1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
use crate::{Indices, Mesh, MeshBuilder, Meshable, PrimitiveTopology};
use bevy_asset::RenderAssetUsages;
use bevy_math::{primitives::Plane3d, Dir3, Quat, Vec2, Vec3};
use bevy_reflect::prelude::*;
/// A builder used for creating a [`Mesh`] with a [`Plane3d`] shape.
#[derive(Clone, Copy, Debug, Default, Reflect)]
#[reflect(Default, Debug, Clone)]
pub struct PlaneMeshBuilder {
/// The [`Plane3d`] shape.
pub plane: Plane3d,
/// The number of subdivisions along the X axis.
///
/// 0 - is the original plane geometry, the 4 points in the XZ plane.
///
/// 1 - adds a vertex in the middle of the X axis, resulting in a plane with 2 quads / 4 triangles, and a new edge along the Z axis.
///
/// 2 - adds 2 vertices along the X axis, resulting in a plane with 3 quads / 6 triangles.
///
/// and so on...
pub subdivisions_x: u32,
/// The number of subdivisions along the Z axis.
///
/// 0 - is the original plane geometry, the 4 points in the XZ plane.
///
/// 1 - adds a vertex in the middle of the Z axis, resulting in a plane with 2 quads / 4 triangles, and a new edge along the X axis.
///
/// 2 - adds 2 vertices along the Z axis, resulting in a plane with 3 quads / 6 triangles.
///
/// and so on...
pub subdivisions_z: u32,
}
impl PlaneMeshBuilder {
/// Creates a new [`PlaneMeshBuilder`] from a given normal and size.
#[inline]
pub fn new(normal: Dir3, size: Vec2) -> Self {
Self {
plane: Plane3d {
normal,
half_size: size / 2.0,
},
subdivisions_x: 0,
subdivisions_z: 0,
}
}
/// Creates a new [`PlaneMeshBuilder`] from the given size, with the normal pointing upwards.
#[inline]
pub fn from_size(size: Vec2) -> Self {
Self {
plane: Plane3d {
half_size: size / 2.0,
..Default::default()
},
subdivisions_x: 0,
subdivisions_z: 0,
}
}
/// Creates a new [`PlaneMeshBuilder`] from the given length, with the normal pointing upwards,
/// and the resulting [`PlaneMeshBuilder`] being a square.
#[inline]
pub fn from_length(length: f32) -> Self {
Self {
plane: Plane3d {
half_size: Vec2::splat(length) / 2.0,
..Default::default()
},
subdivisions_x: 0,
subdivisions_z: 0,
}
}
/// Sets the normal of the plane, aka the direction the plane is facing.
#[inline]
#[doc(alias = "facing")]
pub fn normal(mut self, normal: Dir3) -> Self {
self.plane = Plane3d {
normal,
..self.plane
};
self
}
/// Sets the size of the plane mesh.
#[inline]
pub fn size(mut self, width: f32, height: f32) -> Self {
self.plane.half_size = Vec2::new(width, height) / 2.0;
self
}
/// Sets the subdivisions of the plane mesh.
///
/// 0 - is the original plane geometry, the 4 points in the XZ plane.
///
/// 1 - is split by 1 line in the middle of the plane on both the X axis and the Z axis,
/// resulting in a plane with 4 quads / 8 triangles.
///
/// 2 - is a plane split by 2 lines on both the X and Z axes, subdividing the plane into 3
/// equal sections along each axis, resulting in a plane with 9 quads / 18 triangles.
#[inline]
pub fn subdivisions(mut self, subdivisions: u32) -> Self {
self.subdivisions_x = subdivisions;
self.subdivisions_z = subdivisions;
self
}
#[inline]
/// The number of subdivisions along the X axis.
///
/// 0 - is the original plane geometry, the 4 points in the XZ plane.
///
/// 1 - adds a vertex in the middle of the X axis, resulting in a plane with 2 quads / 4 triangles, and a new edge along the Z axis.
///
/// 2 - adds 2 vertices along the X axis, resulting in a plane with 3 quads / 6 triangles.
///
/// and so on...
pub fn subdivisions_x(mut self, subdivisions: u32) -> Self {
self.subdivisions_x = subdivisions;
self
}
#[inline]
/// The number of subdivisions along the Z axis.
///
/// 0 - is the original plane geometry, the 4 points in the XZ plane.
///
/// 1 - adds a vertex in the middle of the Z axis, resulting in a plane with 2 quads / 4 triangles, and a new edge along the X axis.
///
/// 2 - adds 2 vertices along the Z axis, resulting in a plane with 3 quads / 6 triangles.
///
/// and so on...
pub fn subdivisions_z(mut self, subdivisions: u32) -> Self {
self.subdivisions_z = subdivisions;
self
}
}
impl MeshBuilder for PlaneMeshBuilder {
fn build(&self) -> Mesh {
let z_vertex_count = self.subdivisions_z + 2;
let x_vertex_count = self.subdivisions_x + 2;
let num_vertices = (z_vertex_count * x_vertex_count) as usize;
let num_indices = ((z_vertex_count - 1) * (x_vertex_count - 1) * 6) as usize;
let mut positions: Vec<Vec3> = Vec::with_capacity(num_vertices);
let mut normals: Vec<[f32; 3]> = Vec::with_capacity(num_vertices);
let mut uvs: Vec<[f32; 2]> = Vec::with_capacity(num_vertices);
let mut indices: Vec<u32> = Vec::with_capacity(num_indices);
let rotation = Quat::from_rotation_arc(Vec3::Y, *self.plane.normal);
let size = self.plane.half_size * 2.0;
for z in 0..z_vertex_count {
for x in 0..x_vertex_count {
let tx = x as f32 / (x_vertex_count - 1) as f32;
let tz = z as f32 / (z_vertex_count - 1) as f32;
let pos = rotation * Vec3::new((-0.5 + tx) * size.x, 0.0, (-0.5 + tz) * size.y);
positions.push(pos);
normals.push(self.plane.normal.to_array());
uvs.push([tx, tz]);
}
}
for z in 0..z_vertex_count - 1 {
for x in 0..x_vertex_count - 1 {
let quad = z * x_vertex_count + x;
indices.push(quad + x_vertex_count + 1);
indices.push(quad + 1);
indices.push(quad + x_vertex_count);
indices.push(quad);
indices.push(quad + x_vertex_count);
indices.push(quad + 1);
}
}
Mesh::new(
PrimitiveTopology::TriangleList,
RenderAssetUsages::default(),
)
.with_inserted_indices(Indices::U32(indices))
.with_inserted_attribute(Mesh::ATTRIBUTE_POSITION, positions)
.with_inserted_attribute(Mesh::ATTRIBUTE_NORMAL, normals)
.with_inserted_attribute(Mesh::ATTRIBUTE_UV_0, uvs)
}
}
impl Meshable for Plane3d {
type Output = PlaneMeshBuilder;
fn mesh(&self) -> Self::Output {
PlaneMeshBuilder {
plane: *self,
subdivisions_x: 0,
subdivisions_z: 0,
}
}
}
impl From<Plane3d> for Mesh {
fn from(plane: Plane3d) -> Self {
plane.mesh().build()
}
}