By removing the Fresnel term (often ommitted from fabric/cloth BRDFs)
we can store the DG term for the cloth BRDF in the 3rd channel of the
existing DFG LUT.
this adds a new --type (-t) parameter that is
used to specify cmgen’s output.
faces: outputs cube maps separate faces (default
and current behavior)
equirect: outputs an equirectangular image
ktx: outputs a ktx file
--format=ktx now implies —type=ktx
- internal cross storage is now always horizontal
and seamless.
- source cross images are now always converted to
internal format, conversion includes rescaling
and sampling if scaling down.
- vertical cross is supported again
- fixes#283
- replace hardcoded constants
- front and back labels where inverted:
+z is the front of the cube and -z is its back
when looking at the cube from the outside
with a camera pointing towards -z (and the cube
in front of it). This is the GL definition.
- make the synthetic uvXXX debug environment
colors match those of the debug environment
(except for -Z/back which is magenta instead
of black).
- add some documentation about skybox and cube map.
- cmgen now creates reflections maps for all input
assets by default instead of just for equirectangular
images.
- equirectangular decode doesn't mirror -- that's
done by the mirroring code now.
- mirroring can be turned of with --no-mirror
- option --mirror is gone
- faster mirroring code (do it before generating
mipmaps)
- added labels to faces of debug.png environment
- added a debug equirectangular image in third_party
(creative commons license)
- KTX / OpenGL are PX,NX,PY,NZ,PZ,NZ.
- Cubemap::Face is NX,PX,NY,PY,NZ,PZ.
I considered changing the Cubemap::Face enum, but applying ^1 upon
export seems less intrusive.
For each envmap/skybox pair, this will reduce the number of downloads
from 61 files to 3 files.
Note that we are still using sh.txt for coefficients, I'll see if it
would be easy to embed that in the KTX metadata.
Also, I will add KTX support to roughness-prefilter soon.
This remapping can be confused with roughness, because
linear_roughness = roughness*roughness and
lod = sqrt(linear_roughness)
so the value of lod is roughness, but conceptually
it’s not.
f90=0, which is nonsensical.
We now assume f0=f90=1, meaning the fresnel term
always evaluates to 1.
Thankfully this didn’t impact the prefilter too much.
IBLs MUST BE REGENERATED
* better comments on calculating the DFG lookup tables
* add comments about computing the “LD” term
* add comments about computing IBL diffuse pre-integration
* be clearer about the determinant of the jacobian
this saves one multiply in the shader, but most
importantly makes the first SH coefficient a
color and reduces its range
ALL IBLs NEED TO BE REGENERATED using cmgen
-—ibl-irradiance generates the diffuse irradiance as
a cubemap using importance sampling.
It can be used in place of the SH version (—-sh-irradiance)
which sometimes presents some ringing artifacts.
