---
name: "cgalsurf"
section: "7"
platform: "linux"
package: "iso2mesh-tools"
version: "1.9.8+ds-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/cgalsurf"
---

# cgalsurf(7)

3D surface mesh extraction from volumetric image

## NAME

cgalsurf - 3D surface mesh extraction from volumetric image

## SYNOPSIS

cgalsurf input.inr threshold x0 y0 z0 r2 angle surf-size approx maxnode output.off \<randomseed\> \<init-size\>

## DESCRIPTION

The cgalsurf utility extracts a surface mesh at a specified threshold (level-set) from a volumetric image - either in binary or gray-scale  values, using the CGAL library (http://cgal.org). This utility is adapted based on the 3D surface generation demo in the CGAL package.

Please see https://doc.cgal.org/latest/Surface\_mesher/ for details regarding the underlying algorithm.

## OPTIONS

This program accepts the following input parameters (all but the last two  parameters are required):

- **input.inr**

  **The input volumetric image in the INR format**

- **threshold**

  **A number representing the threshold at which the surface is extracted.**

- **x0**

  **The bounding sphere center x-coordinate**

- **y0**

  **The bounding sphere center y-coordinate**

- **z0**

  **The bounding sphere center y-coordinate**

- **r2**

  **The bounding sphere's radius squared**

- **angle**

  **Lower-bound of the angles (in degree) in surface triangles**

- **surf-size**

  **Lower-bound of the edge-length (in voxel unit) in surface triangles**

- **approx**

  **Upper-bound of the deviation distance (in voxel unit) of the surface triangles to the voxelated boundaries**

- **maxnode**

  **Upper-bound of the node numbers in the output mesh**

- **output.off**

  **Output surface mesh in the OFF format**

- **randomseed**\|(optional, default: -1)

  Random number generator seed (large positive integer, -1 to use system clock)

- **init-size**\|(optional)

  The number of nodes in the initial surface (sampled on the bounding sphere) [cgalmesh(7)](/cgalmesh/7.md), [cgalsimp2(7)](/cgalsimp2/7.md), [cgalpoly(7)](/cgalpoly/7.md), cork(7), [meshfix(7)](/meshfix/7.md), [jmeshlib(7)](/jmeshlib/7.md)

## AUTHOR

Laurent Rineau, Mariette Yvinec, and Qianqian Fang (fangqq@gmail.com)