* Space: volume density and step size in object or world space
* Step Size: override automatic step size
* Clipping: values below this are ignored for tighter volume bounds
The last two are Cycles only currently.
Ref T73201
By default it will now set the step size to the voxel size for smoke and
volume objects, and 1/10th the bounding box for procedural volume shaders.
New settings are:
* Scene render/preview step rate: to globally adjust detail and performance
* Material step rate: multiplied with auto detected per-object step size
* World step size: distance to steo for world shader
Differential Revision: https://developer.blender.org/D1777
Voxels are loaded directly from the OpenVDB grid. Rendering still only supports
dense grid, so memory usage is not great for sparse volumes, this is to be
addressed in the future.
Ref T73201
NOTE: While most of the milestone 1 goals are there, a few smaller features and
improvements are still to be done.
Big picture of this milestone: Initial, OpenXR-based virtual reality support
for users and foundation for advanced use cases.
Maniphest Task: https://developer.blender.org/T71347
The tasks contains more information about this milestone.
To be clear: This is not a feature rich VR implementation, it's focused on the
initial scene inspection use case. We intentionally focused on that, further
features like controller support are part of the next milestone.
- How to use?
Instructions on how to use this are here:
https://wiki.blender.org/wiki/User:Severin/GSoC-2019/How_to_Test
These will be updated and moved to a more official place (likely the manual) soon.
Currently Windows Mixed Reality and Oculus devices are usable. Valve/HTC
headsets don't support the OpenXR standard yet and hence, do not work with this
implementation.
---------------
This is the C-side implementation of the features added for initial VR
support as per milestone 1. A "VR Scene Inspection" Add-on will be
committed separately, to expose the VR functionality in the UI. It also
adds some further features for milestone 1, namely a landmarking system
(stored view locations in the VR space)
Main additions/features:
* Support for rendering viewports to an HMD, with good performance.
* Option to sync the VR view perspective with a fully interactive,
regular 3D View (VR-Mirror).
* Option to disable positional tracking. Keeps the current position (calculated
based on the VR eye center pose) when enabled while a VR session is running.
* Some regular viewport settings for the VR view
* RNA/Python-API to query and set VR session state information.
* WM-XR: Layer tying Ghost-XR to the Blender specific APIs/data
* wmSurface API: drawable, non-window container (manages Ghost-OpenGL and GPU
context)
* DNA/RNA for management of VR session settings
* `--debug-xr` and `--debug-xr-time` commandline options
* Utility batch & config file for using the Oculus runtime on Windows.
* Most VR data is runtime only. The exception is user settings which are saved
to files (`XrSessionSettings`).
* VR support can be disabled through the `WITH_XR_OPENXR` compiler flag.
For architecture and code documentation, see
https://wiki.blender.org/wiki/Source/Interface/XR.
---------------
A few thank you's:
* A huge shoutout to Ray Molenkamp for his help during the project - it would
have not been that successful without him!
* Sebastian Koenig and Simeon Conzendorf for testing and feedback!
* The reviewers, especially Brecht Van Lommel!
* Dalai Felinto for pushing and managing me to get this done ;)
* The OpenXR working group for providing an open standard. I think we're the
first bigger application to adopt OpenXR. Congratulations to them and
ourselves :)
This project started as a Google Summer of Code 2019 project - "Core Support of
Virtual Reality Headsets through OpenXR" (see
https://wiki.blender.org/wiki/User:Severin/GSoC-2019/).
Some further information, including ideas for further improvements can be found
in the final GSoC report:
https://wiki.blender.org/wiki/User:Severin/GSoC-2019/Final_Report
Differential Revisions: D6193, D7098
Reviewed by: Brecht Van Lommel, Jeroen Bakker
Extends Ghost to include an abstraction for OpenXR, which I refer to as
Ghost-XR. Such an API is the base for the following commit, which introduces VR
support to Blender.
Main features:
* Simple and high-level interface for Blender specific code to call.
* Extensible for muliple graphics backends, currently OpenGL and a DirectX
compatibility layer are supported.
* Carefully designed error handling strategy allowing Blender to handle errors
gracefully and with useful error messages.
* OpenXR extension and API-layer management.
* OpenXR session management.
* Basic OpenXR event management.
* Debug utilities for Ghost-XR and OpenXR
For more information on this API, check
https://wiki.blender.org/wiki/Source/Interface/XR.
Reviewed by: Brecht Van Lommel
Differential Revision: https://developer.blender.org/D6188
Allow to mark individual vertices as infinitely sharp even if there is
no full topology and no access to edges: infinite sharp vertices do not
need connectivity information.
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 is mostly straightforward, but required some refactoring to ensure that
the default volume material does not always turn on the volume feature for GPU
rendering.
This is more in line with standard grids and means we don't have to make
many special exceptions in the upcoming change for arbitrary number of volume
grids support in Eevee.
The workbench shader was also changed to fix bugs where squared density was
used, and the smoke color would affect the density so that black smoke would
be invisible. This can change the look of smoke in workbench significantly.
When using the color grid when smoke has a constant color, the color grid
will no longer be premultiplied by the density. If the color is constant
we want to be able not to store a grid at all. This breaks one test for
Cycles and Eevee, but the setup in that test using a color without density
does not make sense. It suffers from artifacts since the unpremultiplied
color grid by itself will not have smooth boundaries.
Differential Revision: https://developer.blender.org/D6951
