CRF File

What are CRF files and how to open them

Are you having problems opening a CRF file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your CRF files.

What is a CRF file?

CRF files have multiple uses, and Cal3D Material is one of them. Read more about the other uses further down the page.

Cal3D Material File

Cal3D Material File holds the material properties for a 3D model used with the Cal3D character animation library. It defines how surfaces appear under lighting by specifying ambient, diffuse, and specular colors, as well as shininess. It also lists texture maps by name so rendering engines know which images to apply to the model's surfaces.

This material file is produced by tools exporting Cal3D-format models - such as exporters from modeling packages like 3ds Max - during the final stage of preparing a character. Once created, material files are read by the Cal3D engine alongside mesh, skeleton, and animation files to determine how each part of the mesh should be shaded and what textures to display.

Binary files begin with a magic token consisting of the ASCII characters "CRF" followed by a zero byte. After a 4-byte version number (for example version 700 or 1200), color values for ambient, diffuse, and specular light are stored as four separate 1-byte components each (red, green, blue, alpha). A 4-byte float follows for shininess. Then comes a 4-byte integer indicating how many texture maps are listed, followed by repeated entries where each texture's name is stored as a length-prefixed string.

How to open CRF files

Important: Different programs may use files with the CRF file extension for different purposes, so unless you are sure which format your CRF file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested ten different CRF openers which you will find listed below.

Last updated: September 18, 2026

All known file formats using extension .CRF

While Cal3D Material File is a popular type of CRF-file, we know of 3 different uses of the .CRF file extension. Different software may use files with the same extension for different types of data.

Calcomp Raster Bitmap

Calcomp Raster Bitmap format stores image data intended for use with Calcomp's raster-capable plotters and printers, such as thermal-transfer, electrostatic, and ink-jet plotters. Calcomp devices generate these files to tell the printer exactly how to render each pixel, often including compression to reduce file size and transmission time. Black and white images or simple color modes like 1-bit CMYK are supported; the format's flexibility allows for line printers or large-format devices.

Files using this format are written by Calcomp output filters or drivers when raster output is required rather than vector plot instructions. Software that controls Calcomp plotters (often as part of CAD or large-format printing workflows) produces these files so that the plotter hardware can interpret them directly. After creation, files may be transmitted to the plotter for printing or archived.

The format supports several variations of rasterization and compression depending on device type. In non-compressed ("thermal transfer") mode data may be raw; compressed options include white-space suppression or run-length encoding. Electrostatic plotter modes allow 8-bit bytes with varying compression-unit sizes (8, 16, or 32-bit). Inkjet-interleaved versions exist using similar units or ZIP‐based compression.

Files of this format begin with the two-byte signature 0x02 0x50 (ASCII ".P") at offset 0, which helps software detect them.

Cryo Interactive Font

We know that one CRF format is Cryo Interactive Font. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Various apps that use files with this extension

These apps are known to open certain types of CRF files. Remember, different programs may use CRF files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about CRF file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.