Don't set the player to previous position when uncrouching.

include/Engine/Input/FirstPersonInputController.h

@@ -18,6 +18,7 @@ public:
     virtual const glm::vec3 Rotation() const { return m_Rotation; }
     virtual bool Jumping() const { return m_Jumping; }
     virtual bool Crouching() const { return m_Crouching; }
+    virtual bool CrouchingLastFrame() const { return m_CrouchingLastFrame; }
     virtual bool DoubleJumping() const { return m_DoubleJumping; }
     virtual void SetDoubleJumping(bool isDoubleJumping) {
         m_DoubleJumping = isDoubleJumping;
@@ -43,6 +44,7 @@ protected:
     bool m_Jumping = false;
     bool m_DoubleJumping = false;
     bool m_Crouching = false;
+    bool m_CrouchingLastFrame = false;
     //assault dash membervariables - needed to calculate the doubletap- and dashlogic
     double m_AssaultDashDoubleTapDeltaTime = 0.0;
     double m_DashEffectResetTimer = 0.0;
@@ -82,6 +84,7 @@ void FirstPersonInputController<EventContext>::Reset()
 {
     m_Rotation = glm::vec3(0.f, 0.f, 0.f);
     m_Jumping = false;
+    m_CrouchingLastFrame = m_Crouching;
 }
 
 template <typename EventContext>

resources/Schema/Components/Collidable.xml

@@ -1,3 +1,4 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no" ?>
 <Collidable xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="Collidable.xsd">
+	<JitterGuard>true</JitterGuard>
 </Collidable>

resources/Schema/Components/Collidable.xsd

@@ -7,5 +7,10 @@
 		<xs:annotation>
 			<xs:documentation>Needs a Model or AABB component to work, uses AABB if both are attached.</xs:documentation>
 		</xs:annotation>
+		<xs:complexType>
+			<xs:all>
+				<xs:element name="JitterGuard" type="t:bool" minOccurs="0"/>
+			</xs:all>
+		</xs:complexType>
 	</xs:element>
 </xs:schema>

src/Engine/Collision/CollisionSystem.cpp

@@ -66,7 +66,7 @@ void CollisionSystem::UpdateComponent(EntityWrapper& entity, ComponentWrapper& c
                 }
             }
         }
-
+        bool& jitterGuard = (bool&)entity["Collidable"]["JitterGuard"];
         // Collide against octree items
         m_OctreeResult.clear();
         m_Octree->ObjectsInSameRegion(*boundingBox, m_OctreeResult);
@@ -93,7 +93,7 @@ void CollisionSystem::UpdateComponent(EntityWrapper& entity, ComponentWrapper& c
                 float verticalStepHeight = (float)(double)cPhysics["VerticalStepHeight"];
                 if (Collision::AABBvsTriangles(boxA, model->Vertices(), model->m_Indices, modelMatrix, inOutVelocity, verticalStepHeight, isOnGround, resolutionVector)) {
                     //Move the position to previous position if it is not moving in the xz-plane, else resolve with the resolution vector.
-                    (glm::vec3&)cTransform["Position"] += notMovingxz ? prevPosIt->second - boxA.Origin() : resolutionVector;
+                    (glm::vec3&)cTransform["Position"] += jitterGuard && notMovingxz ? prevPosIt->second - boxA.Origin() : resolutionVector;
                     boxA = *Collision::EntityAbsoluteAABB(entity);
                     cPhysics["Velocity"] = inOutVelocity;
                     if (isOnGround) {
@@ -118,6 +118,7 @@ void CollisionSystem::UpdateComponent(EntityWrapper& entity, ComponentWrapper& c
             (bool)cPhysics["IsOnGround"] = false;
         }
 
+        jitterGuard = true;
         m_PrevPositions[entity] = boxA.Origin();
     }
 }

src/Game/Systems/PlayerMovementSystem.cpp

@@ -273,6 +273,15 @@ void PlayerMovementSystem::updateMovementControllers(double dt)
                     size = glm::vec3(1.f, 1.f, 1.f);
                 } else {
                     size = glm::vec3(1.f, 1.6f, 1.f);
+                    if (controller->CrouchingLastFrame() && player.HasComponent("Collidable")) {
+                        // Disable jitter guard so player doesn't get stuck in the ground.
+                        (bool&)player["Collidable"]["JitterGuard"] = false;
+                        if (isOnGround) {
+                            // The collision should resolve this anyway, but 
+                            // this is more reliable, since the box gets larger.
+                            ((glm::vec3&)cTransform["Position"]).y += 0.3f;
+                        }
+                    }
                 }
             }