This commit adds a new model to the Sky Texture node, which is based on a
method by Nishita et al. and works by basically simulating volumetric
scattering in the atmosphere.
By making some approximations (such as only considering single scattering),
we get a fairly simple and fast simulation code that takes into account
Rayleigh and Mie scattering as well as Ozone absorption.
This code is used to precompute a 512x128 texture which is then looked up
during render time, and is fast enough to allow real-time tweaking in the
viewport.
Due to the nature of the simulation, it exposes several parameters that
allow for lots of flexibility in choosing the look and matching real-world
conditions (such as Air/Dust/Ozone density and altitude).
Additionally, the same volumetric approach can be used to compute absorption
of the direct sunlight, so the model also supports adding direct sunlight.
This makes it significantly easier to set up Sun+Sky illumination where
the direction, intensity and color of the sun actually matches the sky.
In order to support properly sampling the direct sun component, the commit
also adds logic for sampling a specific area to the kernel light sampling
code. This is combined with portal and background map sampling using MIS.
This sampling logic works for the common case of having one Sky texture
going into the Background shader, but if a custom input to the Vector
node is used or if there are multiple Sky textures, it falls back to using
only background map sampling (while automatically setting the resolution to
4096x2048 if auto resolution is used).
More infos and preview can be found here:
https://docs.google.com/document/d/1gQta0ygFWXTrl5Pmvl_nZRgUw0mWg0FJeRuNKS36m08/view
Underlying model, implementation and documentation by Marco (@nacioss).
Improvements, cleanup and sun sampling by @lukasstockner.
Differential Revision: https://developer.blender.org/D7896
This patch makes the infamous "Cancel" error in the viewport a thing of the past. Instead it
now shows a more useful error message and streamlines the error handling process in CUDA.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D8008
Steam just released a SteamVR update with OpenXR Developer Preview
support:
https://steamcommunity.com/games/250820/announcements/detail/2396425843528787270.
Once SteamVR is set up for OpenXR (see link above), it works with
Blender "out of the box", thanks to OpenXR!
We have to apply the sRGB transform workaround for SteamVR though,
otherwise it renders way too dark. Done in the next commit.
Note that AMD users may still only see a pink screen, because the
OpenGL-DirectX compatibility fails. I will check on a fix again.
For SteamVR on Linux we may have to wait for until it supports OpenGL
rendering for OpenXR. Alternatively, we *could* add initial Vulkan
support at Ghost level and use Vulkan<->OpenGL interoperability
extensions, Monado uses these as well.
When closing the File Browser window after making it fullscreen, Blender would
either crash or all windows would disappear, with no obvious way to bring them
back.
The "fix" is to not allow fullscreen for File Browsers (or any future "dialog"
windows), but only maximizing. From what I can tell that's how secondary
windows are supposed to work on macOS. What we previously did seemed like
something macOS doesn't handle cleanly, and I didn't find a simple way to do so
on our side.
With this patch Cycles recognizing when a logical OptiX and CUDA device represent the same
physical GPU and attempts to eliminate unnecessary tile copies for viewport rendering if that
is the case for all active devices. In addition, denoising is now no longer performed on the first
available OptiX device only, but instead it will try to match CUDA and OptiX
rendering/denoising devices exactly to maximize utilization.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D7975
This code is currently only used for the Glossy Toon BSDF, but it's a generic
building block that might be used for other things in the future.
To see why the current code does not give a uniform distribution, consider that
it chooses both angles uniformly, but the smaller the angle from the center of
the cone is, the smaller the differential solid angle is (similar to how
sampling disks by choosing radius and phi uniformly does not work).
Differential Revision: https://developer.blender.org/D7948
This change modifies the multi-device implementation to support memory distribution
across devices, to reduce the overall memory footprint of large scenes and allow scenes to
fit entirely into combined GPU memory that previously had to fall back to host memory.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D7426
This reverts commit 33ce0cb5a1.
Fix T77273: crash enabling portal lights. The optimization for background
updates can be added back later for 2.90 and 2.83.1.
This remove the complexity of queriying the locations at runtime and
allows for more performance and upfront binding specifications.
The benefit of doing everything at creation time is that we can assign binding
points in a predictable order which is going to be somewhat the same for
every similar shader.
This also rewrite GPU_vertformat_from_shader to not use shaderface.
This is to keep the shaderface simple. If it becomes necessary to not query
the shader after creation (i.e: vulkan?) we could just create the vert
format in advance at compilation for PyGPU shaders.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D7879
A new user parameter can be used to shift the shadow terminator
towards the light source. With it, one can hide some of the
artifacts that appear on coarse meshes with smooth shading.
Note that this technique is not engery conserving.
This is based on the work by the Appleseed renderer team.
Differential Revision: https://developer.blender.org/D7634
The input data to the OptiX denoiser was clamped to 0..10000 as required, but it could easily
exceed that range with a high number of samples (since the data contains the overall sum). To
fix that, divide by the number of samples first and multiply it back in after the denoiser ran.
This change makes it so vertices of edge are only stored when edge
has non-zero crease. This allows to lower memory footprint of 1.5M
faces from 78 MiB to 54 MiB in the case all creases are zero.
Meshes with crease are more hard to predict due to array-based
storage, so it all depends on index of edge with crease. Worst case
(all edges are creased) still stays at 78 MiB.
Makes it possible to set adjacent vertices after edge sharpness.
Initially it seemed like useful sanity check, but with time it
became rather a burden.
Avoid per-face pointer and allocation: store everything as continuous
arrays.
Memory footprint for 1.5M faces:
- Theoretical worst case (all vertices and edges have crease) memory
goes down from 114 MiB to 96 MiB (15% improvement).
This case is not currently achievable since Blender does not expose
vertex crease yet.
- Current real life worst case (all edges have crease) memory goes
down from 108 MiB to 90 MiB (17% improvement).
- Best case (no creases at all) memory goes down from 96 MiB to 78 MiB
(19% improvement).
While this looks trivial it already allowed to catch issues in one
of previous attempt to optimize memory usage. It will totally be
useful for an upcoming refactor of face topology storage.
Allows to perform comparison by doing linear comparison of indices.
Before cyclic match was used to deal with possibly changed winding from
OpenSubdiv side.
Speeds up comparison (and hence improves FPS), makes code more reliable
nut uses more memory.
