawn in the Image Editor instead of the ID)
- Different resolutions between tiles
There still are some missing features that will be added later (see T72390):
- Workbench engine support
- Packing/Unpacking support
- Baking support
- Cycles OSL support
- many other Blender features that rely on images
Thanks to Brecht for the review and to all who tested the intermediate versions!
Differential Revision: https://developer.blender.org/D3509
This also replaces the Use Alpha setting. We now have these alpha modes:
* Straight: store RGB and alpha channels separately with alpha acting as a
mask, also known as unassociated alpha.
* Premultiplied: transparent RGB pixels are multiplied by the alpha channel.
The natural format for renders.
* Channel Packed: different images are packed in the RGB and alpha channels,
and they should not influence each other. Channel packing is commonly used
by game engines to save memory.
* None: ignore alpha channel from the file and make image fully opaque.
Cycles OSL does not correctly support Channel Packed and None yet, we are
missing fine control over the OpenImageIO texture cache to do that.
Fixes T53672
A better solution would be to not use the callback mechanism anymore for
cases like this where the dependency graph will free volume data, but
that would be a bigger refactor.
These are the internal changes to Cycles, for Blender integration there are no
functional changes in this commit.
Images are converted to scene linear color space on file load, and on reading
from the OpenImageIO texture cache. 8-bit images are compressed with the sRGB
transfer function to avoid precision loss while keeping memory usages low. This
also means that for common cases of 8-bit sRGB images no conversion happens at
all on image loading.
Initial patch by Lukas, completed by Brecht.
Differential Revision: https://developer.blender.org/D3491
There are some changes in API of OpenImageIO, but those are quite
simple to keep working with older and newer library versions.
Reviewers: brecht
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D4064
Gathers information about object geometry and textures. Very basic at
this moment, but need to start somewhere.
Things which needs to be included still:
- "Runtime" information, like BVH. While it is not directly controllable
by artists, it's still important to know.
- Device array sizes. Again, not under artists control, but is added to
the overall size.
- Memory peak at different synchronization stages.
At this point it simply prints info to the stdout after F12 is done,
need better control over that too.
Reviewers: brecht
Differential Revision: https://developer.blender.org/D3566
There is no reason or justification to have helper functions as
class methods: they do not depend on anything in the class itself.
There are probably more cases like that.
Textures in 16 bit integer format are sometimes used for displacement, bump and normal maps and can be exported by tools like Substance Painter. Without this patch, Cycles would promote those textures to single precision floating point, causing them to take up twice as much memory as needed.
Reviewers: #cycles, brecht, sergey
Reviewed By: #cycles, brecht, sergey
Subscribers: sergey, dingto, #cycles
Tags: #cycles
Differential Revision: https://developer.blender.org/D3523
The automatic mode checks all Enviroment Texture nodes and picks the largest image's resolution.
If there are no Enviroment Textures, it just uses the old default.
Also, the sampling map now isn't limited to square shapes. The automatic detection uses the exact image size,
the manual UI option now halves the value to get the height.
A default aspect ratio of 2:1 makes sense since this is what most HDRIs use.
Reviewers: brecht, sergey
Differential Revision: https://developer.blender.org/D3477
With copy-on-write we can no longer assumes the point density data is
available after Cycles synchronization with Blender data is done. So
force it to be loaded earlier, even if it's not great for interactivity.
around the volume.
We generate a tight mesh around the active voxels of the volume in order
to effectively skip empty space, and start volume ray marching as close
to interesting volume data as possible. See code comments for details on
how the mesh generation algorithm works.
This gives up to 2x speedups in some scenes.
Reviewed by: brecht, dingto
Reviewers: #cycles
Subscribers: lvxejay, jtheninja, brecht
Differential Revision: https://developer.blender.org/D3038
