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	<title>Real-Time Physics Simulation Forum</title>
	
	<link href="https://pybullet.org/Bullet/phpBB3/index.php" />
	<updated>2008-11-13T20:18:47+00:00</updated>

	<author><name><![CDATA[Real-Time Physics Simulation Forum]]></name></author>
	<id>https://pybullet.org/Bullet/phpBB3/app.php/feed/topic/2840</id>

		<entry>
		<author><name><![CDATA[JamesH]]></name></author>
		<updated>2008-11-13T20:18:47+00:00</updated>

		<published>2008-11-13T20:18:47+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11357#p11357</id>
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		<title type="html"><![CDATA[Re: ColladaConverter]]></title>

		
		<content type="html" xml:base="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11357#p11357"><![CDATA[
Sorry Erwin, ignore my post, I meant &lt;mesh&gt; not &lt;convex&gt;, but I can see that there is a &lt;convex_mesh&gt; tag that refers to the previous &lt;mesh&gt; section.<p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=1035">JamesH</a> — Thu Nov 13, 2008 8:18 pm</p><hr />
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	</entry>
		<entry>
		<author><name><![CDATA[Erwin Coumans]]></name></author>
		<updated>2008-11-13T19:39:37+00:00</updated>

		<published>2008-11-13T19:39:37+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11355#p11355</id>
		<link href="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11355#p11355"/>
		<title type="html"><![CDATA[Re: ColladaConverter]]></title>

		
		<content type="html" xml:base="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11355#p11355"><![CDATA[
<blockquote class="uncited"><div>One observation from the outputted file, is that the hulls are tagged as &lt;convex&gt;, but looking at Chapter 6 of the COLLADA specs for 1.4 and 1.5, the Analytical shapes, should it be &lt;convex_mesh&gt; ?</div></blockquote>Bullet doesn't produce the exported XML, it relies on COLLADA_DOM. Are you using Bullet's ColladaConverter, in combination with the COLLADA DOM &amp; libxml from Bullet/Extras folder?<br>I just tried to convert the convex parts from Bullet/Demos/ConvexDecompositionDemo, and the output is fine:<blockquote class="uncited"><div>&lt;convex_mesh convex_hull_of="#RenderMeshBulletUnnamed-0-Geometry"/&gt;</div></blockquote>How can you reproduce this &lt;convex&gt; tag? Can you attached a zipped exported file?<br>Thanks,<br>Erwin<dl class="file"><dt><span class="imageset icon_topic_attach"></span> <a class="postlink" href="https://pybullet.org/Bullet/phpBB3/download/file.php?id=212">convex_compounds.zip</a></dt></dl><p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=2">Erwin Coumans</a> — Thu Nov 13, 2008 7:39 pm</p><hr />
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	</entry>
		<entry>
		<author><name><![CDATA[JamesH]]></name></author>
		<updated>2008-11-13T19:10:36+00:00</updated>

		<published>2008-11-13T19:10:36+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11354#p11354</id>
		<link href="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11354#p11354"/>
		<title type="html"><![CDATA[Re: ColladaConverter]]></title>

		
		<content type="html" xml:base="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11354#p11354"><![CDATA[
I modified the three changes identified in the GoogleCode's <a href="http://code.google.com/p/bullet/source/detail?r=1502" class="postlink">change-set</a> (I didn't have time to merge in 2.7.3), and it works fine now thanks. <br><br>One observation from the outputted file, is that the hulls are tagged as &lt;convex&gt;, but looking at Chapter 6 of the COLLADA specs for 1.4 and 1.5, the Analytical shapes, should it be &lt;convex_mesh&gt; ?<br><br>Anyway, once again thanks for the fix.<p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=1035">JamesH</a> — Thu Nov 13, 2008 7:10 pm</p><hr />
]]></content>
	</entry>
		<entry>
		<author><name><![CDATA[Erwin Coumans]]></name></author>
		<updated>2008-11-12T23:16:38+00:00</updated>

		<published>2008-11-12T23:16:38+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11336#p11336</id>
		<link href="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11336#p11336"/>
		<title type="html"><![CDATA[Re: ColladaConverter]]></title>

