Image density/height map to mesh generator

About

Crates used to generate 2D mesh from images representing density/height map.

Algorithm gets source image:

Converts it into density/height values (here from alpha channell):

Next makes steepness values:

And builds mesh based on the highest steepness points:

Rust API

Important modules

• https://crates.io/crates/density-mesh-core - Module used to generate mesh from density map.
• https://crates.io/crates/density-mesh-image - Module used to generate density map from image.

Typical use case would be to use two of them to create mesh from images but in case you have your own image handler, you can stick to the core module and produce density maps by yourself.

Working with chunks

In the past, there was a way to optimize work with big maps using chunks - these chunks wasn't giving a reliable topology and had to be removed.

Real-time density mesh modifications

Imagine that you have a one big mesh, you want to modify variable size regions of this mesh and don't want to split it into chunks - for this use case there is specialized DensityMeshGenerator type. Keep in mind that at the moment, even if you change only really smart part of the map, whole mesh will be rebuilt so for big maps this might take long which means, for now you shouldn't use this crate for high performance, HD maps generation.

let image = DynamicImage::ImageRgba8(
    image::open("../resources/heightmap.png")
        .expect("Cannot open file")
        .to_rgba(),
);
let settings = GenerateDensityImageSettings::default();
let map = generate_densitymap_from_image(image.clone(), &settings)
    .expect("Cannot produce density map image");
let settings = GenerateDensityMeshSettings {
    points_separation: 16.0.into(),
    keep_invisible_triangles: true,
    ..Default::default()
};
let mut generator = DensityMeshGenerator::new(vec![], map, settings.clone());
generator.process_wait().expect("Cannot process changes");
generator
    .change_map(64, 64, 128, 128, vec![255; 128 * 128], settings.clone())
    .expect("Cannot change live mesh map region");
generator
    .process_wait()
    .expect("Cannot process live changes");
generator
    .change_map(384, 384, 64, 64, vec![0; 64 * 64], settings)
    .expect("Cannot change live mesh map region");
generator
    .process_wait()
    .expect("Cannot process live changes");
let mut image = DynamicImage::ImageRgba8(
    generate_image_from_densitymap(generator.map(), false).to_rgba(),
);
apply_mesh_on_map(&mut image, generator.mesh().unwrap());
image
    .save("../resources/heightmap.live.png")
    .expect("Cannot save output image");

With that we have added two solid rectangles and result looks like:

Optimizations of map region changes

Previous versions had live mesh generator which regenerated only the parts of the mesh that given region has changed - for now this is not further supported because of corner case situations where mesh generation crashes internally making use of this feature unreliable. This feature wil be added later when it will be redesigned.

CLI

Install / Update

cargo install density-mesh-cli --force

Example

density-mesh mesh -i image.png -o mesh.obj --obj

Options

density-mesh-cli 1.4.0
Patryk 'PsichiX' Budzynski <psichix@gmail.com>
CLI app for density mesh generator

USAGE:
    density-mesh.exe [SUBCOMMAND]

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

SUBCOMMANDS:
    help     Prints this message or the help of the given subcommand(s)
    image    Produce density map image
    mesh     Produce density mesh

density-mesh.exe-image
Produce density map image

USAGE:
    density-mesh.exe image [FLAGS] [OPTIONS] --input <PATH> --output <PATH>

FLAGS:
    -h, --help         Prints help information
    -s, --steepness    Produce steepness image
    -V, --version      Prints version information
        --verbose      Display settings used

OPTIONS:
        --density-source <NAME>    Density source: luma, luma-alpha, red, green, blue, alpha [default: luma-alpha]
    -i, --input <PATH>             Input image file
    -o, --output <PATH>            Output image file
        --scale <INTEGER>          Image scale [default: 1]

density-mesh.exe-mesh
Produce density mesh

USAGE:
    density-mesh.exe mesh [FLAGS] [OPTIONS] --input <PATH> --output <PATH> <--json|--json-pretty|--yaml|--obj|--png>

FLAGS:
    -h, --help                        Prints help information
        --json                        Produce JSON mesh
        --json-pretty                 Produce pretty JSON mesh
        --keep-invisible-triangles    Keep invisible triangles
        --obj                         Produce OBJ mesh
        --png                         Produce PNG mesh visualization
    -V, --version                     Prints version information
        --verbose                     Display settings used
        --yaml                        Produce YAML mesh

OPTIONS:
        --density-source <NAME>            Density source: luma, luma-alpha, red, green, blue, alpha [default: luma-
                                           alpha]
        --extrude-size <NUMBER>            Extrude size
    -i, --input <PATH>                     Input image file
        --max-iterations <INTEGER>         Maximum tries number when finding point to place [default: 32]
    -o, --output <PATH>                    Output mesh file
        --points-separation <NUMBER>       Points separation [default: 10]
        --scale <INTEGER>                  Image scale [default: 1]
        --steepness-threshold <NUMBER>     Steepness threshold [default: 0.01]
        --update-region-margin <NUMBER>    Margin around update region box [default: 0]
        --visibility-threshold <NUMBER>    VIsibility threshold [default: 0.01]