separating finite and infinite 3d planes (#12426)

# Objective

Fixes #12388

## Solution

- Removing the plane3d and adding rect3d primitive mesh

crates/bevy_gizmos/src/primitives/dim3.rs

@@ -134,18 +134,18 @@ impl<T: GizmoConfigGroup> Drop for SphereBuilder<'_, '_, '_, T> {
 
 // plane 3d
 
-/// Builder for configuring the drawing options of [`Sphere`].
+/// Builder for configuring the drawing options of [`Plane3d`].
 pub struct Plane3dBuilder<'a, 'w, 's, T: GizmoConfigGroup> {
     gizmos: &'a mut Gizmos<'w, 's, T>,
 
     // direction of the normal orthogonal to the plane
     normal: Dir3,
 
-    // Rotation of the sphere around the origin in 3D space
+    // Rotation of the plane around the origin in 3D space
     rotation: Quat,
-    // Center position of the sphere in 3D space
+    // Center position of the plane in 3D space
     position: Vec3,
-    // Color of the sphere
+    // Color of the plane
     color: Color,
 
     // Number of axis to hint the plane

crates/bevy_math/src/bounding/bounded3d/primitive_impls.rs

@@ -3,8 +3,8 @@
 use crate::{
     bounding::{Bounded2d, BoundingCircle},
     primitives::{
-        BoxedPolyline3d, Capsule3d, Cone, ConicalFrustum, Cuboid, Cylinder, Line3d, Plane3d,
-        Polyline3d, Segment3d, Sphere, Torus, Triangle2d,
+        BoxedPolyline3d, Capsule3d, Cone, ConicalFrustum, Cuboid, Cylinder, InfinitePlane3d,
+        Line3d, Polyline3d, Segment3d, Sphere, Torus, Triangle2d,
     },
     Dir3, Mat3, Quat, Vec2, Vec3,
 };
@@ -21,7 +21,7 @@ impl Bounded3d for Sphere {
     }
 }
 
-impl Bounded3d for Plane3d {
+impl Bounded3d for InfinitePlane3d {
     fn aabb_3d(&self, translation: Vec3, rotation: Quat) -> Aabb3d {
         let normal = rotation * *self.normal;
         let facing_x = normal == Vec3::X || normal == Vec3::NEG_X;
@@ -310,7 +310,7 @@ mod tests {
     use crate::{
         bounding::Bounded3d,
         primitives::{
-            Capsule3d, Cone, ConicalFrustum, Cuboid, Cylinder, Line3d, Plane3d, Polyline3d,
+            Capsule3d, Cone, ConicalFrustum, Cuboid, Cylinder, InfinitePlane3d, Line3d, Polyline3d,
             Segment3d, Sphere, Torus,
         },
         Dir3,
@@ -334,23 +334,24 @@ mod tests {
     fn plane() {
         let translation = Vec3::new(2.0, 1.0, 0.0);
 
-        let aabb1 = Plane3d::new(Vec3::X).aabb_3d(translation, Quat::IDENTITY);
+        let aabb1 = InfinitePlane3d::new(Vec3::X).aabb_3d(translation, Quat::IDENTITY);
         assert_eq!(aabb1.min, Vec3::new(2.0, -f32::MAX / 2.0, -f32::MAX / 2.0));
         assert_eq!(aabb1.max, Vec3::new(2.0, f32::MAX / 2.0, f32::MAX / 2.0));
 
-        let aabb2 = Plane3d::new(Vec3::Y).aabb_3d(translation, Quat::IDENTITY);
+        let aabb2 = InfinitePlane3d::new(Vec3::Y).aabb_3d(translation, Quat::IDENTITY);
         assert_eq!(aabb2.min, Vec3::new(-f32::MAX / 2.0, 1.0, -f32::MAX / 2.0));
         assert_eq!(aabb2.max, Vec3::new(f32::MAX / 2.0, 1.0, f32::MAX / 2.0));
 