		
		<content type="html" xml:base="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11336#p11336"><![CDATA[
The latest trunk and Bullet 2.73 RC3 has compound collision shape export in the ColladaConverter:<br><a href="http://code.google.com/p/bullet/downloads/detail?name=bullet-2.73-rc3.zip" class="postlink">http://code.google.com/p/bullet/downloa ... 73-rc3.zip</a><br><br>Can you test this (or attached zipfile), and report if that works for you?<br><br>Thanks,<br>Erwin<dl class="file"><dt><span class="imageset icon_topic_attach"></span> <a class="postlink" href="https://pybullet.org/Bullet/phpBB3/download/file.php?id=211">BulletColladaConverter.zip</a></dt></dl><p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=2">Erwin Coumans</a> — Wed Nov 12, 2008 11:16 pm</p><hr />
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	</entry>
		<entry>
		<author><name><![CDATA[JamesH]]></name></author>
		<updated>2008-11-12T17:43:53+00:00</updated>

		<published>2008-11-12T17:43:53+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11330#p11330</id>
		<link href="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11330#p11330"/>
		<title type="html"><![CDATA[Re: ColladaConverter]]></title>

		
		<content type="html" xml:base="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11330#p11330"><![CDATA[
I am going to go through it in the next couple of days and see if I can track the issue down. I'll let you know if I find the problem.<p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=1035">JamesH</a> — Wed Nov 12, 2008 5:43 pm</p><hr />
]]></content>
	</entry>
		<entry>
		<author><name><![CDATA[Erwin Coumans]]></name></author>
		<updated>2008-11-12T17:27:27+00:00</updated>

		<published>2008-11-12T17:27:27+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11328#p11328</id>
		<link href="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11328#p11328"/>
		<title type="html"><![CDATA[Re: ColladaConverter]]></title>

		
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Cool, that is interesting work, thanks for sharing.<br><br>There is probably some issue with the BulletColladaConverter compound export.<br>In particular, the COMPOUND_SHAPE_PROXYTYPE case in void ColladaConverter::buildShape, in Bullet\Extras\BulletColladaConverter\ColladaConverter.cpp.<br><br>I'll see if we can fix it. Obviously, if you fix it before us, we accept contributions.<br><br>Please keep us up-to-date and let us know if there are any issues,<br>Thanks,<br>Erwin<p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=2">Erwin Coumans</a> — Wed Nov 12, 2008 5:27 pm</p><hr />
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	</entry>
		<entry>
		<author><name><![CDATA[JamesH]]></name></author>
		<updated>2008-11-11T21:44:23+00:00</updated>

		<published>2008-11-11T21:44:23+00:00</published>
		<id>https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11310#p11310</id>
		<link href="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11310#p11310"/>
		<title type="html"><![CDATA[ColladaConverter]]></title>

		
		<content type="html" xml:base="https://pybullet.org/Bullet/phpBB3/viewtopic.php?p=11310#p11310"><![CDATA[
I'm currently implementing Bullet in the C4 Engine to mirror a PhysX implementation that I've been working on, and I've hit a bit of a wall with regards to saving compound rigid bodies, ie made up from numerous convex hulls (generated using ConvexDecomposition)<br><br>At the moment I am using ConvexDecomposition on a test model of a column, it works fine decomposing at runtime but obviously it is slow. So I'm saving it out to a .dae file to load back in at runtime rather than decompose it every time. The problem I have is that the collada file that is generated of the saved compound rigid body does not contain multiple convex hulls that were generated, just a single one.<br><br>If I then run the same scene in PhysX (both are using the same ConvexDecomp code) and save a dae file out using NXUStream the file is completely different, but if I then load that file into the bullet scene it loads fine and all of the hulls are created correctly.<br><br><img src="http://teamhstudios.com/downloads/C4-1.4.10-BU-001.jpg" class="postimage" alt="Image"><br>The image shows a yellow column that has the collision mesh generated at runtime and the red one loaded the file generated from NXUStream, Column-PhysX.dae - the Bullet debug is turned on.<br><br>My question is, do I have to do anything special when saving a btDynamicsWorld, I just create the world, create one rigid body (the compound one) and save it. I created my own class that inherits from ColladaConverter and override the ::createConvexHullShape() and ::createCompoundShape() to check that the convex hulls are being created when it loads and just one hull is created when loading the Bullet generated collada file, Column-Bullet.dae.<br><br>The two files are here if anyone wants to check them out. <div class="inline-attachment"><dl class="file"><dt><span class="imageset icon_topic_attach"></span> <a class="postlink" href="https://pybullet.org/Bullet/phpBB3/download/file.php?id=209">COLLADAFiles.zip</a></dt></dl></div>Many thanks<br><br>James.<p>Statistics: Posted by <a href="https://pybullet.org/Bullet/phpBB3/memberlist.php?mode=viewprofile&amp;u=1035">JamesH</a> — Tue Nov 11, 2008 9:44 pm</p><hr />
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