Fix 2D compilation.

src_testbed/objects/convex.rs

@@ -5,7 +5,7 @@ use crate::math::Vector;
 use crate::math::{Isometry, Point};
 use crate::objects::node::{self, GraphicsNode};
 use kiss3d::window::Window;
-use na::{Isometry3, Point3};
+use na::Point3;
 use rapier::geometry::{ColliderHandle, ColliderSet};
 
 pub struct Convex {
@@ -13,13 +13,13 @@ pub struct Convex {
     base_color: Point3<f32>,
     gfx: GraphicsNode,
     body: ColliderHandle,
-    delta: Isometry3<f32>,
+    delta: Isometry<f32>,
 }
 
 impl Convex {
     pub fn new(
         body: ColliderHandle,
-        delta: Isometry3<f32>,
+        delta: Isometry<f32>,
         vertices: Vec<Point<f32>>,
         #[cfg(feature = "dim3")] indices: Vec<Point<u32>>,
         color: Point3<f32>,