-        let aabb3 = Plane3d::new(Vec3::Z).aabb_3d(translation, Quat::IDENTITY);
+        let aabb3 = InfinitePlane3d::new(Vec3::Z).aabb_3d(translation, Quat::IDENTITY);
         assert_eq!(aabb3.min, Vec3::new(-f32::MAX / 2.0, -f32::MAX / 2.0, 0.0));
         assert_eq!(aabb3.max, Vec3::new(f32::MAX / 2.0, f32::MAX / 2.0, 0.0));
 
-        let aabb4 = Plane3d::new(Vec3::ONE).aabb_3d(translation, Quat::IDENTITY);
+        let aabb4 = InfinitePlane3d::new(Vec3::ONE).aabb_3d(translation, Quat::IDENTITY);
         assert_eq!(aabb4.min, Vec3::splat(-f32::MAX / 2.0));
         assert_eq!(aabb4.max, Vec3::splat(f32::MAX / 2.0));
 
-        let bounding_sphere = Plane3d::new(Vec3::Y).bounding_sphere(translation, Quat::IDENTITY);
+        let bounding_sphere =
+            InfinitePlane3d::new(Vec3::Y).bounding_sphere(translation, Quat::IDENTITY);
         assert_eq!(bounding_sphere.center, translation);
         assert_eq!(bounding_sphere.radius(), f32::MAX / 2.0);
     }

crates/bevy_math/src/primitives/dim3.rs

@@ -3,7 +3,7 @@ use std::f32::consts::{FRAC_PI_3, PI};
 use super::{Circle, Primitive3d};
 use crate::{
     bounding::{Aabb3d, Bounded3d, BoundingSphere},
-    Dir3, InvalidDirectionError, Mat3, Quat, Vec3,
+    Dir3, InvalidDirectionError, Mat3, Quat, Vec2, Vec3,
 };
 
 /// A sphere primitive
@@ -67,33 +67,38 @@ impl Sphere {
     }
 }
 
-/// An unbounded plane in 3D space. It forms a separating surface through the origin,
-/// stretching infinitely far
+/// A bounded plane in 3D space. It forms a surface starting from the origin with a defined height and width.
 #[derive(Clone, Copy, Debug, PartialEq)]
 #[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
 pub struct Plane3d {
     /// The normal of the plane. The plane will be placed perpendicular to this direction
     pub normal: Dir3,
+    /// Half of the width and height of the plane
+    pub half_size: Vec2,
 }
 impl Primitive3d for Plane3d {}
 
 impl Default for Plane3d {
-    /// Returns the default [`Plane3d`] with a normal pointing in the `+Y` direction.
+    /// Returns the default [`Plane3d`] with a normal pointing in the `+Y` direction, width and height of `1.0`.
     fn default() -> Self {
-        Self { normal: Dir3::Y }
+        Self {
+            normal: Dir3::Y,
+            half_size: Vec2::splat(0.5),
+        }
     }
 }
 
 impl Plane3d {
-    /// Create a new `Plane3d` from a normal
+    /// Create a new `Plane3d` from a normal and a half size
     ///
     /// # Panics
     ///
     /// Panics if the given `normal` is zero (or very close to zero), or non-finite.
     #[inline(always)]
-    pub fn new(normal: Vec3) -> Self {
+    pub fn new(normal: Vec3, half_size: Vec2) -> Self {
         Self {
             normal: Dir3::new(normal).expect("normal must be nonzero and finite"),
+            half_size,
         }
     }
 
