### 7 releases (4 breaking)

✓ Uses Rust 2018 edition

0.5.0 | Feb 29, 2020 |
---|---|

0.4.0 | Mar 14, 2019 |

0.3.0 | Feb 27, 2019 |

0.2.0 | Feb 25, 2019 |

0.1.2 | Jan 16, 2019 |

#**89** in Data structures

**72** downloads per month

Used in three-d

**MIT**license

230KB

4.5K
SLoC

# tri-mesh

A triangle mesh data structure including basic operations. Use it to create, edit and compute on 3D models.

## Examples

- Morph tool (and source code)
- Stitch tool (and source code)

## Features

- The main struct Mesh implements the half-edge mesh data structure for easy and efficient traversal
- Half-edge walker to traverse the mesh
- Iterators over primitives (vertices, half-edges, edges, faces)
- Measures on vertices, edges and faces (e.g. position of vertex, area of face)
- Edit functionality (e.g. split edge, collapse edge, flip edge)
- Quality functionality (e.g. flip edges recursively to improve triangle quality, collapse small faces)
- Transformations affecting the vertex positions (e.g. moving a single vertex or rotate the entire mesh)
- Intersection functionality (e.g. face/ray intersection, edge/point intersection)
- Merge used for merging of entire meshes (e.g. append one mesh to another or merge overlapping primitives in a mesh)
- Split functionality (e.g. clone a subset of a mesh or split two meshes at their intersection)
- And more...

Please, see the documentation for more details.

## Usage

Add the following to your

:`Cargo .toml`

`[``dependencies``]`
`tri-mesh ``=` `"`0.5.0`"`

### I have a mesh without normals, how can I use `tri-mesh`

to compute them?

`tri-mesh`

`use` `tri_mesh``::``prelude``::``*``;`
`fn` `main``(``)`` ``{`
`//` Construct a mesh from indices and positions buffers.
`let` indices`:` `Vec``<``u32``>` `=` `vec!``[``0``,` `1``,` `2``,` `0``,` `2``,` `3``,` `0``,` `3``,` `1``]``;`
`let` positions`:` `Vec``<``f32``>` `=` `vec!``[``0.``0``,` `0.``0``,` `0.``0``,` `1.``0``,` `0.``0``,` `-``0.``5``,` `-``1.``0``,` `0.``0``,` `-``0.``5``,` `0.``0``,` `0.``0``,` `1.``0``]``;`
`let` mesh `=` `MeshBuilder``::`new`(``)``.``with_indices``(`indices`)``.``with_positions``(`positions`)``.``build``(``)``.``unwrap``(``)``;`
`//` Get the indices, positions and normal buffers
`let` indices_out `=` mesh`.``indices_buffer``(``)``;`
`let` positions_out `=` mesh`.``positions_buffer``(``)``;`
`let` normals_out `=` mesh`.``normals_buffer``(``)``;`
`}`

### I need the bounding box of my mesh, how can I get that?

`use` `tri_mesh``::``prelude``::``*``;`
`fn` `main``(``)`` ``{`
`//` Construct any mesh, this time, we will construct a simple icosahedron
`let` mesh `=` `MeshBuilder``::`new`(``)``.``icosahedron``(``)``.``build``(``)``.``unwrap``(``)``;`
`//` Compute the extreme coordinates which defines the axis aligned bounding box..
`let` `(`min_coordinates`,` max_coordinates`)` `=` mesh`.``extreme_coordinates``(``)``;`
`//` .. or construct an actual mesh representing the axis aligned bounding box
`let` aabb `=` mesh`.``axis_aligned_bounding_box``(``)``;`
`//` Export the bounding box to an obj file
`std``::``fs``::`write`(``"`foo.obj`"``,` mesh`.``parse_as_obj``(``)``)``.``unwrap``(``)``;`
`}`

### I want to stitch two meshes together, how do I do that?

`use` `tri_mesh``::``prelude``::``*``;`
`fn` `main``(``)`` ``{`
`//` Construct two meshes
`let` `mut` mesh1 `=` `MeshBuilder``::`new`(``)``.``cube``(``)``.``build``(``)``.``unwrap``(``)``;`
`let` `mut` mesh2 `=` `MeshBuilder``::`new`(``)``.``cube``(``)``.``build``(``)``.``unwrap``(``)``;`
mesh2`.``translate``(``vec3``(``0.``5``,` `0.``5``,` `0.``5``)``)``;`
`//` Split the two meshes at their intersection creating two sets of sub meshes
`let` `(``mut` meshes1`,` `mut` meshes2`)` `=` mesh1`.``split_at_intersection``(``&``mut` mesh2`)``;`
`//` Choose two sub meshes to merge (here we just choose one sub mesh from each of the original meshes)
`let` `mut` result `=` meshes1`.``first``(``)``.``unwrap``(``)``.``clone``(``)``;`
result`.``merge_with``(`meshes2`.``first``(``)``.``unwrap``(``)``)``.``unwrap``(``)``;`
`}`

### How can I use `tri-mesh`

to compute my own very special curvature measure?

`tri-mesh`

`use` `tri_mesh``::``prelude``::``*``;`
`fn` `main``(``)`` ``{`
`//` Construct any mesh, for simplicity, let's use a cube mesh
`let` mesh `=` `MeshBuilder``::`new`(``)``.``cube``(``)``.``build``(``)``.``unwrap``(``)``;`
`let` `mut` curvature_measure `=` `0.``0``;`
`//` Let's say that the curvature measure is a sum of a curvature measure for each vertex
`//` which means we need to visit all vertices
`for` vertex_id `in` mesh`.``vertex_iter``(``)`
`{`
`//` Let's say that to compute the curvature of one vertex we need to visit the neighbouring faces
`//` We will do that by iterating the half-edges pointing away from the vertex ..
`let` `mut` curvature_measure_vertex `=` `0.``0``;`
`for` halfedge_id `in` mesh`.``vertex_halfedge_iter``(`vertex_id`)` `{`
`//` .. and then create a walker from that halfedge and then get the face pointed to by that walker
`if` `let` `Some``(`face_id`)` `=` mesh`.``walker_from_halfedge``(`halfedge_id`)``.``face_id``(``)` `{`
`//` Finally, insert the code for computing your special vertex curvature measure right here!
`//` curvature_measure_vertex += ??;
`}`
`}`
curvature_measure `+=` curvature_measure_vertex`;`
`}`
`}`

#### Dependencies

~0.8–1MB

~21K SLoC