filament/tools/cmgen

cmgen

cmgen is a command-line tool for generating SH and mipmap levels from an env map. Cubemaps and equirectangular formats are both supported, automatically detected according to the aspect ratio of the source image.

The tool can consume a HDR environment map in latlong format (equirectilinear) as well as "cross" cubemap formats (vertical and horizontal), and row/column cubemap formats, and can produce a mipmapped IBL(Image Based Lighting) or a blurry skybox or both.

Usage

$ cmgen [options] <input-file>
$ cmgen [options] <uv[N]>

Supported input formats

• PNG, 8 and 16 bits
• Radiance (.hdr)
• Photoshop (.psd), 16 and 32 bits
• OpenEXR (.exr)

Options

• --license
  Print copyright and license information
• --quiet, -q
  Quiet mode. Suppress all non-error output
• --type=[cubemap|equirect|octahedron|ktx], -t [cubemap|equirect|octahedron|ktx]
  Specify output type (default: cubemap)
• --format=[exr|hdr|psd|rgbm|rgb32f|png|dds|ktx], -f [exr|hdr|psd|rgbm|rgb32f|png|dds|ktx]
  Specify output file format. ktx implies -type=ktx.
  KTX files are always encoded with 3-channel RGB_10_11_11_REV data
• --compression=COMPRESSION, -c COMPRESSION
  Format specific compression:
  KTX:
  astc_[fast|thorough]_[ldr|hdr]_WxH, where WxH is a valid block size
  s3tc_rgba_dxt5
  etc_FORMAT_METRIC_EFFORT
  FORMAT is rgb8_alpha, srgb8_alpha, rgba8, or srgb8_alpha8
  METRIC is rgba, rgbx, rec709, numeric, or normalxyz
  EFFORT is an integer between 0 and 100
  PNG: Ignored
  PNG RGBM: Ignored
  Radiance: Ignored
  Photoshop: 16 (default), 32
  OpenEXR: RAW, RLE, ZIPS, ZIP, PIZ (default)
  DDS: 8, 16 (default), 32
• --size=power-of-two, -s power-of-two
  Size of the output cubemaps (base level), 256 by default
  Also aplies to DFG LUT
• --deploy=dir, -x dir
  Generate everything needed for deployment into
• --extract=dir
  Extract faces of the cubemap into
• --extract-blur=roughness
  Blurs the cubemap before saving the faces using the roughness blur
• --clamp
  Clamp environment before processing
• --no-mirror
  Skip mirroring of generated cubemaps (for assets with mirroring already backed in)
• --ibl-samples=numSamples
  Number of samples to use for IBL integrations (default 1024)
• --ibl-ld=dir
  Roughness pre-filter into
• --sh-shader
  Generate irradiance SH for shader code

Private use only:

• --ibl-dfg=filename.[exr|hdr|psd|png|rgbm|rgb32f|dds|h|hpp|c|cpp|inc|txt]
  Compute the IBL DFG LUT
• --ibl-dfg-multiscatter
  If --ibl-dfg is set, computes the DFG for multi-scattering GGX
• --ibl-dfg-cloth
  If --ibl-dfg is set, adds a 3rd channel to the DFG for cloth shading
• --ibl-is-mipmap=dir
  Generate mipmap for pre-filtered importance sampling
• --ibl-irradiance=dir
  Diffuse irradiance into
• --ibl-no-prefilter
  Use importance sampling instead of prefiltered importance sampling
• --ibl-min-lod-size
  Minimum LOD size [default: 16]
• --sh=bands
  SH decomposition of input cubemap
• --sh-output=filename.[exr|hdr|psd|rgbm|rgb32f|png|dds|txt]
  SH output format. The filename extension determines the output format
• --sh-irradiance, -i
  Irradiance SH coefficients
• --sh-window=cutoff|no|auto (default), -w cutoff|no|auto (default)
  SH windowing to reduce ringing
• --debug, -d
  Generate extra data for debugging