Bring color grading back into the Rec.709 color space to match
previous behaviors. This change also implements an exact inverse
tone map function for the "Filmic" operator.
This helps prevent over-darkening but it's an artistic hack.
We need to check how we compute the bent normals as it seems we
find occlusion where there is no occlusion. The effect is
particularly visible on clear coat materials like a car's body.
* Add support for transparent shadows
This solution uses an 8x8 Bayer matrix. We could find a better
noise. We also need better filtering of the shadow maps. A PCF
is barely enough and VSM fails without blurring.
* Use a fixed Bayer matrix, fix pre-caching of depth shaders
* Use gradient noise instead of fixed bayer pattern
* Update docs
* 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>
* 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
Emissive was previously defined in exposure compensation stops, which
was confusing to many. It is now a value in nits, with the alpha
channel controlling how much the camera exposure affects the emissive.
At 0, the emissive value is just added to the final pixel color, at
1 the emissive value is multiplied by the exposure just like with
regular lights.
The intensity of the emissive property can be computed from an
exposure value (EV) easily with the following formula:
emissive.rgb = emissive.rgb * pow(2.0, EV - 3.0);
This formula is available as Exposure::luminance(float) already
in Filament.
The user can now choose amongst 3 specular AO methods:
- None, specAO is off
- Simple, specAO is inferred from roughness and diffuse AO
- Bent normals, specAO is computed accurately from cone intersections
The last method is more expensive but produces the best results.
This change also fixes a few issues:
- Rename materialRefraction() and materialRefractionType() for
consistency
- Fixes user time in shaders
* Add the ability to modify clip space coordinates in the vertex shader
This introduces MaterialVertexInputs.clipSpaceTransform, a mat4 that
is applied to gl_Position before exiting the vertex stage.
* Address code review comments
* Improve materials under white furnace test
Two major changes:
- Mobile target now implements a cheaper variant of the off specular
peak bias (which moves the reflected vector towards the normal).
This greatly helps with rough surfaces that may otherwise point
toward a bright part of the IBL.
- The indirect diffuse love is now properly attenuated to avoid adding
the energy reflected by the specular layer. This allows dielectrics
to be correctly energy conserving under a white furnace.
- Tweak the (hacky) clear coat layer attenuation to behave properly
under a white furnace.
* Use the same reflected vector modification everywhere
* Add screen and multiply blending modes
This change also fixes a sorting issue: different sorting modes
were sorted in different buckets which is incorrect. We want
to sort only by distance.
* Update release notes and Java API
* Fix build error
This replaces the previous "curvature to roughness" method. Both are related
and rely on the screen space variance of geometric normals but this new
solution offers more control (the screen space variance and the clamping
threshold can be controlled).
