* Materials can now provide custom lighting/shading
When a material uses the "lit" shading model, customSurfaceShading can
be enabled to replace Filament's lighting implementation. When this
feature is enabled, the material *must* provide the following function
in the fragment shader block:
vec3 surfaceShading(
const MaterialInputs materialInputs,
const ShadingData shadingData,
const LightData lightData
) {
return vec3(1.0); // custom lighting here
}
Please refer to the docs in Materials.html for more information about
this feature and the different values provided by the data structures
passed to the function.
* Update docs
* Update docs/Materials.md.html
Co-authored-by: Philip Rideout <philiprideout@gmail.com>
Co-authored-by: Philip Rideout <philiprideout@gmail.com>
If expecting a bool and receiving anything other than true or false,
this is invalid and should fail. This change triggered a unit test
failure which uncovered several actual problems.
We used to have that before, but it was hardcoded and depended on
mobile vs. desktop.
With this change, users can set the quality on the material itself.
The default match the current settings. There are 3 quality levels:
low: enables optimization that might not be 100% correct
(e.g. abs(x) instead of sqrt(x*x))
normal: like low, but doesn't sacrifices correctness.
high: could be improved upsampling, etc...
* 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
This will allow folks to drop a GLB into the following page to get a
WebGL preview. It always uses the latest version of Filament via unpkg.
https://google.github.io/filament/viewer
After the next release we can also use the `<filament-viewer>` component
itself from unpkg and remove the local copy.
This script makes it easy to update the web page at
https://google.github.io/filament/remote/ even if you do not have the
emscripten SDK. It works by downloadinug the latest continuous web
build, then placing the wasm file in the right place.
After running the script, the user must make a git commit to finish the
operation.
Shockingly there were no unit tests that did a simple write-then-read.
This is important because it's easy to forget details such as trailing
commas and the fact that uint8_t is a char.
* Add support for sheenColor and sheenRoughness
This work is necessary to support the glTF extension KHR_materials_sheen.
This change effectively adds the specular lobe from the cloth material
model to the base material model. The cloth model remains useful for
its extra subsurface color feature but also because it's cheaper.
* Add support for KHR_materials_sheen to gltfio
* Update documentation
* Document default shading values
.blurScale was in fact a scale factor applied to the circle of
confusion (which makes it indeed a "blur scale", but let's use
a more precise language here).
Update comments to show how to use .cocScale to control the DoF
effect independently from the camera aperture, which can be useful for
artistic reasons.
