From 1f1d9c5625b3907a8a23a55cfc023b0c02facc6a Mon Sep 17 00:00:00 2001
From: Treeco <5021038-Treeco@users.noreply.gitlab.com>
Date: Thu, 9 Jul 2020 15:46:00 +0100
Subject: [PATCH 1/2] Reset rather than accumulate velocity when stuck or in
 unloaded chunks

---
 common/src/sys/phys.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/common/src/sys/phys.rs b/common/src/sys/phys.rs
index d57ef92df1..560adeb196 100644
--- a/common/src/sys/phys.rs
+++ b/common/src/sys/phys.rs
@@ -134,6 +134,7 @@ impl<'a> System<'a> for Sys {
                 let dt_lerp = 0.2;
                 (vel.0 * dt_lerp + old_vel.0 * (1.0 - dt_lerp)) * dt.0
             } else {
+                vel.0 = Vec3::zero();
                 Vec3::zero()
             };
 
@@ -319,6 +320,7 @@ impl<'a> System<'a> for Sys {
                         }
 
                         if attempts == MAX_ATTEMPTS {
+                            vel.0 = Vec3::zero();
                             pos.0 = old_pos;
                             break;
                         }

From c7e8a6bfaea65edf05fa9b1d3fc36e529fd58ec5 Mon Sep 17 00:00:00 2001
From: Imbris <imbrisf@gmail.com>
Date: Sat, 18 Jul 2020 07:08:38 -0400
Subject: [PATCH 2/2] Remove gravity rather than reset velocity in unloaded
 chunks

---
 common/src/sys/phys.rs | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/common/src/sys/phys.rs b/common/src/sys/phys.rs
index 560adeb196..29242556d4 100644
--- a/common/src/sys/phys.rs
+++ b/common/src/sys/phys.rs
@@ -117,7 +117,12 @@ impl<'a> System<'a> for Sys {
                 } else {
                     0.0
                 });
-            let downward_force = if physics_state.in_fluid {
+            let in_loaded_chunk = terrain
+                .get_key(terrain.pos_key(pos.0.map(|e| e.floor() as i32)))
+                .is_some();
+            let downward_force = if !in_loaded_chunk {
+                0.0 // No gravity in unloaded chunks
+            } else if physics_state.in_fluid {
                 (1.0 - BOUYANCY) * GRAVITY
             } else {
                 GRAVITY
@@ -125,16 +130,12 @@ impl<'a> System<'a> for Sys {
             vel.0 = integrate_forces(dt.0, vel.0, downward_force, friction);
 
             // Don't move if we're not in a loaded chunk
-            let mut pos_delta = if terrain
-                .get_key(terrain.pos_key(pos.0.map(|e| e.floor() as i32)))
-                .is_some()
-            {
+            let mut pos_delta = if in_loaded_chunk {
                 // this is an approximation that allows most framerates to
                 // behave in a similar manner.
                 let dt_lerp = 0.2;
                 (vel.0 * dt_lerp + old_vel.0 * (1.0 - dt_lerp)) * dt.0
             } else {
-                vel.0 = Vec3::zero();
                 Vec3::zero()
             };