ALTA  alpha
A BRDF analysis library
ALTA is currently in an alpha stage.


ALTA is a cross-platform software library to analyze, fit and understand BRDFs. It provides a set of command line softwares to fit measured data to analytical forms, tools to understand models and data. You can find an overview presentation of ALTA here.

Target audience

You are working on BRDFs and you want to benchmark new BRDF models and would like to compare them with state-of-the-art BRDF models and data easily. You are working on optical measurements and you want to experiment different fitting procedures and models, or just perform statistical analysis on your data.

Main Features

The full list of features is available in the features page.


ALTA is free software available under the Mozilla Public License, version 2.0. The latest release, version 0.2, can be obtained from the Git repository:

$ git clone
$ git checkout v0.2

See the installation instruction for more information.

The master branch is where new developments take place. We highly recommend using the above release instead of master.

Getting Started

Examples of use can be found in the tutorials section. Also, for a more advance usage of ALTA, please refer to the APIs and references page.

Sample results

Here are results one can obtain using ALTA for nonlinear fitting, rational fitting and data conversion of BRDF data (please click on the picture to change the position of the vertical cut). To see how those results where generated, follow the link above the picture.

Non-linear fitting Rational fitting Data conversion
blue-metallic-paint gold-metallic-paint red-fabric

Those images have been produced using Mitsuba renderer and the ALTA plugin designed for it. Check its GitHub page for more information on how to integrate Mitsuba and ALTA. The scene and environment map were created by Jonas Pilo and Bernhard Vogl respectively.

Citing ALTA

If you are a happy user of ALTA and use it in one of your publication, you are more than welcomed to cite us! You can safely use our EGSR MAM presentation reference or the following software citation:

  title = {{ALTA: A BRDF Analysis Library}},
  author = {Belcour, Laurent and Courtes, Ludovic and Pacanowski, Romain and others},
  year = {2013-2015},
  howpublished = {}

ALTA started with the ANR 11-BS02-006, a research project on light transport analysis.

Inria CNRS UdeM