<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>Animats</author><text>That&amp;#x27;s a consequence of using impulse-constraint contact simulation on ragdolls.  If you use spring-damper contact simulation, the motion is better, but the compute cost is higher.  Impulse-constraint simulations have instantaneous velocity changes, which looks wrong for large objects.  I call this the &amp;quot;boink&amp;quot; problem. Here&amp;#x27;s what it looks like with nonlinear spring-damper contact simulation.[1][2]&lt;p&gt;I did those animations back in 1996-1997.  Havok licensed the patent rights from me, but switched over to impulse-constraint because it was faster and could be done on the 32-bit FPUs of game consoles.  Spring-damper simulation has a reputation for failing badly under high forces (&amp;quot;Trespasser&amp;quot;, an early Jurassic Park game, was a disaster because of this), but I figured out how to fix that.  (You have to use nonlinear simulated springs, and then, having created an insanely stiff system of differential equations, figure out how to integrate them.  This can be done well, but it&amp;#x27;s hard to do it in fixed time, which is a problem for games.)&lt;p&gt;Havok didn&amp;#x27;t do too well in their first years. They overexpanded, more or less went broke, a new group of investors and management took over and downsized, and a few years later the new investors exited by selling the company to Intel. The founders didn&amp;#x27;t come out of it very well.&lt;p&gt;[1] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.youtube.com&amp;#x2F;watch?v=5lHqEwk7YHs&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.youtube.com&amp;#x2F;watch?v=5lHqEwk7YHs&lt;/a&gt;
[2] &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.youtube.com&amp;#x2F;watch?v=-DaWIHc1VLY&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.youtube.com&amp;#x2F;watch?v=-DaWIHc1VLY&lt;/a&gt;</text><parent_chain><item><author>brobinson</author><text>A piece of middleware used in seemingly every single AAA game in the last decade... seems like a solid investment!&lt;p&gt;That said, when I see a Havok splash screen when a game is launching, it means &amp;quot;prepare for unrealistic ragdolls&amp;quot; to me.  I wish they would tone down how loose the physics on ragdolls are and end up with something more like this:  &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.youtube.com&amp;#x2F;watch?v=Qi5adyccoKI&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.youtube.com&amp;#x2F;watch?v=Qi5adyccoKI&lt;/a&gt;</text></item></parent_chain></comment><story><title>Microsoft acquires Havok</title><url>http://blogs.microsoft.com/blog/2015/10/02/havok-to-join-microsoft/</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>reubenmorais</author><text>If you look for videos of people actually getting hit by high powered weapons, or high speed cars, you&amp;#x27;ll realize that what&amp;#x27;s unrealistic is your expectation. People in those cases behave a lot like ragdolls, we just don&amp;#x27;t see it in real life very often (or at all), so don&amp;#x27;t know what to expect.&lt;p&gt;Now this is just me making up theories, but I think that effect is exacerbated by the fact that kinetic energy scales with the square of velocity, and humans tend to think linearly.</text><parent_chain><item><author>brobinson</author><text>A piece of middleware used in seemingly every single AAA game in the last decade... seems like a solid investment!&lt;p&gt;That said, when I see a Havok splash screen when a game is launching, it means &amp;quot;prepare for unrealistic ragdolls&amp;quot; to me.  I wish they would tone down how loose the physics on ragdolls are and end up with something more like this:  &lt;a href=&quot;https:&amp;#x2F;&amp;#x2F;www.youtube.com&amp;#x2F;watch?v=Qi5adyccoKI&quot; rel=&quot;nofollow&quot;&gt;https:&amp;#x2F;&amp;#x2F;www.youtube.com&amp;#x2F;watch?v=Qi5adyccoKI&lt;/a&gt;</text></item></parent_chain></comment><story><title>Microsoft acquires Havok</title><url>http://blogs.microsoft.com/blog/2015/10/02/havok-to-join-microsoft/</url></story>