I thought so too; but that&#x27;s what I read, as what happens when Euler curves were used in practice (which they were). Unfortunately, I didn&#x27;t get to the point of trying it out for myself in my game.<p>[BTW: Like a bob-sled track, I did find that cross-sections that were sine waves or quadratic did feel strikingly smooth - those being smooth, with smooth deviratives, smooth derivatives of derivatives, and so on.]<p>If you imagine an x-y graph of force over time for a track that went like (start in a straight, an Euler curve to begin the turn, some time in an circular arc, and a reverse Euler to straighten it, end in a straight), the graph would be (level, slope up, level, slope down, level):<p><pre><code>    _
  _&#x2F; \_</code></pre>
Apparently, humans are sensitive to the change between levels and linear slopes. Lines are uncommon in nature [though gravity is constant acceleration...?]. Perhaps related to inverse kinematics in limb movement? &quot;Jolt&quot; may be the wrong description.