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	<title>Real-Time Physics Simulation Forum</title>
	
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	<updated>2013-05-11T12:09:54+00:00</updated>

	<author><name><![CDATA[Real-Time Physics Simulation Forum]]></name></author>
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		<entry>
		<author><name><![CDATA[mikeshafer]]></name></author>
		<updated>2013-05-11T12:09:54+00:00</updated>

		<published>2013-05-11T12:09:54+00:00</published>
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		<title type="html"><![CDATA[Re: Angular velocity integration]]></title>

		
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Nevermind!  It works even with angular velocity not divided by 2.  I don't know what I did, but it does the teeter-totter that Erin describes in his paper and then stabilizes due to the caching of lambda values.  Oh, and the bias calculation for the normal constraint: I'm not dividing by anything--it's straight up difference in velocity + penetration / dt.  It's working and I'm happy.  I can get some sleep now.<br><br>Mike<p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=9133">mikeshafer</a> — Sat May 11, 2013 12:09 pm</p><hr />
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		<entry>
		<author><name><![CDATA[mikeshafer]]></name></author>
		<updated>2013-05-11T12:04:34+00:00</updated>

		<published>2013-05-11T12:04:34+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=30688#p30688</id>
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		<title type="html"><![CDATA[Re: Angular velocity integration]]></title>

		
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Here is my success story*.  It's got an asterisk because it's dependent on dividing angular velocity by 2, lol.<br><br><img src="http://www.mikeshafer2009.com/img/4stack.png" class="postimage" alt="Image"><br><br>Mike<p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=9133">mikeshafer</a> — Sat May 11, 2013 12:04 pm</p><hr />
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		<entry>
		<author><name><![CDATA[mikeshafer]]></name></author>
		<updated>2013-05-11T10:57:40+00:00</updated>

		<published>2013-05-11T10:57:40+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=30687#p30687</id>
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		<title type="html"><![CDATA[Angular velocity integration]]></title>

		
		<content type="html" xml:base="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=30687#p30687"><![CDATA[
Hi folks,<br><br>Sorry for the noob question, but I got my boxes stacking by dividing the angular velocity by 1/2.  Erin's Iterative dynamics states that the *quaternion* integration is achieved by:<br><br>q2 = q1 + dt/2 * q1 * w2<br><br>The factor of 1/2 in there seems to be required for the quaternion integration.  I don't do my integration via quaternions, I do it with matrix math.  Do I still need to divide by 2 for a matrix integration?<br><br>Thanks in advance,<br>Mike<p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=9133">mikeshafer</a> — Sat May 11, 2013 10:57 am</p><hr />
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