Blender grid rendering interprets voxel transforms in such a way that the voxel
values are located at the center of a voxel. This is inconsistent with OpenVDB
where the values are located at the lower corners for the purpose or sampling
and related algorithms.
While it is possible to offset grids when communicating with the OpenVDB
library, this is also error-prone and does not add any major advantage.
Every time a grid is passed to OpenVDB we currently have to take care to
transform by half a voxel to ensure correct sampling weights are used that match
the density displayed by the viewport rendering.
This patch changes volume grid generation, conversion, and rendering code so
that grid transforms match the corner-located values in OpenVDB.
- The volume primitive cube node aligns the grid transform with the location of
the first value, which is now also the same as min/max bounds input of the
node.
- Mesh<->Grid conversion does no longer require offsetting grid transform and
mesh vertices respectively by 0.5 voxels.
- Texture space for viewport rendering is offset by half a voxel, so that it
covers the same area as before and voxel centers remain at the same texture
space locations.
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/138449
This PR adds a slip tool in the toolbar with its own custom icon for
applying slips using the mouse. This is useful for e.g. tablets where a
keyboard is not handy and a button would be best to activate the
operator.
There is also a custom cursor that appears when hovering over valid,
slippable strips (and a "stop" icon when the strip cannot be slipped).
Alt may be used in order to ignore slipping connected strips when using
the tool, similar to selection logic. The slip tool only performs its
sole function of slipping and as such does not change the selection
state.
In the future, we can also add "slide" functionality to the same tool,
giving it multiple functions.
Pull Request: https://projects.blender.org/blender/blender/pulls/143513
Supports baking to object and tangent space.
Compatible with Cycles Vector Displacement node which has the
(tangent, normal, bitangent) convention.
The viewport situation is a bit confusing: seems that Eevee
does not handle vector displacement properly and rips all faces
apart. Cycles renders the displaced object correctly.
Not entirely happy with the UI, as displacement space does not
really belong to the Output, but so doesn't Low Resolution Mesh.
Perhaps the best would be to have a separate pass to revisit the
settings, and also make it more clear what the Low Resolution Mesh
actually does.
Pull Request: https://projects.blender.org/blender/blender/pulls/145014
Almost all settings were duplicated between BakeData and RenderData.
The only missing field was the bake type, which is stored as a custom
property in Cycles.
This change:
- Removes unused bake_samples and bake_biasdist.
- Migrates settings like bake_margin to BakeData.
- Switches multires baker to use bake_margin.
- Introduces bake type in the BakeData, the same way how it was
defined in RenderData::bake_mode.
Pull Request: https://projects.blender.org/blender/blender/pulls/144984
The main idea is to switch Bake from Multires from legacy DerivedMesh
to Subdiv. On the development side of things this change removes a lot
of code, also making it easier easier to rework CustomData and related
topics, without being pulled down by the DerivedMesh.
On the user level switch to Subdiv means:
- Much more closer handling of the multi-resolution data: the derived
mesh code was close, but not exactly the same when it comes to the
final look of mesh.
Other than less obvious cases (like old DerivedMesh approach doing
recursive subdivision instead of pushing subdivided vertices on the
limit surface) there are more obvious ones like difference in edge
creases, and non-supported vertex creases by the DerivedMesh.
- UV interpolation is done correctly now when baking to non-base level
(baking to multi-resolution level >= 1).
Previously in this case the old derived mesh interpolation was used
to interpolate face-varying data, which gives different results from
the OpenSubdiv interpolation.
- Ngon faces are properly supported now.
A possible remaining issue is the fact that getting normal from CCG
always uses smooth interpolation. Based on the code it always has been
the case, so while it is something to look into it might be considered
a separate topic to dig into.
This PR adds HDR support for Windows for `VK_COLOR_SPACE_EXTENDED_SRGB_LINEAR_EXT`
on `VK_FORMAT_R16G16B16A16_SFLOAT` swapchains .
For nonlinear surface formats (sRGB and extended sRGB) the back buffer is blit into the swapchain,
When VK_COLOR_SPACE_EXTENDED_SRGB_LINEAR_EXT is used as surface format a compute shader
is used to flip and invert the gamma.
SDR white level is updated from a few window event changes, but actually
none of them immediately respond to SDR white level changes in the system.
That requires using the WinRT API, which we don't do so far.
Current limitations:
- Intel GPU support
- Dual GPU support
In the future we may add controls inside Blender for absolute HDR nits,
across different platforms. But this makes behavior closer to macOS.
See !144565 for details
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/144717
`world_use_portal` is not needed anymore, now that we always add world
as object (b20b4218d5).