@@ -109,8 +114,71 @@ impl Plane3d {
     /// are *collinear* and lie on the same line.
     #[inline(always)]
     pub fn from_points(a: Vec3, b: Vec3, c: Vec3) -> (Self, Vec3) {
-        let normal = Dir3::new((b - a).cross(c - a))
-            .expect("plane must be defined by three finite points that don't lie on the same line");
+        let normal = Dir3::new((b - a).cross(c - a)).expect(
+            "finite plane must be defined by three finite points that don't lie on the same line",
+        );
+        let translation = (a + b + c) / 3.0;
+
+        (
+            Self {
+                normal,
+                ..Default::default()
+            },
+            translation,
+        )
+    }
+}
+
+/// An unbounded plane in 3D space. It forms a separating surface through the origin,
+/// stretching infinitely far
+#[derive(Clone, Copy, Debug, PartialEq)]
+#[cfg_attr(feature = "serialize", derive(serde::Serialize, serde::Deserialize))]
+pub struct InfinitePlane3d {
+    /// The normal of the plane. The plane will be placed perpendicular to this direction
+    pub normal: Dir3,
+}
+impl Primitive3d for InfinitePlane3d {}
+
+impl Default for InfinitePlane3d {
+    /// Returns the default [`InfinitePlane3d`] with a normal pointing in the `+Y` direction.
+    fn default() -> Self {
+        Self { normal: Dir3::Y }
+    }
+}
+
+impl InfinitePlane3d {
+    /// Create a new `InfinitePlane3d` from a normal
+    ///
+    /// # Panics
+    ///
+    /// Panics if the given `normal` is zero (or very close to zero), or non-finite.
+    #[inline(always)]
+    pub fn new<T: TryInto<Dir3>>(normal: T) -> Self
+    where
+        <T as TryInto<Dir3>>::Error: std::fmt::Debug,
+    {
+        Self {
+            normal: normal
+                .try_into()
+                .expect("normal must be nonzero and finite"),
+        }
+    }
+
+    /// Create a new `InfinitePlane3d` based on three points and compute the geometric center
+    /// of those points.
+    ///
+    /// The direction of the plane normal is determined by the winding order
+    /// of the triangular shape formed by the points.
+    ///
+    /// # Panics
+    ///
+    /// Panics if a valid normal can not be computed, for example when the points
+    /// are *collinear* and lie on the same line.
+    #[inline(always)]
+    pub fn from_points(a: Vec3, b: Vec3, c: Vec3) -> (Self, Vec3) {
+        let normal = Dir3::new((b - a).cross(c - a)).expect(
+            "infinite plane must be defined by three finite points that don't lie on the same line",
+        );
         let translation = (a + b + c) / 3.0;
 
         (Self { normal }, translation)
@@ -975,6 +1043,14 @@ mod tests {
     fn plane_from_points() {
         let (plane, translation) = Plane3d::from_points(Vec3::X, Vec3::Z, Vec3::NEG_X);
         assert_eq!(*plane.normal, Vec3::NEG_Y, "incorrect normal");
+        assert_eq!(plane.half_size, Vec2::new(0.5, 0.5), "incorrect half size");
+        assert_eq!(translation, Vec3::Z * 0.33333334, "incorrect translation");
+    }
+
+    #[test]
+    fn infinite_plane_from_points() {
+        let (plane, translation) = InfinitePlane3d::from_points(Vec3::X, Vec3::Z, Vec3::NEG_X);
+        assert_eq!(*plane.normal, Vec3::NEG_Y, "incorrect normal");
         assert_eq!(translation, Vec3::Z * 0.33333334, "incorrect translation");
     }
 

crates/bevy_math/src/ray.rs

@@ -1,5 +1,5 @@
 use crate::{
-    primitives::{Plane2d, Plane3d},
+    primitives::{InfinitePlane3d, Plane2d},
     Dir2, Dir3, Vec2, Vec3,
 };
 
@@ -79,7 +79,7 @@ impl Ray3d {
 
     /// Get the distance to a plane if the ray intersects it
     #[inline]
-    pub fn intersect_plane(&self, plane_origin: Vec3, plane: Plane3d) -> Option<f32> {
+    pub fn intersect_plane(&self, plane_origin: Vec3, plane: InfinitePlane3d) -> Option<f32> {
         let denominator = plane.normal.dot(*self.direction);
         if denominator.abs() > f32::EPSILON {
             let distance = (plane_origin - self.origin).dot(*plane.normal) / denominator;
@@ -141,37 +141,40 @@ mod tests {
 
         // Orthogonal, and test that an inverse plane_normal has the same result
         assert_eq!(
-            ray.intersect_plane(Vec3::Z, Plane3d::new(Vec3::Z)),
+            ray.intersect_plane(Vec3::Z, InfinitePlane3d::new(Vec3::Z)),
             Some(1.0)
         );
         assert_eq!(
-            ray.intersect_plane(Vec3::Z, Plane3d::new(Vec3::NEG_Z)),
+            ray.intersect_plane(Vec3::Z, InfinitePlane3d::new(Vec3::NEG_Z)),
             Some(1.0)
         );
         assert!(ray
-            .intersect_plane(Vec3::NEG_Z, Plane3d::new(Vec3::Z))
+            .intersect_plane(Vec3::NEG_Z, InfinitePlane3d::new(Vec3::Z))
             .is_none());
         assert!(ray
-            .intersect_plane(Vec3::NEG_Z, Plane3d::new(Vec3::NEG_Z))
+            .intersect_plane(Vec3::NEG_Z, InfinitePlane3d::new(Vec3::NEG_Z))
             .is_none());
 
