Mesh builder and line support generation

mslicer/src/windows/supports.rs

@@ -1,7 +1,7 @@
 use egui::{Context, Ui};
 use slicer::supports::line::LineSupportGenerator;
 
-use crate::{app::App, ui::components::dragger};
+use crate::{app::App, render::rendered_mesh::RenderedMesh, ui::components::dragger};
 
 pub fn ui(app: &mut App, ui: &mut Ui, _ctx: &Context) {
     if ui.button("Generate").clicked() {
@@ -11,9 +11,17 @@ pub fn ui(app: &mut App, ui: &mut Ui, _ctx: &Context) {
             app.slice_config.platform_size,
         );
 
-        for mesh in app.meshes.read().iter() {
+        let mut meshes = app.meshes.write();
+
+        for i in 0..meshes.len() {
+            let mesh = &meshes[i];
+
             let supports = generator.generate_line_supports(&mesh.mesh);
-            app.state.line_support_debug.extend(supports);
+            let mesh = RenderedMesh::from_mesh(supports)
+                .with_name("Supports".into())
+                .with_random_color();
+
+            meshes.push(mesh);
         }
     }
 

slicer/src/builder.rs

@@ -0,0 +1,108 @@
+use std::f32::consts::PI;
+
+use anyhow::Result;
+use nalgebra::Vector3;
+use stl_io::Triangle;
+
+use crate::mesh::Mesh;
+
+pub struct MeshBuilder {
+    vertices: Vec<Vector3<f32>>,
+    normals: Vec<Vector3<f32>>,
+    faces: Vec<[u32; 3]>,
+}
+
+impl MeshBuilder {
+    pub fn new() -> Self {
+        Self {
+            vertices: Vec::new(),
+            normals: Vec::new(),
+            faces: Vec::new(),
+        }
+    }
+
+    pub fn add_vertex(&mut self, vertex: Vector3<f32>) -> u32 {
+        self.vertices.push(vertex);
+        (self.vertices.len() - 1) as u32
+    }
+
+    pub fn add_face(&mut self, face: [u32; 3], normal: Vector3<f32>) {
+        self.faces.push(face);
+        self.normals.push(normal);
+    }
+
+    pub fn add_quad(&mut self, quad: [u32; 4], normal: Vector3<f32>) {
+        self.add_face([quad[0], quad[1], quad[2]], normal);
+        self.add_face([quad[1], quad[2], quad[3]], normal);
+    }
+
+    pub fn build(self) -> Mesh {
+        Mesh::new(self.vertices, self.faces, self.normals)
+    }
+
+    pub fn save_stl(&self, path: &str) -> Result<()> {
+        let mut stl = Vec::new();
+
+        for (face, normal) in self.faces.iter().zip(self.normals.iter()) {
+            let (a, b, c) = (
+                self.vertices[face[0] as usize],
+                self.vertices[face[1] as usize],
+                self.vertices[face[2] as usize],
+            );
+
+            let into_stl = |v: Vector3<f32>| stl_io::Vertex::new([v.x, v.y, v.z]);
+            stl.push(Triangle {
+                normal: into_stl(*normal),
+                vertices: [into_stl(a), into_stl(b), into_stl(c)],
+            });
+        }
+
+        let mut file = std::fs::File::create(path)?;
+        stl_io::write_stl(&mut file, stl.iter())?;
+        Ok(())
+    }
+}
+
+impl MeshBuilder {
+    pub fn add_vertical_cylinder(
+        &mut self,
+        bottom: Vector3<f32>,
+        height: f32,
+        radius: f32,
+        precision: u32,
+    ) {
+        let top = bottom + Vector3::new(0.0, 0.0, height);
+        let bottom_center = self.add_vertex(bottom);
+        let top_center = self.add_vertex(top);
+
+        let mut last = None;
+        let mut fist = None;
+        for i in 0..precision {
+            let angle = 2.0 * PI * (i as f32) / (precision as f32);
+            let normal = Vector3::new(angle.cos(), angle.sin(), 0.0);
+            let offset = normal * radius;
+
+            let top = self.add_vertex(top + offset);
+            let bottom = self.add_vertex(bottom + offset);
+
+            if let Some((last_top, last_bottom)) = last {
+                self.add_quad([last_top, last_bottom, top, bottom], normal);
+                self.add_face([last_top, top, top_center], Vector3::z());
+                self.add_face([last_bottom, bottom_center, bottom], -Vector3::z());
+            }
+
+            last = Some((top, bottom));
+            if fist.is_none() {
+                fist = Some((top, bottom, normal));
+            }
+        }
+
+        if let Some((first_top, first_bottom, normal)) = fist {
+            if let Some((last_top, last_bottom)) = last {
+                self.add_quad([last_top, last_bottom, first_top, first_bottom], normal);
+                self.add_face([last_top, first_top, top_center], Vector3::z());
+                self.add_face([last_bottom, bottom_center, first_bottom], -Vector3::z());
+            }
+        }
+    }
+}

