https://github.com/mrdimas/lightmap
Light maps generator
https://github.com/mrdimas/lightmap
Last synced: 7 months ago
JSON representation
Light maps generator
- Host: GitHub
- URL: https://github.com/mrdimas/lightmap
- Owner: mrDIMAS
- License: mit
- Created: 2024-03-06T15:26:38.000Z (over 1 year ago)
- Default Branch: master
- Last Pushed: 2024-10-21T18:16:54.000Z (about 1 year ago)
- Last Synced: 2025-03-25T15:33:13.381Z (7 months ago)
- Language: Rust
- Size: 21.5 KB
- Stars: 4
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# lightmap
Light maps generator.
## Example
```rust
use lightmap::{
input::{Mesh, WorldVertex},
light::{LightDefinition, PointLightDefinition},
LightMap,
};
use nalgebra::{Vector2, Vector3};
#[derive(Copy, Clone, Debug, Default, PartialEq)]
pub struct Vertex {
pub position: Vector3,
pub tex_coord: Vector2,
}
impl Vertex {
fn new(x: f32, y: f32, z: f32) -> Self {
Self {
position: Vector3::new(x, y, z),
tex_coord: Default::default(),
}
}
}
// Create cube geometry.
let mut vertices = vec![
Vertex::new(-0.5, -0.5, 0.5),
Vertex::new(-0.5, 0.5, 0.5),
Vertex::new(0.5, 0.5, 0.5),
Vertex::new(0.5, -0.5, 0.5),
Vertex::new(-0.5, -0.5, -0.5),
Vertex::new(-0.5, 0.5, -0.5),
Vertex::new(0.5, 0.5, -0.5),
Vertex::new(0.5, -0.5, -0.5),
];
let mut triangles = vec![
// Front
[2, 1, 0],
[3, 2, 0],
// Back
[4, 5, 6],
[4, 6, 7],
// Right
[7, 6, 2],
[2, 3, 7],
// Left
[0, 1, 5],
[0, 5, 4],
// Top
[5, 1, 2],
[5, 2, 6],
// Bottom
[3, 0, 4],
[7, 3, 4],
];
// Step 1. Generate second texture coordinates first.
let patch = uvgen::generate_uvs(
vertices.iter().map(|v| v.position),
triangles.iter().cloned(),
0.005,
)
.unwrap();
// Step 2. Clone vertices on seams.
for &vertex_index in &patch.additional_vertices {
let vertex = vertices[vertex_index as usize];
vertices.push(vertex);
}
// Step 3. Assign generated second texture coordinates.
for (vertex, tex_coord) in vertices.iter_mut().zip(&patch.second_tex_coords) {
vertex.tex_coord = *tex_coord;
}
// Step 4. Replace topology of the mesh using new one, that was produced when generating UVs.
triangles = patch.triangles;
// Step 5. Generate light map.
let lights = [LightDefinition::Point(PointLightDefinition {
intensity: 1.0,
color: Vector3::new(1.0, 1.0, 1.0),
radius: 2.0,
position: Vector3::new(0.0, 2.0, 0.0),
sqr_radius: 4.0,
})];
let mut mesh = Mesh::new(
vertices
.iter()
.map(|v| WorldVertex {
world_normal: Default::default(),
world_position: v.position,
second_tex_coord: v.tex_coord,
})
.collect(),
triangles,
)
.unwrap();
// Calculate normals.
for triangle in mesh.triangles.iter() {
let pos_a = mesh.vertices[triangle[0] as usize].world_position;
let pos_b = mesh.vertices[triangle[1] as usize].world_position;
let pos_c = mesh.vertices[triangle[2] as usize].world_position;
let normal = (pos_c - pos_a)
.cross(&(pos_c - pos_b))
.try_normalize(f32::EPSILON)
.unwrap_or_default();
mesh.vertices[triangle[0] as usize].world_normal = normal;
mesh.vertices[triangle[1] as usize].world_normal = normal;
mesh.vertices[triangle[2] as usize].world_normal = normal;
}
let meshes = vec![mesh];
let light_map = LightMap::new(&meshes[0], &meshes, &lights, 64);
dbg!(light_map);
```