We now check if background light is enabled only in
`test_enabled_lights()`, depending on the sample settings.
Pull Request: https://projects.blender.org/blender/blender/pulls/144710
It works with the beta we are using to build Blender 4.5, but the official
release is a bit different. This fix was tested to work with OSL 1.14.7.
Thanks to Paul Zander for finding the OSL commit that lead to this.
Pull Request: https://projects.blender.org/blender/blender/pulls/144715
First advance to the next frame and use the same index for all
resources. Previous implementation used a fence of the next frame, what
added confusion why that was actually needed.
Should not make a change in functionality or performance.
Pull Request: https://projects.blender.org/blender/blender/pulls/144615
Blender had some support for using MoltenVK. However there are some key
issues why MotlenVK cannot be used. Bugs have been reported up-stream.
As it doesn't work and holds back regular developments it will be removed
from the main branch.
Any efforts on making Vulkan run on Apple (including KosmicKrisp)
is considered a community effort and can be done in a development
branch.
Pull Request: https://projects.blender.org/blender/blender/pulls/144602
It has ~1.2x speed-up on CPU and ~1.5x speed-up on GPU (tested on Metal
M2 Ultra).
Individual samples are noisier, but equal time renders are mostly
better.
Note that volume emission renders differently than before.
Pull Request: https://projects.blender.org/blender/blender/pulls/144451
Currently, it was discovered that in the case of several different
Intel dGPUs being present in the system, the experimental L0 copy
optimization does not work correctly in the Intel Driver, which is
causing crashes in the driver and Blender application. So, to avoid
this situation and restore functionality on these platforms,
a workaround was added to disable this extension from being used if
such a configuration is detected. In the future, when this problem is
fully fixed in all Intel Drivers, this workaround can be removed from
the Blender source code to restore some performance that was lost on
configurations of several dGPUs because of this workaround.
Pull Request: https://projects.blender.org/blender/blender/pulls/144262
A constructor of the MANTA() constructor is only default-initializing
some of the fields, while initializeRNAMap() access to all of the fields,
causing access to uninitialized variables.
For example, mResXMesh is only initialized within some conditions about
mUsingLiquid and mUsingMesh but is always used to set value in the map.
Additionally fixed re-reference of iterator which equals to end(): the
iterator in such case does not contain value and it should not be accessed.
Pull Request: https://projects.blender.org/blender/blender/pulls/144502
Add a command line argument --gpu-vsync on/off/auto.
Prefer command line arguments for GPU settings,
as it means the value is error checked and set when Blender starts.
Also refactor GHOST_Context to take a parameter argument which
includes the stereo-visual & debug arguments and includes the newly
added vsync setting. This makes it possible to add GPU context
parameters more easily in the future.
It also removes redundant parsing & setting the VSync setting for
off-screen contexts.
Changes to recent PR !143049.
Ref !144473
Guide the probability to scatter in or transmit through the volume.
Only applied for primary rays.
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
The distance sampling is mostly based on weighted delta tracking from
[Monte Carlo Methods for Volumetric Light Transport Simulation]
(http://iliyan.com/publications/VolumeSTAR/VolumeSTAR_EG2018.pdf).
The recursive Monte Carlo estimation of the Radiative Transfer Equation is
\[\langle L \rangle=\frac{\bar T(x\rightarrow y)}{\bar p(x\rightarrow
y)}(L_e+\sigma_s L_s + \sigma_n L).\]
where \(\bar T(x\rightarrow y) = e^{-\bar\sigma\Vert x-y\Vert}\) is the
majorant transmittance between points \(x\) and \(y\), \(p(x\rightarrow
y) = \bar\sigma e^{-\bar\sigma\Vert x-y\Vert}\) is the probability of
sampling point \(y\) from point \(x\) following exponential
distribution.
At each recursive step, we randomly pick one of the two events
proportional to their weights:
* If \(\xi < \frac{\sigma_s}{\sigma_s+\vert\sigma_n\vert}\), we sample
scatter event and evaluate \(L_s\).
* Otherwise, no real collision happens and we continue the recursive
process.
The emission \(L_e\) is evaluated at each step.
This also removes some unused volume settings from the UI:
* "Max Steps" is removed, because the step size is automatically specified
by the volume octree. There is a hard-coded threshold `VOLUME_MAX_STEPS`
to prevent numerical issues.
* "Homogeneous" is automatically detected during density evaluation
An option "Unbiased" is added to the UI. When enabled, densities above
the majorant are clamped.
Due to numerical issues this was creating many wrong self-overlapping.
It was necessary for skipping empty regions, but not any more with the
volume Octree approach
