Add a bunch of .round()s before conversions

Previously this was leading to inconsistencies when using f32 v.s. f64

src/geom/vec.rs

@@ -208,6 +208,9 @@ impl Vec3 {
             self.with_mag(1.0)
         }
     }
+    pub fn round(&self) -> Vec3 {
+        Self::new(self.x().round(), self.y().round(), self.z().round())
+    }
 }
 
 impl Into<(Flt, Flt, Flt)> for Vec3 {