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-rw-r--r--src/dynamics/mass_properties_cone.rs30
-rw-r--r--src/dynamics/mod.rs2
2 files changed, 32 insertions, 0 deletions
diff --git a/src/dynamics/mass_properties_cone.rs b/src/dynamics/mass_properties_cone.rs
new file mode 100644
index 0000000..0fb61b6
--- /dev/null
+++ b/src/dynamics/mass_properties_cone.rs
@@ -0,0 +1,30 @@
+use crate::dynamics::MassProperties;
+use crate::geometry::Cone;
+use crate::math::{Point, PrincipalAngularInertia, Rotation, Vector};
+
+impl MassProperties {
+ pub(crate) fn cone_y_volume_unit_inertia(
+ half_height: f32,
+ radius: f32,
+ ) -> (f32, PrincipalAngularInertia<f32>) {
+ let volume = radius * radius * std::f32::consts::PI * half_height * 2.0 / 3.0;
+ let sq_radius = radius * radius;
+ let sq_height = half_height * half_height * 4.0;
+ let off_principal = sq_radius * 3.0 / 20.0 + sq_height * 3.0 / 5.0;
+ let principal = sq_radius * 3.0 / 10.0;
+
+ (volume, Vector::new(off_principal, principal, off_principal))
+ }
+
+ pub(crate) fn from_cone(density: f32, half_height: f32, radius: f32) -> Self {
+ let (cyl_vol, cyl_unit_i) = Self::cone_y_volume_unit_inertia(half_height, radius);
+ let cyl_mass = cyl_vol * density;
+
+ Self::with_principal_inertia_frame(
+ Point::new(0.0, -half_height / 2.0, 0.0),
+ cyl_mass,
+ cyl_unit_i * cyl_mass,
+ Rotation::identity(),
+ )
+ }
+}
diff --git a/src/dynamics/mod.rs b/src/dynamics/mod.rs
index 512bd8b..10cdd29 100644
--- a/src/dynamics/mod.rs
+++ b/src/dynamics/mod.rs
@@ -22,6 +22,8 @@ mod joint;
mod mass_properties;
mod mass_properties_ball;
mod mass_properties_capsule;
+#[cfg(feature = "dim3")]
+mod mass_properties_cone;
mod mass_properties_cuboid;
mod mass_properties_cylinder;
#[cfg(feature = "dim2")]