slicer/src/lib.rs

@@ -2,6 +2,7 @@
 
 use nalgebra::Vector3;
 
+pub mod builder;
 pub mod half_edge;
 pub mod mesh;
 pub mod segments;

slicer/src/mesh.rs

@@ -35,7 +35,13 @@ impl Mesh {
     /// transformations are all 0 by default.
     pub fn new(mut vertices: Vec<Pos>, faces: Vec<[u32; 3]>, normals: Vec<Pos>) -> Self {
         center_vertices(&mut vertices);
+        Self::new_uncentred(vertices, faces, normals)
+    }
 
+    /// Creates a new mesh from the givin vertices and faces. The
+    /// transformations are all 0 by default and the vertices are
+    /// not centered.
+    pub fn new_uncentred(vertices: Vec<Pos>, faces: Vec<[u32; 3]>, normals: Vec<Pos>) -> Self {
         Self {
             inner: Arc::new(MeshInner {
                 vertices: vertices.into_boxed_slice(),

slicer/src/supports/line.rs

@@ -4,7 +4,7 @@ use nalgebra::{Vector2, Vector3};
 use ordered_float::OrderedFloat;
 use tracing::info;
 
-use crate::{half_edge::HalfEdgeMesh, mesh::Mesh};
+use crate::{builder::MeshBuilder, half_edge::HalfEdgeMesh, mesh::Mesh};
 
 pub struct LineSupportGenerator<'a> {
     config: &'a LineSupportConfig,
@@ -18,6 +18,11 @@ pub struct LineSupport {
 }
 
 pub struct LineSupportConfig {
+    /// Support generation
+    pub support_radius: f32,
+    pub base_radius: f32,
+
+    /// Overhang detection
     pub max_origin_normal_z: f32,
     pub max_neighbor_z_diff: f32,
     pub min_angle: f32,
@@ -29,16 +34,33 @@ impl<'a> LineSupportGenerator<'a> {
         Self { config, bed_size }
     }
 
-    pub fn generate_line_supports(&self, mesh: &Mesh) -> Vec<[Vector3<f32>; 2]> {
+    pub fn generate_line_supports(&self, mesh: &Mesh) -> Mesh {
         let half_edge_mesh = HalfEdgeMesh::new(mesh);
 
-        let mut points = Vec::new();
+        let mut overhangs = Vec::new();
-        points.extend_from_slice(&self.detect_point_overhangs(mesh, &half_edge_mesh));
-        points.extend_from_slice(&self.detect_face_overhangs(mesh));
 
-        info!("Line support generation identified {} points", points.len());
+        let point_overhangs = self.detect_point_overhangs(mesh, &half_edge_mesh);
+        overhangs.extend_from_slice(&point_overhangs);
 
-        points
+        let face_overhangs = self.detect_face_overhangs(mesh);
+        overhangs.extend_from_slice(&face_overhangs);
+
+        info!(
+            "Found {} overhangs {{ face: {}, point: {} }}",
+            overhangs.len(),
+            face_overhangs.len(),
+            point_overhangs.len()
+        );
+
+        let mut out = MeshBuilder::new();
+        for [origin, _normal] in overhangs {
+            let bottom = origin.xy().to_homogeneous();
+            out.add_vertical_cylinder(bottom, origin.z, self.config.support_radius, 10);
+        }
+
+        out.save_stl("debug.stl").unwrap();
+
+        out.build()
     }
 
     /// Find all points that are both lower than their surrounding points and have down facing normals
@@ -183,6 +205,9 @@ fn ray_triangle_intersection(
 impl Default for LineSupportConfig {
     fn default() -> Self {
         Self {
+            support_radius: 0.1,
+            base_radius: 1.0,
+
             max_origin_normal_z: 0.0,
             max_neighbor_z_diff: -0.01,
             min_angle: 3.0,