diff --git a/src/pipeline/narrow_phase/contact_generator/default_contact_dispatcher.rs b/src/pipeline/narrow_phase/contact_generator/default_contact_dispatcher.rs
index d041e5d35..43545c3fc 100644
--- a/src/pipeline/narrow_phase/contact_generator/default_contact_dispatcher.rs
+++ b/src/pipeline/narrow_phase/contact_generator/default_contact_dispatcher.rs
@@ -51,8 +51,8 @@ impl<N: RealField> ContactDispatcher<N> for DefaultContactDispatcher {
 
         if a_is_heightfield || b_is_heightfield {
             return Some(wrap(
-                flip,
-                HeightFieldShapeManifoldGenerator::<N>::new(b_is_heightfield),
+                flip ^ b_is_heightfield,
+                HeightFieldShapeManifoldGenerator::<N>::new(),
             ));
         } else if a_is_capsule && b_is_capsule {
             Some(wrap(flip, CapsuleCapsuleManifoldGenerator::<N>::new()))
diff --git a/src/pipeline/narrow_phase/contact_generator/heightfield_shape_manifold_generator.rs b/src/pipeline/narrow_phase/contact_generator/heightfield_shape_manifold_generator.rs
index c1cbbd940..13c6fdd7b 100644
--- a/src/pipeline/narrow_phase/contact_generator/heightfield_shape_manifold_generator.rs
+++ b/src/pipeline/narrow_phase/contact_generator/heightfield_shape_manifold_generator.rs
@@ -10,16 +10,14 @@ use std::collections::{hash_map::Entry, HashMap};
 /// Collision detector between an heightfield and another shape.
 pub struct HeightFieldShapeManifoldGenerator<N: RealField> {
     sub_detectors: HashMap<usize, (ContactAlgorithm<N>, usize), DeterministicState>,
-    flip: bool,
     timestamp: usize,
 }
 
 impl<N: RealField> HeightFieldShapeManifoldGenerator<N> {
     /// Creates a new collision detector between an heightfield and another shape.
-    pub fn new(flip: bool) -> HeightFieldShapeManifoldGenerator<N> {
+    pub fn new() -> HeightFieldShapeManifoldGenerator<N> {
         HeightFieldShapeManifoldGenerator {
             sub_detectors: HashMap::with_hasher(DeterministicState),
-            flip,
             timestamp: 0,
         }
     }
@@ -47,20 +45,27 @@ impl<N: RealField> HeightFieldShapeManifoldGenerator<N> {
             .entry(i)
         {
             Entry::Occupied(mut entry) => {
-                let ok = if self.flip {
-                    entry.get_mut().0.generate_contacts(
-                        dispatcher,
-                        m2,
-                        g2,
-                        proc2,
-                        m1,
-                        elt1,
-                        Some(&(proc1, part_proc1)),
-                        prediction,
-                        manifold,
-                    )
-                } else {
-                    entry.get_mut().0.generate_contacts(
+                let ok = entry.get_mut().0.generate_contacts(
+                    dispatcher,
+                    m1,
+                    elt1,
+                    Some(&(proc1, part_proc1)),
+                    m2,
+                    g2,
+                    proc2,
+                    prediction,
+                    manifold,
+                );
+
+                if ok {
+                    entry.get_mut().1 = self.timestamp;
+                }
+            }
+            Entry::Vacant(entry) => {
+                let new_detector = dispatcher.get_contact_algorithm(elt1, g2);
+
+                if let Some(mut new_detector) = new_detector {
+                    let _ = new_detector.generate_contacts(
                         dispatcher,
                         m1,
                         elt1,
@@ -70,46 +75,7 @@ impl<N: RealField> HeightFieldShapeManifoldGenerator<N> {
                         proc2,
                         prediction,
                         manifold,
-                    )
-                };
-
-                if ok {
-                    entry.get_mut().1 = self.timestamp;
-                }
-            }
-            Entry::Vacant(entry) => {
-                let new_detector = if self.flip {
-                    dispatcher.get_contact_algorithm(g2, elt1)
-                } else {
-                    dispatcher.get_contact_algorithm(elt1, g2)
-                };
-
-                if let Some(mut new_detector) = new_detector {
-                    if self.flip {
-                        let _ = new_detector.generate_contacts(
-                            dispatcher,
-                            m2,
-                            g2,
-                            proc2,
-                            m1,
-                            elt1,
-                            Some(&(proc1, part_proc1)),
-                            prediction,
-                            manifold,
-                        );
-                    } else {
-                        let _ = new_detector.generate_contacts(
-                            dispatcher,
-                            m1,
-                            elt1,
-                            Some(&(proc1, part_proc1)),
-                            m2,
-                            g2,
-                            proc2,
-                            prediction,
-                            manifold,
-                        );
-                    }
+                    );
                     let _ = entry.insert((new_detector, self.timestamp));
                 }
             }
@@ -135,16 +101,9 @@ impl<N: RealField> ContactManifoldGenerator<N> for HeightFieldShapeManifoldGener
         prediction: &ContactPrediction<N>,
         manifold: &mut ContactManifold<N>,
     ) -> bool {
-        if !self.flip {
-            if let Some(hf) = a.as_shape::<HeightField<N>>() {
-                self.do_update(d, ma, hf, proc1, mb, b, proc2, prediction, manifold);
-                return true;
-            }
-        } else {
-            if let Some(hf) = b.as_shape::<HeightField<N>>() {
-                self.do_update(d, mb, hf, proc2, ma, a, proc1, prediction, manifold);
-                return true;
-            }
+        if let Some(hf) = a.as_shape::<HeightField<N>>() {
+            self.do_update(d, ma, hf, proc1, mb, b, proc2, prediction, manifold);
+            return true;
         }
 
         return false;