         // Diagonal
         assert_eq!(
-            ray.intersect_plane(Vec3::Z, Plane3d::new(Vec3::ONE)),
+            ray.intersect_plane(Vec3::Z, InfinitePlane3d::new(Vec3::ONE)),
             Some(1.0)
         );
         assert!(ray
-            .intersect_plane(Vec3::NEG_Z, Plane3d::new(Vec3::ONE))
+            .intersect_plane(Vec3::NEG_Z, InfinitePlane3d::new(Vec3::ONE))
             .is_none());
 
         // Parallel
         assert!(ray
-            .intersect_plane(Vec3::X, Plane3d::new(Vec3::X))
+            .intersect_plane(Vec3::X, InfinitePlane3d::new(Vec3::X))
             .is_none());
 
         // Parallel with simulated rounding error
         assert!(ray
-            .intersect_plane(Vec3::X, Plane3d::new(Vec3::X + Vec3::Z * f32::EPSILON))
+            .intersect_plane(
+                Vec3::X,
+                InfinitePlane3d::new(Vec3::X + Vec3::Z * f32::EPSILON)
+            )
             .is_none());
     }
 }

crates/bevy_reflect/src/impls/math/primitives3d.rs

@@ -1,6 +1,6 @@
 use crate as bevy_reflect;
 use crate::{ReflectDeserialize, ReflectSerialize};
-use bevy_math::{primitives::*, Dir3, Vec3};
+use bevy_math::{primitives::*, Dir3, Vec2, Vec3};
 use bevy_reflect_derive::impl_reflect;
 
 impl_reflect!(
@@ -16,6 +16,15 @@ impl_reflect!(
     #[type_path = "bevy_math::primitives"]
     struct Plane3d {
         normal: Dir3,
+        half_size: Vec2,
+    }
+);
+
+impl_reflect!(
+    #[reflect(Debug, PartialEq, Serialize, Deserialize)]
+    #[type_path = "bevy_math::primitives"]
+    struct InfinitePlane3d {
+        normal: Dir3,
     }
 );
 

crates/bevy_render/src/mesh/primitives/dim3/plane.rs

@@ -7,21 +7,10 @@ use crate::{
 };
 
 /// A builder used for creating a [`Mesh`] with a [`Plane3d`] shape.
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, Default)]
 pub struct PlaneMeshBuilder {
     /// The [`Plane3d`] shape.
     pub plane: Plane3d,
-    /// Half the size of the plane mesh.
-    pub half_size: Vec2,
-}
-
-impl Default for PlaneMeshBuilder {
-    fn default() -> Self {
-        Self {
-            plane: Plane3d::default(),
-            half_size: Vec2::ONE,
-        }
-    }
 }
 
 impl PlaneMeshBuilder {
@@ -29,8 +18,10 @@ impl PlaneMeshBuilder {
     #[inline]
     pub fn new(normal: Dir3, size: Vec2) -> Self {
         Self {
-            plane: Plane3d { normal },
-            half_size: size / 2.0,
+            plane: Plane3d {
+                normal,
+                half_size: size / 2.0,
+            },
         }
     }
 
@@ -38,8 +29,10 @@ impl PlaneMeshBuilder {
     #[inline]
     pub fn from_size(size: Vec2) -> Self {
         Self {
-            half_size: size / 2.0,
-            ..Default::default()
+            plane: Plane3d {
+                half_size: size / 2.0,
+                ..Default::default()
+            },
         }
     }
 
