---
name: "roughness-prefilter"
section: "1"
platform: "linux"
package: "libfilament-tools"
version: "1.9.25+dfsg3-1+b2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/roughness-prefilter"
---

# roughness-prefilter(1)

filament material tools

## NAME

roughness-prefilter - filament material tools

## DESCRIPTION

roughness-prefilter generates pre-filtered roughness maps from normal maps to help mitigate specular aliasing. Usage:

-

  roughness-prefilter \[options\] \<normal-map\> \<output-roughness-map\>

### Output note:

-

  One file will be generated per mip-level. The size of the first level will be the greater of the input normal map and input roughness map.

### Supported input formats:

-

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

## OPTIONS

**--help**, **-h**

-

  print this message

**--license**

-

  Print copyright and license information

**--roughness**=*\[0*..1\], **-r** \[0..1\]

-

  desired constant roughness, ignored if **--roughness-map** is specified

**--roughness-map=**\<input-roughness-map\>, **-m** \<input-roughness-map\>

-

  input roughness map

**--format**=*\[exr*\|hdr\|psd\|png\|dds\|ktx\], **-f** \[exr\|hdr\|psd\|png\|dds\|ktx\]

-

  specify output file format, inferred from file name if omitted

**--compression**=*COMPRESSION*, **-c** COMPRESSION

-

  format specific compression:

-

  PNG: Ignored Radiance: Ignored Photoshop: 16 (default), 32 OpenEXR: RAW, RLE, ZIPS, ZIP, PIZ (default) DDS: 8, 16 (default), 32

**--linear**, **-l**

-

  force linear output when the PNG format is selected

to help mitigate specular aliasing. Usage:

-

  roughness-prefilter \[options\] \<normal-map\> \<output-roughness-map\>

### Output note:

-

  One file will be generated per mip-level. The size of the first level will be the greater of the input normal map and input roughness map.

### Supported input formats:

-

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

**--help**, **-h**

-

  print this message

**--license**

-

  Print copyright and license information

**--roughness**=*\[0*..1\], **-r** \[0..1\]

-

  desired constant roughness, ignored if **--roughness-map** is specified

**--roughness-map=**\<input-roughness-map\>, **-m** \<input-roughness-map\>

-

  input roughness map

**--format**=*\[exr*\|hdr\|psd\|png\|dds\|ktx\], **-f** \[exr\|hdr\|psd\|png\|dds\|ktx\]

-

  specify output file format, inferred from file name if omitted

**--compression**=*COMPRESSION*, **-c** COMPRESSION

-

  format specific compression:

-

  PNG: Ignored Radiance: Ignored Photoshop: 16 (default), 32 OpenEXR: RAW, RLE, ZIPS, ZIP, PIZ (default) DDS: 8, 16 (default), 32

**--linear**, **-l**

-

  force linear output when the PNG format is selected