* New experimental tone mapper
The new tone mapper proposed in this change replaces Uchimura (see
below) and is composed of two distinct algorithms:
- The first is the customizable compression curve from Timothy Lotte
(from GDC 2015). The curve's default parameters were chosen to
match the overall appearance (contrast) of the ACES curves used
as our current default tone mapper. This was done to provide a
good migration path to making this new solution the default in
a future version of Filament.
The compression curve can be customized via its contrast, shoulder,
input middle gray, output middle gray, and maximum "HDR value"
(scene referred).
It is important to note that the compression is only applied to
the luminance of the input scene referred value.
- The second is a novel approach by Troy Sobotka called Exposure
Value Invariant Luminance Scaling (or EVILS). This solution works
on the largest chromatic channel of the input value as opposed
to mapping all RGB channels as we do in our other tone mappers.
The algorithm effectively scales all channel by a ratio that
depends on both the compressed luminance from the first stage
and the luminance of input value normalized by the largest
channel.
This new solution offers important benefits as it manages to
preserve chromaticity for high input values. It is also designed
to provide a desirable rolloff to white on overexposure. This
means that even without gamut mapping, this solution avoids many
hue skews (red to orange, blue to purple, etc.). The results
provided by this solution are much more natural and make using
other color grading tools much easier.
* Use std::pow instead of pow
* Fix Web builds
New Api:
- Renderer::renderStandaloneView() is a new method that can be used
outside of beginFrame/endFrame on Views that have a RenderTarget
associated. This can be used as a poor man's compute API.
Improvements to Renderer:
- more aggressively skip lighting/shadowing code that won't be
needed by the current view
- Allow up to 64 KiB to be allocated from the render stream, up from
1 KiB
Just for fun, this is an example of a web component that allows you to
embed a Filament viewer with a single HTML element. It does not have
many features, but is much easier to use than our raw JavaScript API.
We now annotate the JS wrapper for Engine with a GL context handle.
This is fairly hacky because emscripten hides its internal GL object
from JavaScript, and it does not provide a mechanism to pass JS objects
into inline assembly.
NOTE: after Metal and Vulkan support lands, we can potentially simplify
the Driver API by removing some of the old VertexBuffer entry points.
This introduces a new API-level object called `BufferObject`, and a new
backend-level object called `HwBufferObject`. This encapsulates a single
VBO. It's especially useful when clients need to share data between
multiple VertexBuffer objects. (e.g. for morphing).
In the future, buffer objects could perhaps be used for non-vertex data
(e.g. for compute).
The existing `VertexBuffer` class can now be configured to use buffer
objects by calling `enableBufferObjects` on the builder. By default its
API is unchanged. If buffer objects are enabled, then clients should use
`setBufferObjectAt` (which takes a buffer object) rather than
`setBufferAt` (which takes CPU data).
OpenGL is the trickiest backend for this, due to existence of VAOs.
The implementation in this PR uses a version-tracking scheme to
figure out when to update the VAO.
* move the focus distance from DofOptions to Camera
The DofOption parameter is now deprecated, but will still work if the
focus distance is not set on Camera.
* A few new helper APIs on Camera
- getFocalLength() which returns the focal length used internally for
DoF computations.
- computeEffectiveFov() and computeEffectiveFocalLength() which can be
used to better simulate a real camera's FOV changes with the
focus distance.
Modified gltf_viewer so it uses the effective fov/focallendth when
DoF is active.
* simplify setLensProjection
We can call setProjection directly instead of converting to a fov
first, which ends up performing atan(tan(x)).
Also improve parameters names.
Currently the only NONE and MEDIAN are available options, at some
point we may add a "MAX" option which is cheaper.
There is no real practical uses for this option with these only two
choices, other than for debugging.