@@ -48,8 +41,10 @@ impl PlaneMeshBuilder {
     #[inline]
     pub fn from_length(length: f32) -> Self {
         Self {
-            half_size: Vec2::splat(length) / 2.0,
-            ..Default::default()
+            plane: Plane3d {
+                half_size: Vec2::splat(length) / 2.0,
+                ..Default::default()
+            },
         }
     }
 
@@ -57,14 +52,17 @@ impl PlaneMeshBuilder {
     #[inline]
     #[doc(alias = "facing")]
     pub fn normal(mut self, normal: Dir3) -> Self {
-        self.plane = Plane3d { normal };
+        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.half_size = Vec2::new(width, height) / 2.0;
+        self.plane.half_size = Vec2::new(width, height) / 2.0;
         self
     }
 
@@ -72,10 +70,10 @@ impl PlaneMeshBuilder {
     pub fn build(&self) -> Mesh {
         let rotation = Quat::from_rotation_arc(Vec3::Y, *self.plane.normal);
         let positions = vec![
-            rotation * Vec3::new(self.half_size.x, 0.0, -self.half_size.y),
-            rotation * Vec3::new(-self.half_size.x, 0.0, -self.half_size.y),
-            rotation * Vec3::new(-self.half_size.x, 0.0, self.half_size.y),
-            rotation * Vec3::new(self.half_size.x, 0.0, self.half_size.y),
+            rotation * Vec3::new(self.plane.half_size.x, 0.0, -self.plane.half_size.y),
+            rotation * Vec3::new(-self.plane.half_size.x, 0.0, -self.plane.half_size.y),
+            rotation * Vec3::new(-self.plane.half_size.x, 0.0, self.plane.half_size.y),
+            rotation * Vec3::new(self.plane.half_size.x, 0.0, self.plane.half_size.y),
         ];
 
         let normals = vec![self.plane.normal.to_array(); 4];
@@ -97,10 +95,7 @@ impl Meshable for Plane3d {
     type Output = PlaneMeshBuilder;
 
     fn mesh(&self) -> Self::Output {
-        PlaneMeshBuilder {
-            plane: *self,
-            ..Default::default()
-        }
+        PlaneMeshBuilder { plane: *self }
     }
 }
 

examples/3d/3d_viewport_to_world.rs

@@ -29,7 +29,8 @@ fn draw_cursor(
     };
 
     // Calculate if and where the ray is hitting the ground plane.
-    let Some(distance) = ray.intersect_plane(ground.translation(), Plane3d::new(ground.up()))
+    let Some(distance) =
+        ray.intersect_plane(ground.translation(), InfinitePlane3d::new(ground.up()))
     else {
         return;
     };

examples/3d/irradiance_volumes.rs

@@ -499,7 +499,7 @@ fn handle_mouse_clicks(
     let Some(ray) = camera.viewport_to_world(camera_transform, mouse_position) else {
         return;
     };
-    let Some(ray_distance) = ray.intersect_plane(Vec3::ZERO, Plane3d::new(Vec3::Y)) else {
+    let Some(ray_distance) = ray.intersect_plane(Vec3::ZERO, InfinitePlane3d::new(Vec3::Y)) else {
         return;
     };
     let plane_intersection = ray.origin + ray.direction.normalize() * ray_distance;

examples/math/render_primitives.rs

@@ -166,7 +166,10 @@ const TRIANGLE: Triangle2d = Triangle2d {
 };
 
 const PLANE_2D: Plane2d = Plane2d { normal: Dir2::Y };
-const PLANE_3D: Plane3d = Plane3d { normal: Dir3::Y };
+const PLANE_3D: Plane3d = Plane3d {
+    normal: Dir3::Y,
+    half_size: Vec2::new(BIG_3D, BIG_3D),
+};
 
 const LINE2D: Line2d = Line2d { direction: Dir2::X };
 const LINE3D: Line3d = Line3d { direction: Dir3::X };

examples/stress_tests/many_cubes.rs

@@ -388,6 +388,7 @@ fn init_meshes(args: &Args, assets: &mut Assets<Mesh>) -> Vec<(Handle<Mesh>, Tra
                 assets.add(
                     Plane3d {
                         normal: Dir3::NEG_Z,
+                        half_size: Vec2::splat(0.5),
                     }
                     .mesh()
                     .size(radius, radius),